Pool and Crossdrive

An interesting subset of plants Daniel and I have been finding are food plants.  We are calling these plants waifs -stray plants that crop up here and there, but do not persist or reproduce in the same spot. They may come from seeds people drop from their lunches, plant intentionally, or perhaps come from seed people put out to feed the birds.

We found this little pea along a path in the wooded area between the Pool and the Great Hill.  There was just one lone little plant snuggled up against the fence.  See the black "eye" on the seed?  That is black-eyed pea (Vigna unguiculata subsp. unguiculata).

Vigna unguiculata subsp. unguiculata (Fabaceae) Black-eyed pea 

Vigna unguiculata subsp. unguiculata (Fabaceae) Black-eyed pea 

Two other waifs we commonly find are the tomato (Solanum lycopersicum, formerly Lycopersicon esculentum) and sorghum (Sorghum bicolor). Tomato likely comes from people's lunches and sorghum may come from bird seed.  Feeding birds is a common occurrence in Central Park and sorghum, or milo, is an ingredient in many seed mixes

Solanum lycopersicum, (Solanaceae) Tomato

Sorghum bicolor (Poaceae) Sorghum

This is the time of year to look for asters and goldenrods flowering and fruiting.  There are many goldenrods and they can be a challenge to identify.  This one was delightfully not so difficult to key out. We found this little beauty on the woodland slope between the Pool and the Great Hill. The plant is large-leaved goldenrod (Solidago macrophylla), a native to our area. True to its name, the lower leaves are indeed large. They are sharply toothed and taper abruptly to the leaf stem (petiole).

Solidago macrophylla (Asteraceae) Large-leaved goldenrod

The next two photos show species we did not collect this time because we already have them.  They are the two most common wildflowers in the park. White snakeroot (Ageratina altissima, formerly Eupatorium rugosum) and White wood-aster (Eurybia divaricata, formerly Aster divaricatus). But lest we take them for granted, take a look at their beauty! And remember how important the fall Asteraceae are to wildlife. They provide late season nectar for insects and the insects in turn provide food for some species of migrating birds. 

Ageratina altissima (Asteraceae) White snakeroot

Eurybia divaricata (Asteraceae) White wood-aster

This next species, velvetleaf, Abutilon theophrasti, is a beautiful little plant in the Malvaceae. An annual plant from Asia, it is considered a weed in croplands as well as in horticultural and natural settings.  It is especially a problem for corn growers, causing considerable loss of crops if not aggressively managed. We found a small patch growing in a woodland edge northwest of the North Meadow ballfields.

Abutilon theophrasti (Malvaceae) velvetleaf

Another gorgeous non-native annual we found in the same area is the ivy-leaved morning glory Ipomoea hederacea. I included three photos here because I was fascinated with the striking hair on the stem, fruit and leaves. Although related to the hedge bindweed (Calystegia sepium) and the field bindweed (Convolvulus arvensis), it does not seem to be as aggressive.  

Ipomoea hederacea (Convolvulaceae) ivy-leaved morning glory

Ipomoea hederacea (Convolvulaceae) ivy-leaved morning glory

Ipomoea hederacea (Convolvulaceae) ivy-leaved morning glory

A Trip to the Botanical Garden Herbarium

Last week Marie Winn, Ken Chaya and I trekked up to the New York Botanical Garden for a special tour. Daniel Atha was kind enough to show us around the herbarium and describe step-by-step how plant specimens are vouchered.  It is a time-consuming process involving several people, but in the end you have a beautifully pressed specimen that can be preserved for hundreds of years.

The herbarium at the New York Botanical Garden is the largest herbarium in the Western hemisphere and the third largest in the World.  The herbarium is around 100 years old and contains approximately 7 million specimens from all over the world, the oldest of which date back to the 1760s.

The first stop on our tour was Daniel's office.  In earlier posts, I showed how Daniel presses plants in the field.  Once in the office, he goes through each specimen to make sure they are laid out properly, so that all features can be seen.  Once the specimen is dried, you cannot change the layout, so this is an important step.  He also checks to make sure the number allocated to the specimen matches his notes and identification.

Daniel and Marie in Daniel's office at the New York Botanical Garden

To be dried properly, each plant specimen is pressed in a folded sheet of newspaper and sandwiched between two sheets of blotter paper and two sheets of corrugated cardboard.  All the specimens collected are then stacked.  Moisture moves as a vapor from the plant to the blotter to the cardboard.  The stack is put on a dryer so that warm air can pass through the vents in the cardboard taking all that moisture and evaporating it into the air.

Daniel, Marie and Ken stacking specimens 

Specimens are sandwiched between blotter paper and corrugated cardboard

Insects and fungi are the nemeses of an herbarium collection.  They can destroy specimens in no time at all. In the photo below you can see one such critter that made its way into samples that I collected.  Dermestid beetles are a group of beetles also known as carpet beetles, skin beetles, larder beetles.  They are scavengers that feed on dried plant or animal tissue.  They are very specific about what they feed on.  Some species feed on plants, some on mammals, some on birds, etc.  This species has a fondness for sunflowers, but will probably feed on other plant species as well.  The black specks you see are called frass, (insect poop).  The worm-like creature you see is the larvae (young) of the beetle.

Dermestid beetle feeding on my sunflower specimen

Insects and other organisms (such as fungi) are destroyed by placing the dried plant specimens in a freezer that is kept at -40C. Although some species can survive extreme temperatures, they cannot survive the sudden change from room temp to -40.  All dried specimens go into this freezer for 48 hours. 

-40C freezer

Herbarium speciemns throughout the United States are mounted on a standard size sheet of paper (11 1/2 x 16").  The paper is acid-free cotton rag.  

Mounting paper

The collector of the specimen provides all the information to make a label.  These labels include the scientific name of the species, the location where it was collected, the name of the institute that supported the collection, the name of the collector(s) and the date collected.  Daniel provides all of this information to his assistant who makes the labels and enters the data into the herbarium database.

Specimen and label

The specimen then goes to the mounter.  She carefully glues the specimen to the mounting paper.  Also glued to the paper are the label and an envelope to hold bits of the plant that might break off.  The sheet is stamped with the name of the botanical garden and it is given a bar code.  Once the specimen gets photographed for the database, it gets a stamp saying "imaged".  After the specimen is mounted, it gets put in the -40C freezer a second time to ensure no organisms survived.

Mounting a specimen

The final product

Items, such as fruit, that are too large to mount on the sheet get put in boxes with the same label information and bar code.

Fruit too large to be mounted

A few fresh leaves are quickly dried and preserved in silica to be available for DNA analysis.  This also gets the same label information and its own unique bar code.

Tissue preserved in silica for DNA analysis

Information from each specimen is entered into the herbarium database.  Also included in the database is a photo of the specimen.  To produce the photo, the specimen is placed in a light box that has a camera mounted above.  The photos are high resolution and researchers looking at specimens online usually can see enough detail to make a proper identification.

Preparing a specimen to be photographed

Preparing a specimen to be photographed

Photos of specimens to be added to database

Photos of specimens to be added to database

All collectors must provide all the collection information for each specimen so that labels can be generated. Without this information, the specimen is useless.  This is a time-consuming process that sometimes a collector does not get around to doing.  In that case, a collection can sit on the shelves of the "cold room" for years or even decades.  There are approximately 1 million specimens waiting at any given time to be processed.  Garden researchers process anywhere from 10,000 to 30,000 specimens a year.

Collections stored in the cold room, waiting to be processed

Once all of the above steps are completed, the specimen finally gets filed into the herbarium cabinets. 

The herbarium itself is an entire building with temperature and humidity controlled rooms.  These rooms are lined with cabinets that hold the 7 million specimens.  Each cabinet contains samples from a plant family from a specific part of the world.  

The herbarium

Inside the cabinets, folders group the plants into genera and species.

Specimens filed by family and genus

As a final treat, Daniel ended the tour by showing us some of the oldest specimens in the collection.  He showed us two from Captain Cook's first expedition.  James Cook was a British explorer and navigator who made several expeditions around the globe, including the first European contact with Australia and the Hawaiian islands.  These specimens were collected during his first voyage which lasted from 1768-1771.

Daniel also showed us a specimen collected by Charles Darwin during the Voyage of the Beagle, 1831-1836. Darwin was an English naturalist and geologist.  We know him best for his contributions to the theory of evolution.  The voyage of the Beagle lasted 5 years and went mostly around South America.

It is exciting to think that our specimens might be studied by someone interested in the Flora of Central Park two or three hundred years from now.

Specimen from Captain Cook's voyage

Specimen from Captain Cook's voyage

Some of the oldest specimens in the collection

A moss collected by Darwin

Ramble and North Woods

I went collecting twice last week without Daniel, who was in Maine on another project.  This is a nice challenge for me since I am not as experienced a botanist as Daniel.  I can identify many plants and know how to use field guides to learn the ones I don't know, but when Daniel is there, he knows to search for look-alike species that I might not be aware of.  For instance, the two Japanese knotweed species he taught me to distinguish: Reynoutria japonica and Reynoutria sachalinensis. (see July entry 79th Street Transverse Road. Note that in the blog I used the old genus name for these species, Fallopia).  I did my best and found some good species today and Wednesday.

I met my friend Christina Colón on Wednesday at 103rd and Central Park West.  Christina is an ecology professor at Kingsborough Community College.  We became friends during the year and a half that I worked there.   We walked through the Pool area and into the Woodlands to walk along the Loch and the Meadow.  

In the wooded area on the north side of the Pool we found our first few species in a sunny clearing. Giant ragweed (Ambrosia trifida).  Although this herbaceous plant is native to North America, most people treat it as a weed.  It thrives in disturbed habitats and waste places.  The inflorescences are made up of tiny yellow-green flowers that are not showy and have no petals or sepals.  This species is wind-pollinated and is one of the main sources of hay fever.  This species is what is known as an annual.  It completes it life cycle in one year.  It germinates from a seed in the spring and grows all spring and summer. By August it forms flowers and then fruits.  By the fall when the fruits mature, they release their seeds and the plant dies.  But the species lives on in all those seeds that will germinate next spring.  Compare this life cycle to biennials and perennials described a little further along in this blog.

Ambrosia trifida Asteraceae

Ambrosia trifida Asteraceae

The sunflowers and coneflowers have been used as restorations species by the Conservancy and some now regenerate on their own. There is a lovely stand of brown eyed susans, or thin-leaved cone flower (Rudbeckia triloba) along the 102nd Street crossdrive.  The photo below shows the flowerheads with the distinctive dark discs of the black- and brown eyed susans. But the leaves in the photo are misleading, they belong to the partridge pea (Chamaecrista fasciculata) which was growing in the same area.  The brown eyed susan has variable leaves - the upper leaves are roundish, lower leaves ovate with some having three lobes (hence the name triloba).

Rudbeckia triloba Asteraceae

Chamaecrista fasciculata Fabaceae

On the north side of the 102nd Street cross drive is the Wildflower Meadow.  It is the only meadow of any size in the Park.  When people talk about conservation and restoration of natural areas, there is a tendency to focus just on woodlands and trees.  Biodiversity needs all types of habitats to be preserved.  There are species that live only in woodlands, some live only in meadows or wetlands.  Some need more than one type of habitat - for example, some bird species feed on the insects and seeds in meadows but nest in wooded areas.  

One species we found in bloom in the meadow is the spotted knapweed (Centaurea maculosa).  This is a European native that can become a problem where it becomes established.  It is a biennial, which means it completes its entire lifecycle in two years.  The first year it is a rosette (group of leaves low to the ground) and its function is to photosynthesize and store nutrients in its large taproot.  Over the winter, the above-ground part of the plant dies back, but the roots go dormant and survive the winter.  The second year, it uses the stored energy in the taproot to produce flowers and fruit.  Once the fruit matures, it releases a large number of seeds and then the individual plant dies.  The large number of seeds it releases gives it an advantage over other plants. This is a plant I would recommend the Conservancy weed out of the Meadow.  But, as I've mentioned before, native or non, invasive or not, I can appreciate the beauty in all plants.  Just take a look at this flower. 

Centaurea maculosa Asteraceae

Obedient plant (Physostegia virginiana) is a fun one to observe.  This lovely inflorescence is made up of tubular, lipped flowers that look like little snapdragons.  But don't be fooled, it is in the mint family, not the snapdragon family.  The fun part comes in when you gently push each flower in any direction.  It will stay where you push it, as if it has a little hinge at the base of the flower.  (Note to self: make some fun videos to include in the blog!)  This North American native is a perennial, so unlike the Centaurea, it will continue to live for more than two years.  Every winter, the above-ground parts die, the roots stay dormant and the plant re-emerges in the spring.  The total number of years a perennial lives varies with each species.  Herbaceous perennials may live from several years to several decades.  Woody perennials (trees and shrubs) might live for hundreds of years.  

Physostegia virginiana  Lamiaceae

Physostegia virginiana Lamiaceae

I have written about sumacs in previous posts.  Here is another species in the same genus - shining sumac (Rhus coppalinum). The photo below shows you how it got its common name.  The flower is an inflorescence made up of tiny greenish-yellow flowers which turn into the easily recognized red fruit of the sumacs.  Visit the meadow in the fall to see the brilliant red fall color of this native shrub.

Rhus coppalinum Anacardiaceae

Rhus coppalinum Anacardiaceae

Rhus coppalinum Anacardiaceae

Oaks (Quercus sp.) have easily recognizable leaves and fruit (acorns).  But learning to distinguish all the different oak species is not as easy.  In my July 22 entry, I mentioned a white oak (Q. alba) we found.  That is more likely a swamp white oak (Q. bicolor).  Daniel and I will verify.  The photo below shows a common oak species found in Central Park, as well as throughout other City parks: the red oak (Q. rubra).  The lobes of red oak are bristle-tipped.  The acorn is round with a flat brown cap (it looks like it's wearing a little beret). The buds are reddish-brown and cone-shaped.  In the winter, when trees are bare of leaves, buds and persisting fruit are how we can identify species.

Quercus rubra Fagaceae

Quercus rubra Fagaceae

Quercus rubra   Fagaceae

Quercus rubra Fagaceae

Last Monday I did a short collecting day in the Ramble.  Sweet pepper bush (Clethra alnifolia) is blooming and the fragrance is just intoxicating.  One of the sweetest smelling flowers we have, it is a good nectar plant to attract butterflies.  It is native to eastern United States and grows in moist to wet soil.  This species tends to reproduce by suckering, that is, new plants are produced from root tissue.  Since this type of reproduction does not depend on seeds, it is called asexual reproduction (also called vegetative reproduction).  The new plants will be genetically identical to the parent plant (clones).  The sumacs we have been looking at in these blog posts also reproduce by this method.

Clethra alnifolia Clethraceae

Clethra alnifolia Clethraceae

Colt's foot (Tussilago farfara) is an interesting member of the Aster family.  It is a perennial which spreads by seeds and rhizomes (underground horizontal stem of a plant).  The flowers resemble dandelions and emerge in the spring before the leaves.  This species has not been documented before as being in Central Park.  I remember seeing it some years ago, but only a small group by the Loch.  Daniel and I recorded it in the spring when we found it in flower by Glenspan Arch.  The group in the photo below is growing along the Lake just north or Bow Bridge.  It will be interesting to see if it is growing elsewhere in the Park.

Tussilago farfara Asteraceae

Ramble and Reservoir

I failed to write about our foray last week, so I will add it to today's post.  The 23rd was a short walk in the Ramble, not too many species seen.

The Oven is a nice birding spot in the Ramble just south-west of the Boathouse.  There is a beautiful rock outcrop on which one can stand and look into a swampy wooded area and see some of the many species of birds that live in and migrate through the Park.  We examined the plants growing in the cracks of the rocks and collected several specimens of the grass family (Poaceae).  

View from the "Oven" in the Ramble

Panic grass (Panicum sp.) and rosette grass (Dichanthelium sp.) are similar genera and used to both be classified as Panicum.  Like all grasses, they have hollow stems and joints along the stem. The mnemonic "sedges have edges, rushes are round, grasses have knees all the way to the ground" helps to remember this characteristic.

Gleason and Cronquist's Manual of Vascular Plants* lists 48 Panicum species for the Northeast.  This edition was written before Dicanthelium was split off.  Daniel and I have collected 14 specimens in these two genera. Tune in to future posts when we determine which species we have.  In the meantime, here is generally what the two genera look like.

Dichanthelium sp. Poaceae

Panicum sp. Poaceae

We collected arrowwood viburnum (Viburnum dentatum) already, but today we saw a nice stand of it in fruit. The viburnums are shrubs with opposite leaves.  Arrowwood is a native species with beautiful black fruit that is attractive to wildlife.  The fruit contains a high percentage of fat which is an important energy source for migrating birds.  It has always been a good restoration species for the Park as it grows easily and until recently had not serious pest problems.  But the viburnum leaf beetle (Pyrrhalta viburni) showed up in the Park within the last 10 years and some of the shrubs have shown signs of beetle damage.  Let's hope it does not decimate the populations of arrowwoods we have.  Viburnums were formerly classified in the honeysuckle family (Caprifoliaceae), but have been moved to the Adoxaceae. The specific epithet (the second part of the scientific name) "dentatum" refers to the toothed margins of the leaves.

Viburnum dentatum Adoxaceae

On the 30th we walked around the Reservoir. Daniel had seen a couple of species from prior lists but not yet collected by us and we have not seen those species elsewhere in the Park.  Conservancy staff helped us with plants that were out of our reach.  We are grateful to Maria Hernandez (Director of Horticulture), Bill Kearny (Reservoir Supervisor) and Andrea Gaskin (Reservoir Zone Gardener) for their help.  Ken Chaya and Marie Winn joined us today.

East side of the Reservoir

The plants on the reservoir wall are a mix of wild plants and plants that have been seeded in by Conservancy staff.  Woody material has to be kept off the wall to prevent damage, so herbaceous plants are encouraged to provide habitat for wildlife.

The first species we collected was lance-leaved coreopsis (Coreopsis lanceolata).  This species is native to central and southeastern United States, although it does just fine in our area.  This member of the aster family thrives in poor soil as long as there is good drainage.

Coreopsis lanceolata Asteraceae

Yellow sweet clover (Melilotus officinalis) is probably found elsewhere in the Park, but so far this is the only group we have come across.  It has yellow flowers and compound leaves that are typical of the bean family. A Eurasian species that seeds readily, it is considered invasive in some habitats.

Melilotus officinalis Fabaceae

We found a few other species along the path of the Reservoir.  The photo below is of bladder campion (Silene vulgaris).  Notice the balloon-like calyx.  The calyx is what the collection of sepals is called, the outermost structures in a flower.  There is a native campion (Silene stellata) that has a swollen calyx also, but can be distinguished because it has fringed petals.  The species we found has only small notches in the petals. 

Silene vulgaris Caryophyllaceae

There are 5 species of copperleaf listed in Gleason and Cronquist, we have found at least two of them. Today Daniel noticed a third growing along the Reservoir path.  This new record for Central Park was first documented in the Northeast by Thomas Delendick in 1990 (http://goo.gl/tYQEXq).  He found a few plants growing along the sidewalk in front of a brownstone in Park Slope, Brooklyn.  It has since spread to all five boroughs and beyond.  (http://goo.gl/JX0nx1).  Acalypha australis. We will have to keep an eye out to see how common it is in the Park.

Acalypha australis Euphorbiaceae

In my post about the 79th Street transverse road, I spoke about the far eastern smartweed, Persicaria extremiorientalis.  There is a large, robust stand of it growing at the north end of the Reservoir.

Persicaria extremiorientalis Polygonaceae

Finally, I will leave you with a photo of a common plant we have already seen in these blog posts, common milkweed (Asclepias syriaca).  Part of what is fun about this project is looking for new and interesting plants, but I have to say, I never get tired of the common species.  This is a beauty of a native, important host plant for the Monarch butterfly caterpillar and that seed pod is just spectacular.  Look closely and you will see a small lady-beetle, probably feeding on aphids which are feeding on the sap of the milkweed.  Ordinary is not necessarily dull.

Asclepias syriaca Asclepiadaceae

*Manual of Vacular Plants of Northeastern United States and Adjacent Canada, second edition by Henry A. Gleason and Arthur Cronquist, published by the New York Botanical Garden, 1991.


96th Street

Today was a short day of collecting, but it was a lot of fun. We had the pleasure of having my friend Marie Winn with us today.  I met Marie when I first started as a gardener for the Conservancy many years ago. You may know her, she is the author of two books about Central Park - Red Tails In Love: Pale Male's Story - A True Wildlife Drama in Central Park and Central Park in the Dark: More Mysteries of Urban Wildlife.  She also has a nice website where she talks about nature in Central Park (www.mariewinn.com).  I met her and many other birders back in 1994 when Pale Male, the famous red-tailed hawk, started nesting on Fifth Avenue.  I used to join Marie on her early morning bird walks and learned a great deal from her and the other birders. It was great to have her along today and feel like I was returning the favor of teaching!

Daniel Atha and Marie Winn

Another treat today was that we found several species that have not been previously documented for Central Park.  Now this does not mean folks don't know it is here, just that in previous inventories, no one documented it.  It may have been overlooked or it may in fact be a new species for the park.  Wind, birds, people, we all move plants and plant seeds around, so it is possible for new species to show up in the Park. The Conservancy plants many native species for restoration projects and some of these have begun to regenerate on their own, so these would not have been on previous surveys and would be listed as new for the Park in our survey.

At the entrance to 96th Street and Central Park West, we found a nice stand of smooth sumac (Rhus glabra).  In my last blog entry (July 16) I spoke about staghorn sumac.  This plant looks very similar and has a similar growth habit.  They both exude a white latex.  However, smooth sumac does not have the hairy stems.  This is a species that the Conservancy has planted in restoration projects and it is reproducing nicely.

Rhus glabra Anacardiaceae

Smooth stem of Rhus glabra Anacardiaceae

White latex of Rhus glabra Anacardiaceae

On the transverse overpass, still at the 96th Street entrance, we collected a specimen from a white oak (Quercus alba).  This is not on any previous list.  Most white oaks in the park look like they were planted and probably were, but this one looks spontaneous.  It seems to be around 40 or 50 years old and is in a spot where no one would logically plant a tree - on the edge of the path near the transverse road.  We will have to be observant and see if we find more spontaneous white oaks around.

Quercus alba Fagaceae

Grasses, sedges are rushes are difficult groups to identify.  Previous lists do not have many species listed in these groups, most likely because of identification issues.  This is the advantage of making herbarium specimens of each species we find.  If we can't figure it out, there will be someone that can and we will have a permanent sample to use for identification.  It may take time, but it will happen.  

On the east side of the West Drive at 96th Street, we found two rushes growing near each other.  One is the common path rush (Juncus tenuis).  The other we do not have an identification for yet.  Stay tuned...

Juncus sp. Juncaceae

On the fence-line at the Tennis House, we found a vine climbing.  It had just been weed-whacked by staff trimming the growth along the fence, but we got it in time to make a pressing.  It is a common morning glory (Ipomoea purpurea).  A very common ornamental that people use in their gardens and that spreads readily from seed.

Ipomoea purpurea Convolvulaceae

Caught it just in time to make a pressing.  Ipomoea purpurea Convolvulaceae

Today we got only a handful of new species for our project, but they were interesting species.  And the company was wonderful.  Ken Chaya also joined us for a bit.  The four of us enjoyed each other's company and learned a lot from one another.




Reservoir on a Rainy Day

Today the rain cut our day a bit short, but we managed to find a few good species.  We entered the Park at West 86th Street aiming to walk around the Reservoir.  Daniel had spotted butter-and-eggs (Linaria vulgaris) while on his morning run so we knew we wanted to catch it while it was in flower.  

Our first plant of the day was Sycamore maple (Acer pseudoplatanus).  Sycamore maple is a Eurasian species that is invasive our region.  However, in Central Park, it is not as invasive as the Norway maple (A. platanoides).  It requires moist soil and many have not survived several summer droughts in past years. Sycamore maple leaves are a very dark green with red petioles (leaf stalks).

Acer pseudoplatanus Aceraceae

On the south side of the reservoir there are many areas that have been planted with native plants by the Conservancy.  Bee balm (Monarda fistulosa) is one that is now spreading nicely on its own.  It is a perennial with a square stem, which is typical of the mint family (Lamiaceae) and the light green leaves are wonderfully fragrant.  Sometimes if you look closely at plants, you can find unexpected beauty.  The stigmas (female organ) of the bee balm are feathery and delightful to look at.

Monarda fistulosa Lamiaceae

Monarda fistulosa Lamiaceae

As we rounded to the east side we found a vine growing in one of the plant beds.  We knew it was in the Gourd family (Curcurbitaceae), the family that includes melons, squash, pumpkins and zucchini.  With help from Tom Andres, a curcurbit specialist, the plant was determined to be a melon (Cucumis melo), the cantaloupe or honeydew.  We will revisit the site and if it has not been weeded out of the planting bed, we can see what it will become.

Cucumis melo Curcurbitaceae

Cucumis melo Curcurbitaceae

Dogbane (Apocynum cannabinum) is a species we have already collected, but we found a some plants full of fruit and I thought it deserved to be shown off.  The specific epithet "cannabinum" refers to this plant's similarity to marijuana (Cannabis sativa) not as a drug, but as a source of fiber.

Apocynum cannabinum Apocynaceae

Further along there was a beautiful specimen of wild lettuce (Lactuca canadensis).  A tall plant, this specimen was over six feet tall, with beautiful deeply lobed leaves and an inflorescence with many small flowers in different stages, some flowering, some fruiting.  Most people consider the wild lettuces weeds, but some are native and they belong in our open sunny fields.

Lactuca canadensis Asteraceae

Lactuca canadensis Asteraceae

We finally made it to our stand of butter-and-eggs (Linaria vulgaris).  And a beautiful stand it was.  A Eurasian species, it is a common perennial in North America, often found in sunny, disturbed locations.  If you look at the individual flowers, you'll see they are similar to snapdragon flowers and in fact the two species are in the same family (Scrophulariaceae).  Butter-and-eggs is an example of a garden plant that has escaped cultivation and has become a permanent part of our flora.

Linaria vulgaris Scrophulariaceae

Linaria vulgaris Scrophulariaceae

Along the bridle trail around 94th Street there is a beautiful stand of staghorn sumac (Rhus typhina).  We've collected this one before, but it is worth looking at again.  The red inflorescence (cluster of flowers) is distinctive, making it easy to identify as a sumac, as do the very large compound leaves.  The dense hairs on the stems tell us it is staghorn sumac (compare with the stem of smooth sumac above).

Rhus typhina Anacardiaceae

Rhus typhina Anacardiaceae

Rhus typhina Anacardiaceae

Rhus typina Anacardiaceae

Our final plant of the day is a common perennial seen throughout the City during the summer.  Just look in sunny places for a pale blue flower, leaves that look like dandelion leaves and you have found chicory (Cichorium intybus).  Here is another moment to take out your hand lens and look at the details of the flower, you will be treated to some interesting shapes.  A non-native that is invasive in some areas, it is a beautiful plant.

Cichorium intybus Asteraceae

Cichorium intybus Asteraceae

Turtle Pond and Great Lawn

Having worked for the Conservancy for 19 years, I did my fair share of planting.  It is wonderful to see the species we have used for restoration spreading on their own.  Soil throughout the Park used to be so compacted that there was not much regeneration.  On the south shoreline of Turtle Pond there are several large redbuds (Cercis canadensis) that were probably planted during the 1997 restoration of the area.  If you look around, you can see seedlings popping up in many places.   The distinctive heart- shaped leaves make this tree easy to identify and if you remember back to earlier this spring, they have fantastic fuchsia-colored flowers.  

Cercis canadensis Fabaceae

Redbud seedlings

Last week we went looking specifically for ferns.  Today we found one species of fern that has been planted for restoration purposes and has begun to spread on its own.   
Ostrich fern (Matteuccia struthiopteris) is a colony-forming fern and grows in a beautiful vase shape.  This species is dimorphic – the fertile fronds look different from the sterile fronds.  They are shorter, and when ripe have brown tissue covering the sporangia (see the June 30 blog entry). This fertile frond can persist throughout the winter and is very attractive in the snow.  The photo below shows a fertile frond still green, before it is fully ripened.  The second photo showing the colony-forming habit was taken in the Shakespeare Garden. 

TMatteuccia struthiopteris  Onocleaceae

Ostrich fern fertile frond

Matteuccia struthiopteris Onocleaceae

At the Castle, along one of the pipe rail fences, we found bouncing-bet (Saponaria officinalis).  Another common name of this plant is soapwort, the name Saponaria comes from the Latin meaning soap.  It contains a toxic substance called saponin that lathers up when shaken with water.  Used externally and diluted, it has traditionally been used as soap.

Saponaria officinalis Caryophyllaceae

Crown-vetch (Securigera varia) is a perennial in the bean family (Fabaceae) that forms a dense groundcover. It is native to Europe, Asia and Africa and is considered invasive here.  It has a dainty pink flower but it is a tough little plant, growing strongly with little to no maintenance.  We found this stand growing along the fence line north of the Great Lawn along the inside of the 86th street transverse.

Securigera varia Fabaceae

Securigera varia Fabaceae

Also along the transverse but closer to the East drive, we found two plantain species (Plantago sp.) growing together. Another opportunity to compare species of the same genus, side by side.  There are three species in this genus that are common in our area.   The two shown below are often misidentified as one species because they resemble each other closely.  Broadleaf plantain (Plantago major) is a Eurasian species and Pale plantain (Plantago rugelii) is native to North America.  At first glance they look alike, but examine the leaves.  The base of the petioles (leaf stem) of the Pale plantain will be reddish or purplish.  Compare the ripe fruit with a hand lens, the capsules of the pale plantain will be longer and narrower than that of the broadleaf plantain.   The third species (not shown here) is the English plantain (Plantago lanceolata).

Plantago rugelii Plantaginaceae

Plantago major Plantaginaceae

Plantago major Plantaginaceae

Our final plant of the day is a little non-native biennial plant that is growing around the Still Hunt statue on the east side of the Ramble.  Honesty (Lunaria annua) is in the Mustard family (Brassicaceae), but the fruit does not look like the typical pods of a mustard.  The fruit also gives this plant its other common names – money plant and silver dollar.  Gardeners love to plant this, not only for its bright flowers, but also for the seed-heads which can be dried and added to flower arrangements.  The second photo was taken back in May.  I have seen it in this spot for many years and it is spreading, although it spreads very slowly.

Lunaria annua Brassicaceae

Lunaria annua Brassicaceae

79th Street Transverse Road

Today’s foray took us into the 79th Street transverse road.  I am so grateful these tranverse roads were part of the design of the Park.  Can you imagine our park being crossed by that traffic all day?  There are sidewalks for pedestrians to use, but I don’t recommend it; much nicer to walk through the Park itself, especially on such a hot humid day as today.  Breathing in the pollution from the cars is not pleasant.  Despite this, we found some good plants today.

79 Street Transverse Road

We found a small yew shrub (Taxus baccata) growing on the wall along the north side of the transverse.  This shrub is widely planted throughout the park, but does not usually reproduce on its own.  This is only the third young one we found that appears to be spontaneous. 

Taxus baccata Taxaceae

We found two species of Amaranth.  Finding examples of a genus growing together gives you a chance to look at similar characteristics and differences that separate them into individual species.  Both species are annuals and have greenish flowers.  Amaranthus blitum is easily identifiable by the notch on the ends of each leaf.

Amaranthus blitus Amaranthaceae

Amaranthus albus Amaranthaceae

Next we found two species of sow thistles (Sonchus sp.).  Both exude a white latex when cut.  One has leaves that clasp the stem, the other prominent hairs.  These are members of the Aster family (Asteraceae).

Sonchus asper Asteraceae

Sonchus oleraceus Asteraceae

Sonchus oleraceus Asteraceae

The knotweed family (Polygonaceae) has many representatives in Central Park and we found several today.  There was plenty of Japanese knotweed (Fallopia japonica), an invasive species found throughout the park.   The plant grows to be very large with stems that look like bamboo, but with the distinctive red swollen joints covered with a sheath (ocrea) that is a defining characteristic of the knotweed family. 

Fallopia japonica Polygonaceae

Ocrea - sheath at node typical of Polygonaceae

But is it Japanese knotweed or is it giant knotweed (Fallopia sachalinense)? On our May 3 foray along the north end of the Park, Daniel taught me to distinguish the two species.  Often mistaken for Japanese knotweed and often growing alongside it, giant knotweed does in fact look similar, but look more closely.  The leaves have distinctly different shapes.  One is heart shaped, the other blunt.  Of course, to be classified as different species, there has to be a difference in the flowers and fruit, which there is.  But this leaf characteristic is consistent in each species, so it is an easy way to tell them apart when there are no flowers or fruit to examine.

Fallopia sachalinense Polygonaceae

Fallopia japonica Polygonaceae

There are two species of knotweed vines growing along the transverse.  Russian fleece vine (Fallopia baldschuanica) and Climbing buckwheat (Fallopia scandens)

Fallopia baldschuanica Polygonaceae

Fallopia baldschuanica Polygonaceae

Fallopia scandens Polygonaceae

Fallopia scandens Polygonaceae

A common knotweed that is often misidentified is the Far Eastern smartweed (Persicaria extremiorientalis).  A large, robust smartweed, this species went undetected in the flora until Daniel identified a specimen and scoured through herbarium specimens to find others.  He discovered that it was first documented in Brooklyn and Queens in 1961, but those specimens and all others thereafter were misidentified.  The robustness of this plant and the hairy stems are two characteristics that indicate you are looking at Far Eastern smartweed.

Persicaria extremiorientalis Polygonaceae

Toward the east side, on the north side of the transverse, there is a nice stand of dock.  This genus (Rumex) can be seen throughout the park, with its tall stems of seeds that turn brownish.  Many people don’t find this plant attractive, but if you look closely, each of those seeds is quite beautiful.  Here is a close up of curly dock (Rumex crispus) that we found on June 30 along 110 Street and the West drive.

Rumex crispus Polygonaceae

Today’s find is called Patience dock (Rumex patietia).  An attractive plant, its leaves are not crinkled like the curly dock.  We have so far only found this species here on the 79th Street transverse.  This is the first botanical collection of this plant for Central Park and for New York County.  It is always a bit of a thrill to be the first to document something.  It does not mean this plant has not been around,  just that no one identified and recorded it.  But that is the point of this project, to know what we have and document it so that in the future we can see what changes have occurred in the flora of the Park.

Rumex patientia Polygonaceae

North End Ferns

Today’s objective was to collect ferns from the rock outcrops along 110 Street.  This is a beautiful area, part of what was a late add-on to the original park design.  Originally, the Park only went up to 106 Street. Olmsted and Vaux wanted the rugged wild-looking area from 106th to 110th Streets and eventually made it part of the Park.  We are lucky they did or we would not have the Great Hill, North Woods and Meer!

West Drive 109th Street

Historic records show at least 18 species of ferns grew in Central Park.  Most have been extirpated (gone locally extinct).  A few lingered on through the years and some are making a comeback due to restoration efforts.  As you walk along the drive, you see many nooks and crannies out of which are growing all sorts of plants.  Fern spores easily fall into these crevices and since there is often shade and moisture, they grow quite well.  We found several species growing in this area. 

Some ferns, such as sensitive fern (Onoclea sensibilis), are easy to identify.  The large, coarse fronds (leaves) are bright yellow-green and somewhat triangular in shape.  This fern grows in moist soil in part to full shade.  Control of invasive species and restoration of compacted soil has helped this species spread throughout the Park, especially in the woodlands.

Onoclea sensibilis Onocleaceae

Onoclea sensibilis Onocleaceae

For ferns that are not so easy to identify, you have to look to the spores.  Spores are how ferns reproduce and disperse.  They are tiny, dust-like particles that can survive harsh conditions and germinate when conditions are favorable.  They occur in two different ways on ferns – on the back of a frond, or on a separate, highly-modified frond, called a sporangiophore.  When spores are present, we call it a fertile frond.

The Sensitive fern has its spores on separate fertile fronds.  These fertile fronds give the plant its other common name, bead fern.  Ok, some more fun botany terminology: spores are formed in structures called sporangia and sporangia are clustered into structures called sori.  For this species, the sori are the bead-like structures we are seeing on the fertile frond.  Patterns of sori are a main character we use to identify species of ferns.

Fertile frond of sensitive fern

Next we found ebony spleenwort (Asplenium platynueron).  It is also a very recognizable fern, but if you are not sure, turn the frond over and if it is fertile, you will see the sori.  Check your fern field guide and match the pattern.  In this case, the sori form two lines that resemble a row of chevrons along the back of the frond.  This fern can be found growing on the rock outcrops as well as the perimeter and Blockhouse walls.

Sori of Asplenium platyneuron Aspleniaceae

Asplenium platyneuron Aspleniaceae

Asplenium platyneuron Aspleniaceae

Asplenium platyneuron Aspleniaceae

  Blunt-lobed cliff fern (Woodsia obtusa) is a small fern species that has survived through the years of the Park’s history.  It can be found growing on rock outcrops as well as on the Blockhouse and perimeter walls.

Sori of Woodsia obtusa Woodsiaceae

     We also found hayscented fern (Dennstaedtia punctilubula) in this area.  This is a species that the Conservancy has been using in restoration projects and it has begun to spread nicely.   The common name of this fern comes from the scent given off when you crush a frond.  Hayscented ferns have very small round sori on the backs of the leaves (not shown).  The photo below shows a lovely bed of this fern in the Shakespeare Garden.

Dennstaedtia punctilobula Dennstaedtiaceae

We came across a couple of species of other plants common in the park, but with structures that are often overlooked.  The very abundant field garlic (Allium vineale) was in flower.  This plant, however, has tiny aerial bulbils and very few flowers.  Like onions, field garlic grows from an underground bulb.  Bulbils are just what they sound like – small bulbs – and in this case they occur above-ground.  These bulbils are how the plant reproduces, the structure breaks apart dispersing the bulbils.  Sometimes these bulbils sprout and begin to grow before falling off the parent plant (second photo).

Allium vineale Liliaceae

Allium vineale Liliaceae

The other somewhat common plant with an interesting structure was the Osage-orange (Maclura pomifera) we came across at the northeast corner of the North woods.  If you do not know the Osage-orange, you should look for it this fall.  It has a very interesting fruit.  The tree is in the Mulberry family, but the fruit looks nothing like the mulberries we like to eat.  It is a large sphere, around 3-6 inches in diameter and bright yellow-green.  The tree itself is easily confused with a mulberry, both having orange inner bark and glossy green leaves.  However, the Osage-orange has thorns and mulberries do not.

Maclura pomifera Moraceae

Maclura pomifera Moraceae

Maclura pomifera Moraceae

The structure shown below is a fruit fallen from the tree prematurely.  It is much smaller than it would have become at maturity, and the “hairs” you see are the stigma and styles of the many flowers that made up the female inflorescence (cluster of flowers).

Maclura pomifera Moraceae

Each day we see so many good species, it is hard to include them all here.  I will share more on our next day of collection.  For now I will leave you with a non-plant organism that has made a nice comeback in Central Park, the Eastern chipmunk (Tamias striatus).  He was busy stuffing his little cheeks with food and he didn’t seem to mind us working near him.

Tamias striatus

South End

Today we walked through the south end of the Park – along the 66 street transverse, Heckscher Ballfields area, Chess and Checkers and the Pond.  We were accompanied by Ella Baron.  Ella manages a botanical garden in Belize and wanted to learn more about making plant collections.  Also with us were Jason Leggett and Jay Wen who are working on developing a BioBlitz-type workshop at Kingsborough Community College.

Ella and Daniel

At the Carousel, we found this pretty little orchid in bloom.  Broad-leaved helleborine (Epipactis helleborine) is the only wild orchid that grows in the Park anymore.  Unfortunately, it is not one of our native orchids and it is considered invasive in some areas.  Historical records show at least two species of native orchids that have been extirpated in Central Park – rattlesnake plantain (Goodyera pubescens) and slender ladies’-tresses (Spiranthes lacera ).   Most people associate orchids with the tropics and don’t realize they grow in our area.  New York State has approximately 60 species of native orchids, some of which are common although most are rare.

Epipactis helleborine Orchidaceae

Also at the Carousel, we saw redbud (Cercis canadensis) in fruit.  These pods give us a hint that this tree is in the bean family (Fabaceae).   Here we see a feature that is not common in northern plants – cauliflory.  The flowers and the fruit form on the woody parts of the plant rather than the soft, herbaceous parts.  The photo of the blooms was taken at the Great Hill back in April.

Cercis canadensis Fabaceae

Cercis canadensis Fabaceae

On the wall of Dalehead Arch at West 64 street we found several Clasping Venus’ Looking Glass (Triodanis perfoliata), a North American native annual.  It is often found in weedy sites with poor soil, an adaptation that allows it to survive in small crevices in a bridge wall.

Triodanis perfoliata Campanulaceae

Triodanis perfoliata Campanulaceae

At the Pond, on the North side of Gapstow Bridge are a few small stands of Purple loosestrife (Lythrum salicaria).  This plant is a Eurasian perennial introduced into many areas of temperate climate, probably as an ornamental since it is very lovely.  However, it is an invasive plant that has become a problem in many of our wetlands.  It is a prolific seeder and can spread rapidly, disrupting the flow of rivers and sharply reducing biodiversity by crowding out our native species.  Reductions in plant biodiversity leads to reduced food and cover species that other organisms depend on and in this way reduce overall biodiversity.

Lythrum salicaria Lythraceae

Cattails (Typha sp., Typhaceae) are native wetland plants that can be found at the Pond and are easy to identify. The plant can reach heights of 3-6 feet with brown sausage-shaped flowers and fruit.  The male and female flowers are separate, as can be seen in the photo below.  Actually, this is more properly called an inflorescence since it is made up of many small flowers.  The male flowers occupy the top portion and are lighter in color.  If you look closely you will see many tiny stamens each producing pollen. Once the pollen is released, the male flowers wither and fall off.  The female flowers are the lower part of the inflorescence and it is this part that develops into the fruit.  The seeds are dispersed by white fluff carried away by the wind similar to how a dandelion disperses its seeds.  Some bird species use this fluff to line their nests.

Typha sp. Typhaceae

Typha inflorescence

Another beautiful native we found along the shore was Jewelweed (Impatiens capensis).  Jewelweed is an annual plant native to North America.  The stems and leaves are somewhat translucent and succulent.  There are several large stands of this plant throughout the park, especially in the woodlands.  If you seek them out, you may be lucky enough to see hummingbirds feeding on the small orange flowers.  One of my favorite things about this plant is its seed dispersal mechanism.  It uses what is known as mechanical dispersal.  The tissue protecting the seed is sensitive to touch and if you brush against it, it springs open and the seed is catapulted several feet away from the mother plant.  This gives rise to the plant’s other common name, Touch-me-not.

Impatiens capensis Balsaminaceae

We ended the day with a bit of a mystery that we hoped would be a rare plant find.  Amongst a stand of Sensitive fern (Onoclea sensiblis) on the south side of the Pond, Daniel spotted a small fern that looked different from the rest.  Thinking we may have stumbled upon a rare find and not wanting to collect a specimen because it was the sole individual, he sent a photo to his colleague, Robbin Moran, fern expert at the New York Botanical Garden.  Robbin was excited about the photo, but for a different reason.  Robbin determined that the leaf is not a rare species, but is a rare leaf form of the Sensitive fern, intermediate between the fertile and sterile leaves. No rare find for us today.

Onoclea sensibilis Onocleaceae



West side and Ramble

Daniel and I started our day at 77 Street and Central Park West by the Humboldt Statue and by one of the more impressive American elms (Ulmus americana) in the park.

Ulmus americana Ulmaceae

Our first plant of the day was collected reluctantly, a beautiful little purslane (Portulaca oleracea), growing along the base of a stone wall probably visited by every dog that enters the park here.  But with no other specimens around, science wins and Daniel made the collection. 

Portulaca oleracea Portulacaceae

Along the path to the Triplet’s Bridge in the Naturalist Walk area, we found a knotweed (Persicaria filiformis),  aka Antenoron filiforme, with robust leaves adorned with striking chevrons.  This is a cultivar, derived from the Asian sister of our American species, jumpseed (Persicaria virginiana). The Asian and American species are very closely related and sometimes lumped into one species, the two sometimes distinguished merely as varieties, subspecies or even forms of one another.

We didn’t collect much else in this area, but it is a lovely spot to visit, featuring a small brook, a wooden bridge and some beautiful shade to enjoy on a hot summer’s day.

Persicaria filiformis Polygonaceae

Persicaria filiformis Portulacaceae

A secluded little area behind the Yard yielded a few species, including a, St. John’s Wort (Hypericum perforatum).  Considered a weed by some, this beauty is a medicinal herb used to treat depression.

Hypericum perforatum Hypericaceae

We also found one of my favorites, butterfly weed (Asclepias tuberosa) with its bright orange flowers.  It is one of the milkweeds and as such, a host for Monarch caterpillars.  This species has been planted by the Conservancy as part of their on-going restoration of native species.  It has slowly begun to establish itself. 

Asclepias tuberosa Asclepiadaceae

We had lunch sitting on a bench just south of the Yard, enjoying the intoxicating fragrance of all the linden (Tilia) trees in bloom.  We were joined by Ken Chaya, co-creator of Central Park Entire, the beautiful map that depicts all the trees of the park (http://www.centralparknature.com/).

After lunch we walked through the Ramble and just west of the Maintenance shed we found another milkweed, this time the common milkweed (Asclepias syriaca).  Milkweeds all have white latex that oozes out of any cut on the plant tissue.  It is a toxic chemical the plant produces to protect itself from herbivores.  The Monarch caterpillar is the only one that not only survives the toxin, but sequesters the chemical in its tissues, making the caterpillar and butterfly toxic to predators such as birds.  

Asclepias syriaca Asclepiadaceae

Asclepias syriaca Asclepiadaceae

Asclepias latex

Down the hill from the Delacorte Theater, I have for years watched a tiny patch of whorled loosestrife (Lysimachia quadrifolia) struggle to survive and reproduce.  One plant became two, then two became a few.  I told Daniel we should go look and see if there was enough to make a collection.  We didn’t make it to that spot, but instead, stumbled upon this magnificent stand of this species in the Ramble.  It seems Conservancy staff planted a few groups and they are reproducing very nicely.  What a beautiful find!

Lysimachia quadrifolia Myrsinaceae

Some days it feels like we can never get out of the Park.  We attempt to leave, but find one more plant and then one more plant.  We found the loosestrife as we were attempting to leave.  As we were packing up to try again, Ken mentioned to Daniel that the largest Amelanchiers (shadbushes) in the park were just a little way from where we were standing.  Of course, he had to see.  I don’t blame him, I have admired these trees for years.  These trees are over 10 meters tall with beautifully striated trunks.  If you have not seen mature Amelanchier in the wild, you can easily walk by these and not realize what they are. 

Amelanchier sp. Rosaceae

Amelanchier sp. Rosaceae