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.

Muhlenbergia

HABIT Annual (34), or perennial (128). Rhizomes absent (122), or short (12), or elongated (28). Stolons absent (157), or present (2). Culms erect (80/115), or geniculately ascending (31/115), or decumbent (27/115), or prostrate (5/115); robust (11/40), or slender (24/40), or weak (5/40); 1–55.99–300 cm long; firm (148), or wiry (9), or woody (2); without nodal roots (7/16), or rooting from lower nodes (15/16). Culm-internodes terete (1/2), or elliptical in section (1/2). Culm-nodes constricted (1/2), or flush with internodes (1/2). Lateral branches lacking (13/48), or sparse (10/48), or ample (31/48), or fastigiate (1/48). Leaf-sheath auricles absent (145), or erect (17). Ligule an eciliate membrane (139), or a ciliolate membrane (21), or a ciliate membrane (1). Leaf-blades persistent (157), or deciduous at the ligule (4); filiform (12), or linear (148), or lanceolate (1); herbaceous (157), or coriaceous (2); stiff (10), or firm (148), or flaccid (1). Leaf-blade midrib conspicuous (5/8), or widened (3/8). Leaf-blade margins unthickened (1/12), or cartilaginous (12/12). Leaf-blade apex muticous (157), or pungent (2).

INFLORESCENCE Inflorescence a panicle (158), or composed of racemes (1), or comprising only a few spikelets (1); terminal (154), or terminal and axillary (5); not deciduous as a whole (158), or deciduous as a whole (2); exserted (156), or embraced at base by subtending leaf (8).

Panicle open (98/158), or contracted (52/158), or spiciform (16/158). Primary panicle branches not whorled (157/158), or whorled at most nodes (1/158). Panicle axis bearing persistent branches (156/158), or deciduous branches (3/158).

Racemes borne along a central axis (1/1); spreading (1/1), or drooping (1/1); paucilateral (1/1); bearing few fertile spikelets (1/1); bearing 2–4 fertile spikelets on each (1/1). Rhachis deciduous from axis (1/1). Spikelet packing distant (1/1).

Spikelets appressed (17/25), or ascending (3/25), or spreading (5/25), or pendulous (2/25), or deflexed (3/25); solitary, or in pairs (1). Fertile spikelets sessile (2), or pedicelled (157). Pedicels filiform (39/60), or linear (17/60), or oblong (3/60), or reduced to a stump (1/60); tip widened (8/9), or pyriform (1/9).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets, or 2 fertile florets (1); without rhachilla extension (158), or with a barren rhachilla extension (1), or with diminished florets at the apex (4). Spikelets lanceolate (154), or elliptic (3), or oblong (1), or ovate (1); laterally compressed (157), or subterete (1), or dorsally compressed (1); 0.9–3.176–8.4 mm long; falling entire (3), or breaking up at maturity (157); deciduous with accessory branch structures (3/3); disarticulating below each fertile floret (157/157). Spikelet callus pubescent (1/1). Rhachilla internodes definite (1/1). Floret callus glabrous (13/71), or sparsely hairy (1/71), or pubescent (49/71), or pilose (7/71), or bearded (1/71); truncate (2), or obtuse (157).

GLUMES Glumes one the lower absent or obscure (1), or two (158); persistent (157/157); shorter than spikelet (118), or reaching apex of florets (36), or exceeding apex of florets (26); thinner than fertile lemma (8), or similar to fertile lemma in texture (151). Lower glume linear (2/157), or lanceolate (112/157), or elliptic (16/157), or oblong (19/157), or ovate (22/157), or orbicular (2/157), or obovate (1/157); 0.25–0.9075–1 length of upper glume; hyaline (4/157), or membranous (151/157), or chartaceous (1/157), or coriaceous (1/157); without keels (119/157), or 1-keeled (38/157); 0 -veined (8/157), or 1 -veined (152/157), or 2 -veined (4/157), or 3 -veined (2/157), or 4–5 -veined (1/157). Lower glume lateral veins absent (154/158), or obscure (1/158), or distinct (5/158). Lower glume surface smooth (130/158), or asperulous (29/158), or scabrous (17/158); without pits (158/158); glabrous (143/158), or puberulous (6/158), or pubescent (5/158), or pilose (4/158), or hirsute (1/158), or villous (1/158), or hispidulous (1/158). Lower glume apex entire (149/158), or erose (10/158), or dentate (4/158); 2 -fid (4/4); emarginate (2/157), or truncate (4/157), or obtuse (42/157), or acute (97/157), or acuminate (44/157), or attenuate (12/157), or setaceously attenuate (10/157); muticous (141/157), or mucronate (22/157), or awned (21/157). Upper glume linear (2), or lanceolate (109), or elliptic (16), or oblong (22), or ovate (22), or orbicular (2), or obovate (2); 0.05–0.7304–2.5 length of adjacent fertile lemma; hyaline (6), or membranous (151), or chartaceous (1), or coriaceous (1); without keels (121), or 1-keeled (38); 0 -veined (8/152), or 1 -veined (140/152), or 2 -veined (4/152), or 3 -veined (13/152), or 4–5 -veined (1/152). Upper glume primary vein eciliate (154/156), or ciliolate (1/156), or pubescent (1/156). Upper glume lateral veins parallel at apex (1/1). Upper glume surface smooth (131), or asperulous (30), or scabrous (19); glabrous (144), or puberulous (4), or pubescent (6), or pilose (4), or hirsute (1), or villous (1), or hispidulous (1). Upper glume apex entire (144), or erose (11), or dentate (12), or lobed (1); 2 -fid (6/13), or 3 -fid (10/13), or 4 -fid (1/13); emarginate (2/158), or truncate (9/158), or obtuse (44/158), or acute (87/158), or acuminate (45/158), or attenuate (14/158), or setaceously attenuate (12/158); muticous (139), or mucronate (22), or awned (26), or awned only on distal spikelets (1); 1 -awned (25/25), or 3 -awned (1/25).

FLORETS Fertile lemma linear (8), or lanceolate (123), or elliptic (18), or oblong (8), or ovate (8), or oblanceolate (1); subterete (1/2), or dorsally compressed (1/2); membranous (151), or cartilaginous (6), or coriaceous (2); without keel (120), or keeled (39); wingless; 1 -veined (1), or 3 -veined (158). Lemma midvein without distinctive roughness (157), or scabrous (2); eciliate (130), or ciliolate (2), or ciliate (1), or pubescent (27). Lemma lateral veins obscure (8/18), or prominent (10/18); excurrent (2/2). Lemma surface smooth (113), or granulose (3), or asperulous (6), or scaberulous (29), or scabrous (26); unwrinkled; without grooves; glabrous (105), or puberulous (6), or pubescent (32), or pilose (12), or villous (6); hairy on back (50/56), or on veins (3/56), or between veins (3/56). Lemma margins eciliate (122), or ciliolate (3), or ciliate (8), or pubescent (30), or villous (1). Lemma apex entire (127), or erose (3), or dentate (29), or lobed (2); 2 -fid (30/31), or 4 -fid (1/31); incised 0.25–0.3183–0.5 of lemma length; emarginate (3/135), or truncate (1/135), or obtuse (15/135), or acute (66/135), or acuminate (55/135), or attenuate (7/135), or setaceously attenuate (1/135), or apiculate (2/135); muticous (51), or pungent (1), or mucronate (27), or awned (119); 1 -awned (118/119), or 3 -awned (1/119). Principal lemma awn apical (108/136), or subapical (6/136), or from a sinus (23/136); straight (95/136), or curved (1/136), or flexuous (44/136), or coiled (1/136), or hooked (1/136), or geniculate (1/136); 0.9–1–1.1 length of lemma. Palea 0.5–0.984–1.1 length of lemma; membranous (155), or cartilaginous (4); 2 -veined. Palea keels smooth (158), or scaberulous (1); eciliate (158), or pubescent (1), or ciliolate (1). Palea surface glabrous (122), or puberulous (3), or pubescent (22), or pilose (11), or villous (4). Palea apex dentate (2/3), or lobed (1/3); muticous (150), or with excurrent keel veins (8), or awned (1). Apical sterile florets 0 in number (1/4), or 1 in number (4/4); male (4/4), or barren (2/4); lanceolate (4/4). Apical sterile lemmas muticous (3/4), or awned (1/4).

FLOWER Lodicules 2; fleshy (158/158); truncate (1/1). Anthers 1 (1/152), or 3 (150/152), or 11–12 (1/152). Ovary glabrous (1/1).

FRUIT Caryopsis with adherent pericarp (158/158); linear (1/143), or fusiform (133/143), or ellipsoid (6/143), or oblong (3/143); isodiametric (1/1). Embryo 0.25–0.485–0.75 length of caryopsis. Hilum punctiform (1/1).

CLEISTOGENES AND VIVIPARY Cleistogenes absent (157), or present (2); in lower sheaths (2/2).

DISTRIBUTION Temperate Asia (7), or Tropical Asia (4), or Pacific (1), or North America (134), or South America (46).

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