Ampelodesmos

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Treatment appears in FNA Volume 24. Treatment on page 112.

Plants perennial; cespitose, rhizomatous. Culms 60-350 cm, annual, internodes solid. Leaves mostly basal; cleistogenes not developed; prophylls shorter than the sheaths; sheaths open; ligules membranous, ciliate; blades initially flat, becoming involute, bases becoming indurate and curved. Inflorescences panicles, loosely contracted, somewhat 1-sided. Spikelets pedicellate, laterally compressed, with 2-6 florets; rachillas hairy, hairs 2-3 mm, prolonged beyond the distal florets; disarticulation above the glumes and beneath the florets. Glumes subequal, more than 1/2 as long as the adjacent lemmas, scarious or chartaceous, 3-5-veined, awn-tipped; florets 10-12 mm; calluses 0.2-0.5 mm, rounded, strigose; lemmas coriaceous, smooth, 5-7-veined, mostly glabrous, hairy over and adjacent to the basal 1/2 of the midvein, hairs 1-2 mm, apices bidentate or bilobed, mucronate or awned from the sinuses, lemma-awn junction not conspicuous; paleas subequal to the lemmas, 2-keeled, keels extending as teeth, flat between the keels; lodicules 3, lanceolate, membranous, ciliate; anthers 3, 6-8 mm; ovaries pubescent distally; styles 2, white. Caryopses fusiform, subterete, grooved adaxially, not ribbed; hila linear; starch-grains simple, x = 12.

Discussion

Ampelodesmos is a monospecific, xerophytic genus that is native to the Mediterranean. It is now established in California. It is somewhat similar in overall shape to Cortaderia, but differs in its membranous ligules, drooping and somewhat one-sided panicles, and deeply ribbed leaves.

Ampelodesmos was initially included in the Stipeae by Decker (1964), who was struck by the similarity of its leaf cross sections to those of some members of the Stipeae. Other characteristics it shares with at least some members of the Stipeae are its 3 lodicules, relatively small chromosomes, pubescent ovaries, and deeply ribbed leaves. Molecular data also support its inclusion in the Stipeae (Soreng and Davis 1998; Hsiao et al. 1999; Jacobs et al. 2006). It is anomalous within the Stipeae in having more than one floret per spikelet and prolonged rachillas.

"decumbent" is not a number."prolonged" is not a number.

... more about "Ampelodesmos"
membranous +  and scarious +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
awned +, bifid +, bilobed +  and entire +
Awned (?) +, Mucronate (?) +, Bilobed (?) +  and Bidentate (?) +
James P. Smith +  and Jr. +
twisted +  and not branched +
1 (?) +  and 3 (?) +
subterminal +  and eccentric +
0.3 cm3 mm <br />0.003 m <br /> (30 cm300 mm <br />0.3 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
indurate +
not evident +
cross +, linear +  and narrowly lanceolate +
spikelike +
well-developed +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
solid +  and hollow +
ascending +  and erect +
60 cm600 mm <br />0.6 m <br /> (350 cm3,500 mm <br />3.5 m <br />) +
not woody +
0 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
2 +  and 6 +
compressed +  and terete +
10mm +  and 12mm +
awn-tipped +  and 3-5-veined +
1-10-veined +
subtending +
/2 +  and 1 +
narrowly lanceolate +  and ovate +
subequal +
chartaceous +  and scarious +
prolonged +
uncinate +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
basally concentrated +  and evenly distributed +
hairy +  and glabrous +
ovate +, rectangular +  and lanceolate +
coriaceous +
membranous +
inconspicuous +
lanceolate +
concealed +  and prominent +
2 +  and 1 +
well-developed +
2-keeled +
subequal +
dry +  and fleshy +
not prolonged +
decker1964a +, hsiao1999a +, jacobs2006a +  and soreng1998b +
1 +  and 60 +
unisexual +  and bisexual +
compressed +
1 (?) +  and 3 (?) +
2 (?) +  and 3 (?) +
Gramineae +
Ampelodesmos +
Poaceae tribe Stipeae +
membranous +
inconspicuous +
plant +  and cespitose +
aquatic +  and terrestrial +