Nastus

HABIT Perennial. Rhizomes short; pachymorph. Culms erect (4/16), or leaning (1/16), or scandent (11/16); 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 (23); 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 (22), or erect (1), or falcate (1). Ligule an eciliate membrane (20), 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 (16). Leaf-blades linear (8), or lanceolate (19), or oblong (1); stiff (3), or firm (21). Leaf-blade midrib conspicuous (3/3). Leaf-blade venation without cross veins (23), or with obscure cross veins (1).

INFLORESCENCE Inflorescence a panicle (19/22), or composed of racemes (1/22), or comprising only a few spikelets (2/22); subtended by an unspecialized leaf-sheath (21/22), or a spatheole (1/22); exserted (21/22), or embraced at base by subtending leaf (1/22).

Panicle open (11/16), or contracted (5/16).

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

Spikelets solitary (22/22). Fertile spikelets sessile (3/18), or pedicelled (15/18).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets (5/5), or 2 basal sterile florets (1/5); 1 fertile florets (21/22), or 2 fertile florets (1/22); without rhachilla extension (7/22), or with diminished florets at the apex (15/22). Spikelets lanceolate (7/22), or elliptic (1/22), or oblong (11/22), or ovate (9/22); laterally compressed (21/22), or subterete (1/22); 4.98–11.02–30 mm long; breaking up at maturity (22/22); disarticulating below each fertile floret (22/22).

GLUMES Glumes two (1/22), or several (21/22); lower persistent, upper deciduous (14/14); shorter than spikelet (22/22). Lower glume linear (1/21), or lanceolate (2/21), or ovate (19/21); chartaceous (21/21); 1-keeled (1/1); 3 -veined (1/6), or 5 -veined (4/6), or 7 -veined (1/6). Lower glume surface without pits (22/22); glabrous (20/22), or puberulous (2/22), or pubescent (2/22). Lower glume apex obtuse (1/21), or acute (13/21), or acuminate (5/21), or setaceously attenuate (2/21); muticous (18/21), or mucronate (3/21). Upper glume lanceolate (1/22), or elliptic (4/22), or oblong (3/22), or ovate (15/22); chartaceous (9/22), or coriaceous (13/22); without keels (20/22), or 1-keeled (2/22); 5 -veined (2/10), or 6 -veined (1/10), or 7 -veined (5/10), or 9 -veined (2/10), or 10 -veined (1/10), or 11 -veined (3/10). Upper glume surface glabrous (15/22), or puberulous (4/22), or pubescent (5/22), or pilose (2/22). Upper glume apex entire (21/22), or dentate (1/22); 3 -fid (1/1); truncate (1/21), or obtuse (2/21), or acute (11/21), or acuminate (7/21), or setaceously attenuate (1/21); muticous (17/22), or mucronate (5/22).

FLORETS Basal sterile florets barren (5/5); with palea (5/5). Lemma of lower sterile floret ovate (5/5); coriaceous (5/5); 7–9 -veined (1/1); obtuse (1/1); muticous (4/5), or mucronate (1/5). Fertile lemma elliptic (2/22), or oblong (2/22), or ovate (18/22); coriaceous (22/22); without keel (19/22), or keeled (3/22); wingless (22/22); 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 (22/22); without grooves (22/22); glabrous (14/22), or puberulous (3/22), or pubescent (5/22), or pilose (1/22), or hirsute (1/22); hairy on back (9/10), or between veins (1/10). Lemma apex entire (21/22), or dentate (1/22); 3 -fid (1/1); truncate (2/22), or obtuse (5/22), or acute (12/22), or acuminate (5/22); without ornament (20/22), or pubescent (2/22); muticous (20/22), or mucronate (2/22), or awned (1/22); 1 -awned (1/1). Palea 0.9–0.9667–1 length of lemma; coriaceous (22/22); 6 -veined (1/1); without keels (9/22), or 2-keeled (13/22). Palea keels eciliate (10/13), or ciliate (3/13). Palea surface glabrous (18/22), or puberulous (1/22), or pubescent (2/22), or pilose (1/22). 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 (22/22); glabrous (13/22), or ciliate (9/22). Anthers 6 (22/22). Stigmas 3 (22/22). Ovary unappendaged (7/22), or umbonate (15/22); pubescent on apex (6/6).

FRUIT Caryopsis with adherent pericarp (22/22); obovoid (3/3).

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

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.