BugwoodWiki Article

Japanese stiltgrass
Microstegium vimineum (Trin.) A. Camus

Overview

Appearance

Microstegium vimineum is a delicate, sprawling, annual grass that is 0.5-3.5 ft. (0.2-1.1 m) in height. The stems can root at the nodes.

Foliage

The leaves are pale-green, alternate, lance-shaped, 1-3 in. (2.5-7.6 cm) long, asymmetrical with a shiny, off-center midrib. Upper and lower leaf surface is slightly pubescent. A silvery line runs down the center of the blade. Stems usually droop.

Flowers

Flowering begins in September, when delicate flower stalks develop in the axils of the leaves or at the top of the stems.

Fruit

Fruit is produced from late September through early October.

Ecological Threat

Most commonly a invader of forested floodplains, Microstegium vimineum is also found in ditches, forest edges, fields, and trails. It is very shade tolerant and can completely displace native vegetation. It is native to Asia and was accidentally introduced into North America sometime around 1920. It has previously been used as packing material for porcelain, possibly explaining its accidental introduction.

General Description

Microstegium vimineum is a shade tolerant, annual C4 grass (family Poaceae). It is a straggling or decumbent plant,usually 6-10 dm in height, and the reclining stems can grow up to 1.0 m (40 in) long. Its culms (stems) are typicallybranched, rooting at the lower nodes, and the nodes and internodes are smooth and hairless. The lanceolate leaf bladesare 5-8 cm long and 2-15 mm wide, sparsely pubescent on both surfaces, and distinctly tapered at both ends. Theligules are membranous, usually ciliate, and are 0.5-2.0 mm long.

The terminal or axillary inflorescence is a raceme, 2-7 cm long, with an elongate peduncle and an angled disarticulatingrachis. The hirsute fertile spikelets are deciduous, and occur in pairs, with one spikelet sessile and the other pedicellate. The glumes are equal in length (4.5-5.0 mm) and awnless. The first glume is flat and 2-3 veined. The second glume iskeeled and 3-veined. There are two lemmas per spikelet, with the lower one sterile and the upper, fertile one awnlessor often with a slender awn 4-8 mm. Both cleistogamous (flowers closed at pollination) and chasmogamous (flowersopen) conditions have been reported for M. vimineum in Japan, with the axillary flowers all being cleistogamous(Tanaka 1975, in Barden 1987).

The fruit or caryopsis (grain) of M. vimineum is yellowish to reddish, and ellipsoid (2.8-3.0 mm) in shape. Fruitingoccurs in September and October in North America.

Microstegium vimineum can be distinguished from other grasses by its thin, pale green, tapered leaf blades, and by its multiplespikelets that may be either terminal or arising from leaf axils. The alternate leaves have a silvery stripe of reflectivehairs down the middle of the upper leaf surface. In the fall, identification becomes somewhat easier after the plantdevelops a slight purplish tinge.

While M. vimineum is an annual, there has been some confusion regarding whether M. vimineum also occurs as arhizomatous, perennial (Mehrhoff 2000). According to Mehrhoff (2000), this confusion resulted whenspecimens of a native perennial, Leersia virginica, were incorrectly identified as M. vimineum. The annual M.vimineum can be distinguished from L. virginica (which it frequently grows alongside) by the former’s ciliate leaf sheathcollars and paired spikelets (versus L. virginica’s glabrous or pubescent leaf sheaths and 1-flowered spikelets).

Resources

Selected Images


0016158
0016158

Japanese stiltgrass
Microstegium vimineum
Plant(s)
James H. Miller & Ted Bodner
0016221
0016221

Japanese stiltgrass
Microstegium vimineum
Infestation
James H. Miller
1342060
1342060

Japanese stiltgrass
Microstegium vimineum
Infestation
Chris Evans
1378042
1378042

Japanese stiltgrass
Microstegium vimineum
Infestation
Chris Evans
1378045
1378045

Japanese stiltgrass
Microstegium vimineum
Infestation
Chris Evans
1378046
1378046

Japanese stiltgrass
Microstegium vimineum
Infestation
Chris Evans
2119021
2119021

Japanese stiltgrass
Microstegium vimineum
Plant(s)
Chris Evans
2154034
2154034

Japanese stiltgrass
Microstegium vimineum
Root(s)
Nancy Loewenstein
2308019
2308019

Japanese stiltgrass
Microstegium vimineum
Foliage
David J. Moorhead
2308026
2308026

Japanese stiltgrass
Microstegium vimineum
Infestation
Chuck Bargeron
2308028
2308028

Japanese stiltgrass
Microstegium vimineum
Foliage
Chuck Bargeron
5271065
5271065

Japanese stiltgrass
Microstegium vimineum
Flower(s)
Leslie J. Mehrhoff
5308018
5308018

Japanese stiltgrass
Microstegium vimineum
Plant(s)
USDA PLANTS Database
5308019
5308019

Japanese stiltgrass
Microstegium vimineum
Fruit(s)
Steve Hurst
5308020
5308020

Japanese stiltgrass
Microstegium vimineum
Plant(s)
USDA PLANTS Database

Maps


EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

EDDMapS Distribution

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List

Invasive Listing Sources

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Subclass: Commelinidae
Order: Cyperales
Family: Poaceae
Genus: Microstegium

Other System Links

Plants: MIVI
Bayer: MCGVM
GRIN: 316751
ITIS: 503829
NPDN Pest: PCAQBBA
NPDN Host: 36230

Synonyms and Other Names

Other Common Names:
Japanese stilt grass, Japanese grass, Mary's grass, Nepalgrass, basketgrass, microstegium, Nepalese browntop, Chinese packing grass

Related Scientific Names:

Andropogon vimineum (Trin.) A. Camus(Synonym)
Eulalia viminea (Trin.) A. Camus(Synonym)
Microstegium imberbe (Nees ex Steud) Tzvelev(Synonym)
Microstegium willdenowianum Nees(Synonym)
Pollinia imberbis Nees ex Steud(Synonym)
Pollinia viminea (Trin.) Merr.(Synonym)
Pollinia willdenowiana (Nees ex Lindl. ) Benth.(Synonym)

Categories

Category: Grass or Grasslike