[APWG] Wavyleaf Basketgrass Moves in Waves through Maryland Forests

Wed Oct 10 06:39:33 CDT 2007

Wavyleaf Basketgrass Moves in Waves through Maryland Forests
Have You  Seen It?

A spreading invader -- everything on the ground plane is wavyleaf, photo by
Kerrie Kyde

Attention Citizen Scientists!
Help Control Wavyleaf Basketgrass
If you have seen this NEW and Highly Invasive Species,
Report Your Sightings <mailto:kkyde at dnr.state.md.us> 

Typical growth habit of wavyleaf basketgrass, photo by John SnitzerTwo small
populations of a Eurasian grass never previously found in the US were
discovered in Patapsco State Park by sharp-eyed botanists in 1996.
Smithsonian Institution and international experts confirmed its identity as
an exotic subspecies of a grass that is native to sub-tropical and tropical
regions, including the southeastern coast of the US.  

The native grasses are Basketgrass (Oplismenus hirtellus) and its related
native subspecies Bristle Basketgrass (Oplismenus hirtellus ssp. setarius).
The exotic subspecies is Wavyleaf basketgrass (Oplismenus hirtellus ssp.
undulatifolius).

In 2000, a private consulting ecologist found this grass by a wooded stream
on the property of the Hernwood Landfill in Baltimore County.  Last year
this shade-tolerant moist forest grass turned up more than 20 miles away in
Little Paint Branch Park in Prince George’s County, where is it being
actively removed by groups of volunteers.  During this dry summer, this
fast-moving grass was one of the few plants obvious on the forest floor, and
now that fall has arrived, it is blooming and producing seed.

Wavyleaf basketgrass is a striking grass. It is a low-lying, trailing
perennial grass, branching and rooting at nodes along creeping stems called
stolons.  The leaf blades are flat, about ½ to 1" wide and between 1½ and 4”
long, deep green with rippling waves across the grass blades, as though the
tide were coming into shore along the leaves. They have elongated pointed
tips. The leaf sheaths and stems are noticeably hairy, although the hairs
are very short. This characteristic distinguishes it from its closest
relative Oplismenus hirtellus ssp. setarius, which occurs naturally in the
southeastern US and Mexico and has only a few hairs, if any.  When it
blooms, in late September and into October, the grass spikelets have glumes
(lower bracts) with very long awns (extended pointed tips).  The awns
produce a sticky substance that allows the grass seed to adhere to passing
animals and so disperse.

Foliage of Wavyleaf basketgrass, photo by Kerrie Kyde

A group of Oplsimenus flowers (inflorescence) showing the sticky purplish
awns that help distribute the seeds

If you walk, run, bicycle, horseback ride or pass through a patch of this
grass right now, 
the seeds will stick to your pants, boots and vehicle and can be moved to
new 
uninvaded locations (see photo below).  Please take precautions.

Photo of Wavyleaf basketgrass sticky awns, photo by John SnitzerIt is
unclear how Wavyleaf basketgrass first came to the US and to Maryland,
although it is possible that the Baltimore County landfill was the unwitting
source of the natural area infestation, spreading from hanging basket
plantings that someone threw away.  Variegated varieties of the related O.
hirtellus ‘Variegatus’ are sold ornamentally as “Ribbon grass” or “Basket
grass,” but the wavyleaf subspecies does not seem to be sold in the
horticultural trade. It does appear to spread rapidly through wooded natural
areas: the Little Paint Branch pockets of infestation add up to about 3
acres, and in sections of Patapsco Valley State Park, the grass covers more
than 150 acres.

DNR has begun to map the extent of the infestation, and is taking steps to
limit the spread of this invasive grass. If you hike, bike, horseback ride,
or simply walk your dog in Maryland forests, especially in moist forests
along waterways, please keep an eye out for this grass. If you think you
have seen it, please let us know where and how much of it there is (a few
plants, patches, groundcover carpets).  Digital pictures, especially
close-ups, of the plant are extremely helpful for identification purposes. 

Photographs courtesy of Kerrie Kyde and John Snitzer
(top to botom):

*	A spreading invader -- everything on the ground plane is wavyleaf
basketgrass
*	Typical growth habit of wavyleaf basketgrass
*	Wavyleaf basketgrass foliage
*	A group of Oplsimenus flowers (inflorescence) showing the sticky
purplish awns that help distribute the seeds
*	A built-in distribution system: a researcher's pant legs are covered
with awns and seeds

Attention Citizen Scientists!
Help Control Wavyleaf Basketgrass
If you have seen this NEW and Highly Invasive Species,
Report Your Sightings <mailto:kkyde at dnr.state.md.us> 

For More Information 

For questions or comments, or if you have seen this grass, please contact: 

Kerrie Kyde, Invasive Plant Specialist 
kkyde at dnr.state.md.us

Phone: 410-260-8534 
You can reach us toll free in Maryland: 1-877-620-8DNR (8367)
TTY users dial 711

Department of Natural Resources
Wildlife and Heritage Service
580 Taylor Ave. E-1 
Annapolis, MD 21401 

This page up-dated October 01, 2007

www.dnr.state.md.us/wildlife/wl_basketgrass.asp

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