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.

Piptochaetium

HABIT Perennial. Rhizomes absent (36), or short (1). Culms erect (19/19), or geniculately ascending (6/19); slender (3/3); 10–51.06–150 cm long; compressible (1), or firm (35), or wiry (1). Culm-internodes elliptical in section (1/1). Culm-nodes constricted (2/3), or swollen (1/3). Lateral branches lacking (3/3). Ligule an eciliate membrane. Leaf-blades filiform (18), or linear (19); stiff (2), or firm (35).

INFLORESCENCE Inflorescence a panicle; exserted (34), or embraced at base by subtending leaf (9).

Panicle open (22), or contracted (15). Primary panicle branches not whorled (34), or whorled at lower nodes (3).

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform (4/4).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear (2), or lanceolate (4), or oblong (29), or obovate (2); laterally compressed (29), or subterete (8); 2.49–8.85–30 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief (17), or evident (6), or elongated (14); glabrous (4/36), or sparsely hairy (2/36), or pubescent (18/36), or pilose (13/36), or bearded (1/36); truncate (1), or obtuse (19), or acute (6), or pungent (11).

GLUMES Glumes persistent; shorter than spikelet (1), or reaching apex of florets (3), or exceeding apex of florets (34); thinner than fertile lemma; parallel to lemmas (35), or gaping (2). Lower glume lanceolate (21), or elliptic (3), or oblong (1), or ovate (11), or obovate (1); 0.75–1.043–1.5 length of upper glume; hyaline (27), or membranous (10); without keels; 1 -veined (2/35), or 2 -veined (1/35), or 3 -veined (14/35), or 4 -veined (7/35), or 5 -veined (26/35), or 6–7 -veined (3/35), or 8–9 -veined (1/35). Lower glume lateral veins absent (2), or distinct (36). Lower glume surface smooth, or asperulous (2); without pits. Lower glume apex obtuse (1/36), or acute (3/36), or acuminate (21/36), or attenuate (4/36), or setaceously attenuate (8/36); muticous (28), or awned (9). Upper glume lanceolate (21), or elliptic (2), or oblong (2), or ovate (11), or obovate (1); 0.75–1.15–1.5 length of adjacent fertile lemma; hyaline (27), or membranous (10); with undifferentiated margins (33), or hyaline margins (4); without keels; 1 -veined (2/35), or 2 -veined (1/35), or 3 -veined (16/35), or 4 -veined (7/35), or 5 -veined (24/35), or 6–7 -veined (3/35), or 8–9 -veined (1/35). Upper glume surface smooth, or asperulous (2). Upper glume apex obtuse (1), or acute (4), or acuminate (21), or attenuate (4), or setaceously attenuate (7); muticous (28), or awned (9); 1 -awned (9/9).

FLORETS Fertile lemma linear (2), or elliptic (1), or oblong (14), or orbicular (2), or obovate (14), or oblanceolate (5); laterally compressed (29), or subterete (8); not gibbous (17), or gibbous (20); coriaceous (6), or indurate (31); without keel (33), or keeled (4); wingless; 5 -veined (6/6). Lemma lateral veins without ribs (36), or ribbed (1). Lemma surface smooth (15), or granulose (1), or scaberulous (2), or scabrous (1), or papillose (10), or tuberculate (4), or striate (9); unwrinkled; without grooves (36), or with a median groove (1); glabrous (25), or pubescent (10), or pilose (2); without hair tufts (36), or with conspicuous apical hairs (1). Lemma margins involute (33), or convolute (4); covering most of palea (4), or interlocking with palea keels (33). Lemma apex truncate (9/9); without ornament (30), or scabrous (6), or pubescent (1); without appendage (13), or with an annular corona (6), or with a membranous corona (4), or surmounted by a ring of hairs (14), or with a short cylindrical neck (1), or with a conical beak (1); awned; 1 -awned. Principal lemma awn median (14), or eccentric (23); straight (1), or flexuous (3), or geniculate (8), or bigeniculate (27); limb glabrous (36), or puberulous (1). Column of lemma awn glabrous (15/33), or puberulous (11/33), or pubescent (7/33). Palea embraced by lemma (35), or reflexed at apex (2); 0.9–0.9969–1 length of lemma; 2 -veined (33/33); without keels (4), or 2-keeled (33). Palea keels separated (2/33), or contiguous above a sulcus (31/33). Palea surface glabrous (36), or pubescent (1).

FLOWER Lodicules 2 (6/14), or 3 (8/14). Anthers 3 (20/20). Stigmas 2 (6/6). Ovary glabrous (3/3).

FRUIT Caryopsis with adherent pericarp (31/31); fusiform (3/11), or oblong (1/11), or orbicular (4/11), or obovoid (3/11); laterally compressed (1/1). Embryo 0.2–0.2933–0.4 length of caryopsis. Hilum linear (22/22); 0.7–0.9682–1 length of caryopsis.

DISTRIBUTION Australasia (3), or North America (9), or South America (29).

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