GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Ortachne

HABIT Perennial. Rhizomes absent (1), or elongated (2). Culms erect; 12–25.66–44 cm long. Ligule an eciliate membrane. Leaf-blades aciculate (1), or filiform; stiff. Leaf-blade apex muticous (1), or pungent (2).

INFLORESCENCE Inflorescence a panicle.

Panicle open (2), or contracted (1).

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 2.075–3.779–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; pubescent (2), or pilose (1); acute.

GLUMES Glumes persistent; shorter than spikelet; thinner than fertile lemma (2), or similar to fertile lemma in texture (1). Lower glume oblong; 1–1.033–1.1 length of upper glume; hyaline (2), or membranous (1); without keels; 0 -veined (1), or 1 -veined, or 2–3 -veined (1). Lower glume lateral veins absent, or obscure (1). Lower glume surface without pits. Lower glume apex emarginate, or truncate. Upper glume oblong; 0.5–0.7333–0.9 length of adjacent fertile lemma; hyaline (2), or membranous (1); without keels; 0 -veined (2), or 1 -veined, or 2–3 -veined (1). Upper glume apex entire, or erose (2); emarginate (1), or truncate (1), or obtuse (2).

FLORETS Fertile lemma elliptic; membranous; without keel (1), or keeled (2); wingless; 3 -veined (1), or 5 -veined (2). Lemma midvein without distinctive roughness (2), or scabrous (1); eciliate (1), or pubescent (2). Lemma lateral veins obscure (2/2). Lemma surface smooth (2), or scaberulous (1); unwrinkled; without grooves. Lemma margins eciliate (2), or ciliate (2). Lemma apex entire (1), or dentate (2); 2 -fid (2/2); acuminate; awned; 1 -awned. Principal lemma awn straight (1), or curved (2), or flexuous (1). Palea 0.9–0.9667–1 length of lemma; 2 -veined; without keels. Palea surface glabrous (2), or pubescent (1), or pilose (1).

FLOWER Lodicules 2 (1), or 3 (2); membranous; truncate (1/2), or obtuse (1/2). Anthers 3.

FRUIT Caryopsis with adherent pericarp; fusiform (2/2); rugose (1/1). Hilum linear (1/1); 1 length of caryopsis.

DISTRIBUTION South America.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.