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.

Nastus

HABIT Perennial. Rhizomes short; pachymorph. Culms erect (4/17), or leaning (1/17), or scandent (12/17); 100–1343–2600 cm long; woody. Culm-internodes terete. Lateral branches dendroid. Branch complement three (1/13), or several (1/13), or many (11/13); in a clump (1/1); apparently arising below the node (1), or at the node (24); with subequal branches (2/4), or 1 branch dominant (2/4), or 2 branches dominant (1/4). Culm-sheaths deciduous (1/1); auriculate (1/1). Culm-sheath blade lanceolate (1/4), or narrowly ovate (1/4), or triangular (2/4); constricted at base (2/2). Leaf-sheath auricles absent (23), or erect (1), or falcate (1). Ligule an eciliate membrane (21), or a ciliate membrane (1), or absent (3). Leaf-blade base without a false petiole (8), or with a brief petiole-like connection to sheath (17). Leaf-blades linear (8), or lanceolate (20), or oblong (1); stiff (3), or firm (22). Leaf-blade midrib conspicuous (3/3). Leaf-blade venation without cross veins (24), or with obscure cross veins (1).

INFLORESCENCE Inflorescence a panicle (20/23), or composed of racemes (1/23), or comprising only a few spikelets (2/23); subtended by an unspecialized leaf-sheath (22/23), or a spatheole (1/23); exserted (22/23), or embraced at base by subtending leaf (1/23).

Panicle open (12/17), or contracted (5/17).

Racemes single (1/1); bearing few fertile spikelets (1/1); bearing 3–4 fertile spikelets on each (1/1).

Spikelets solitary (23/23). Fertile spikelets sessile (3/19), or pedicelled (16/19).

FERTILE SPIKELETS Spikelets comprising 1–2 basal sterile florets (10/19), or 3 basal sterile florets (2/19), or 4 basal sterile florets (1/19); 1 fertile florets (22/23), or 2 fertile florets (1/23); without rhachilla extension (8/23), or with diminished florets at the apex (15/23). Spikelets lanceolate (7/23), or elliptic (1/23), or oblong (11/23), or ovate (10/23); laterally compressed (22/23), or subterete (1/23); 4.98–11.02–30 mm long; breaking up at maturity (23/23); disarticulating below each fertile floret (23/23).

GLUMES Glumes two (7/23), or several (16/23); shorter than spikelet (23/23), or reaching apex of florets (1/23). Lower glume linear (1/22), or lanceolate (2/22), or ovate (20/22); chartaceous (22/22); 1-keeled (1/1); 3 -veined (1/6), or 5 -veined (4/6), or 7 -veined (1/6). Lower glume surface without pits (23/23); glabrous (21/23), or puberulous (2/23), or pubescent (2/23). Lower glume apex obtuse (1/22), or acute (14/22), or acuminate (5/22), or setaceously attenuate (2/22); muticous (19/22), or mucronate (3/22). Upper glume lanceolate (1/23), or elliptic (1/23), or ovate (22/23); 0.2–0.25–0.3 length of adjacent fertile lemma; chartaceous (22/23), or coriaceous (1/23); without keels (23/23); 3 -veined (1/11), or 5 -veined (3/11), or 7 -veined (5/11), or 9 -veined (2/11). Upper glume surface glabrous (20/23), or puberulous (1/23), or pubescent (3/23), or pilose (1/23). Upper glume apex truncate (1/22), or obtuse (2/22), or acute (13/22), or acuminate (6/22), or setaceously attenuate (1/22); muticous (20/23), or mucronate (3/23).

FLORETS Basal sterile florets barren (19/19); with palea (5/19), or without significant palea (14/19). Lemma of lower sterile floret elliptic (3/19), or oblong (3/19), or ovate (13/19); 0.4–0.45–0.5 length of fertile lemma; coriaceous (19/19); 5 -veined (3/9), or 6 -veined (1/9), or 7 -veined (3/9), or 8 -veined (1/9), or 9 -veined (3/9), or 10 -veined (1/9), or 11 -veined (3/9); truncate (1/7), or obtuse (3/7), or acute (2/7), or acuminate (3/7); muticous (15/19), or mucronate (4/19). Fertile lemma elliptic (2/23), or oblong (2/23), or ovate (19/23); coriaceous (23/23); without keel (20/23), or keeled (3/23); wingless (23/23); 7 -veined (6/12), or 8 -veined (2/12), or 9 -veined (6/12), or 10 -veined (2/12), or 11 -veined (4/12), or 12–13 -veined (1/12). Lemma surface unwrinkled (23/23); without grooves (23/23); glabrous (15/23), or puberulous (3/23), or pubescent (5/23), or pilose (1/23), or hirsute (1/23); hairy on back (9/10), or between veins (1/10). Lemma apex entire (22/23), or dentate (1/23); 3 -fid (1/1); truncate (2/23), or obtuse (5/23), or acute (13/23), or acuminate (5/23); without ornament (21/23), or pubescent (2/23); muticous (21/23), or mucronate (2/23), or awned (1/23); 1 -awned (1/1). Palea 0.9–0.9667–1 length of lemma; coriaceous (23/23); 6 -veined (1/1); without keels (10/23), or 2-keeled (13/23). Palea keels eciliate (10/13), or ciliate (3/13). Palea surface glabrous (19/23), or puberulous (1/23), or pubescent (2/23), or pilose (1/23). Palea apex dentate (3/3). Apical sterile florets 1 in number (15/15); male (1/15), or barren (15/15); rudimentary (1/15), or lanceolate (2/15), or elliptic (13/15).

FLOWER Lodicules 3 (23/23); glabrous (14/23), or ciliate (9/23). Anthers 6 (23/23). Stigmas 3 (23/23). Ovary unappendaged (8/23), or umbonate (15/23); pubescent on apex (6/6).

FRUIT Caryopsis with adherent pericarp (23/23); obovoid (3/3).

DISTRIBUTION Africa (12), or Tropical Asia (13), or Pacific (1).

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