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.

Atractantha

HABIT Perennial. Rhizomes short; pachymorph. Culms scandent; 456–973.6–2000 cm long; woody; without nodal roots (1/1). Culm-internodes terete. Culm-nodes with distinct supra-nodal ridge (1/1). Lateral branches dendroid. Branch complement one (1), or two (1), or three (2), or several (3), or many (1); in a horizontal line (2/2); with 1 branch dominant (4/4); thinner than stem. Culm-sheaths persistent (2/4), or deciduous but leaving a persistent girdle (4/4); without auricles (2/3), or auriculate (1/3). Culm-sheath blade linear (1/4), or lanceolate (1/4), or triangular (2/4); as wide as sheath at base (2/2). Leaf-sheath auricles absent, or erect (1). Ligule an eciliate membrane. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades linear (1), or lanceolate. Leaf-blade venation without cross veins (5), or with obscure cross veins (1).

INFLORESCENCE Synflorescence simple (1/5), or bractiferous (4/5); paniculate (2/4), or fasciculate (1/4), or globose (1/4); with glumaceous subtending bracts (4/4), or foliaceous subtending bracts (3/4); with axillary buds at base of spikelet (3/3). Inflorescence composed of racemes (1/1).

Racemes single (1/1); bearing 8–13 fertile spikelets on each (1/1).

Spikelets appressed (1/1), or ascending (1/1). Fertile spikelets sessile (1/5), or pedicelled (4/5).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets (5/5); without rhachilla extension (3/5), or with a barren rhachilla extension (5/5), or with diminished florets at the apex (3/5). Spikelets linear (1/5), or lanceolate (5/5); subterete (5/5); 12.45–23.94–36 mm long; falling entire (4/5), or breaking up at maturity (1/5); disarticulating below each fertile floret (1/1). Rhachilla internodes brief up to lowest fertile floret (4/5), or elongated between glumes (1/5), or elongated below proximal fertile floret (1/5).

GLUMES Glumes both absent or obscure (4/5), or two (1/5); shorter than spikelet (1/1); thinner than fertile lemma (1/1). Lower glume elliptic (1/1); membranous (1/1); without keels (1/1); 5 -veined (1/1). Lower glume surface without pits (1/1). Lower glume apex awned (1/1). Upper glume lanceolate (1/1); membranous (1/1); without keels (1/1); 7 -veined (1/1). Upper glume mucronate (1/1), or awned (1/1); 1 -awned (1/1).

FLORETS Fertile lemma lanceolate (5/5); subterete (5/5); chartaceous (2/5), or coriaceous (3/5); without keel (5/5); wingless (5/5); 7–9 -veined (2/3), or 10 -veined (1/3), or 11 -veined (2/3), or 12–15 -veined (1/3). Lemma lateral veins obscure (1/1). Lemma surface smooth (5/5), or scaberulous (1/5); unwrinkled (5/5); without grooves (5/5); glabrous (4/5), or pubescent (1/5). Lemma margins convolute (5/5); covering most of palea (5/5); eciliate (4/5), or ciliolate (1/5). Lemma apex acuminate (3/4), or setaceously attenuate (1/4); muticous (4/5), or pungent (1/5), or awned (1/5); 1 -awned (1/1). Palea tightly convolute around flower (5/5); 1–1.05–1.1 length of lemma; chartaceous (4/5), or coriaceous (1/5); 2 -veined (2/3), or 4 -veined (1/3). Palea keels separated (1/5), or approximate (3/5), or contiguous above a sulcus (1/5); eciliate (2/5), or ciliolate (4/5). Palea apex lobed (1/1). Apical sterile florets 1 in number (1/1); lanceolate (1/1).

FLOWER Lodicules absent (1/5), or 3 (4/5); membranous (4/4); glabrous (1/4), or ciliate (3/4). Anthers 3 (5/5). Stigmas 2 (5/5), or 3 (1/5). Ovary unappendaged (4/5), or umbonate (1/5); glabrous (2/4), or pubescent on apex (2/4).

FRUIT Caryopsis with adherent pericarp (5/5).

DISTRIBUTION South America.

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