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Oplismenus compositus (L.) P. Beauv.

Brief Summary

Comprehensive Description

    Oplismenus compositus
    provided by wikipedia

    Oplismenus compositus, the running mountaingrass, is a species of perennial plant from the family Poaceae that can be found throughout Asia (Pakistan[1] China), Africa, Australia, South America, Mexico[2] and Hawaii.[3]

    Description

    The plant is 15–150 centimetres (5.9–59.1 in) long. The leaves are lanceolate, ovate, are 2–16 centimetres (0.79–6.30 in) long and 8–35 millimetres (0.31–1.38 in) wide. It leaf blades are venated and have obscure cross veins with an apex which is acuminate or slightly acute. O. compositus have a raceme which is composed from inflorescence. It is borne on a side of central axis, is unilateral and is 2.5–11 centimetres (0.98–4.33 in) long. The central inflorescence axis 5–25 centimetres (2.0–9.8 in) long with angular rhachis and is either glabrous or pilose on the bottom. Spikelets come in 2 rows which are fertile, pedicelled, and sessile. The pedicels are oblong. The spikelets also have one basal sterile florets and one fertile florets while its rhachilla is not extended. They are 2.5–4 millimetres (0.098–0.157 in) in length and are lanceolate.[2]

    The glume is shorter than a spikelet and thinner than fertile lemma. It lower glume is ovate with its awn being 3–10 millimetres (0.12–0.39 in) in length. The upper glume is also ovate, but unlike the lower, is also herbaceous with glabrous surface which can be pubescent as well. It is also obtuse and is 0–4 millimetres (0.00–0.16 in) in length. Florets are 2–2.5 millimetres (0.079–0.098 in) in length and are pubescent, emarginate, and mucronate as well. Both florets and glumes are 1-keeled, but the veins are different; Glumes are 5 while florets are 7–11. The fruit is linear and is 0.5 millimetres (0.020 in) in length.[2]

    References

    1. ^ a b "Oplismenus compositus". Flora of Pakistan. Retrieved May 16, 2013..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
    2. ^ a b c W.D. Clayton; M. Vorontsova; K.T. Harman; H. Williamson. "Oplismenus compositus". The Board of Trustees, Royal Botanic Gardens. Kew: GrassBase. Retrieved May 15, 2013.
    3. ^ "Oplismenus compositus (L.) P. Beauv. Running Mountain Grass". USDA. PLANTS Profile. Retrieved May 15, 2013.

Distribution

Morphology

    Comments
    provided by eFloras
    This is a true forest grass and appears in gregarious patches in open shady places and in glades. The awns are sticky and the ripe spikelets become attached to passing animals, thereby distributing the seed.
    Description
    provided by eFloras
    Perennial. Culms stoloniferous, straggling, ascending to 20–80 cm. Leaf sheaths glabrous, pilose or tuberculate-hairy; leaf blades lanceolate to ovate-lanceolate, 3–20 × 0.5–3 cm, subglabrous to tuberculate-hairy, base usually oblique. Inflorescence axis 5–15 cm, glabrous to tuberculate-hairy; racemes 3–6, 2–6 cm, ascending to erect. Spikelets in 7–14 widely spaced, sometimes patent pairs, lanceolate, glabrous to thinly pilose; glumes herbaceous, awned, the awns stout, green or purple, viscid; lower glume awn 5–10 mm; upper glume awn to 3 mm or occasionally absent; lower lemma subcoriaceous, 7–9-veined, acute or with a stout 0.3–1 mm mucro; upper lemma subcoriaceous, ca. 2.5 mm, smooth. Fl. and fr. Sep–Nov. 2n = 54, 72*.
    Description
    provided by eFloras
    Perennial with rambling culms 15-150 cm long. Leaf-blades narrowly lanceolate to narrowly ovate, 2-15 cm long, 8-25 mm wide. Inflorescence 5-25 cm long, the lowest raceme 2.5-10 cm long, its rhachis glabrous to loosely pilose, the spikelet pairs ± distant. Spikelets lanceolate, 2.5-4 mm long, glabrous to pubescent; glumes with smooth viscid awns, the longest in each pair of spikelets 3-10 mm.
    Elevation Range
    provided by eFloras
    300-2800 m
    Physical Description
    provided by USDA PLANTS text
    Perennials, Terrestrial, not aquatic, Stems trailing, spreading or prostrate, Stems nodes swollen or brittle, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems mat or turf forming, Stems terete, round in cross section, or polygonal, Stems branching above base or distally at nodes, Stem nodes bearded or hairy, Stem internodes solid or spongy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath hairy, hispid or prickly, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades very short, 0.5-2 cm long, Leaf blades linear, Leaf blades lanceolate, Leaves with distinct crossveins, net-like transverse veins, Leaf blades 2-10 mm wide, Leaf blades 1-2 cm wide, Leaf blades 2 or more cm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades more or less hairy, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Inflorescence terminal, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence with 2-10 branches, Inflorescence branches 1-sided, Flowers bisexual, Spikelets pedicellate, Spikelets sessile or subsessile , Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes shorter than adjacent lemma, Glume equal to or longer than spikelet, Glumes awned, awn 1-5 mm or longer, Glumes 3 nerved, Glumes 4-7 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma 3 nerved, Lemma 5-7 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea longer than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigm as 2, Fruit - caryopsis.

Habitat

    Habitat & Distribution
    provided by eFloras
    Moist places in forests and along forest margins, hill slopes. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Jiangxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [Japan, Philippines, Thailand, and elsewhere in tropical Asia extending westward through India to E Africa; Australia, Pacific Islands (Polynesia)].

Cyclicity

    Flower/Fruit
    provided by eFloras
    Fl. & Fr. Per.: August-September.