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