Lasiacis

(Griseb.) Hitchc.
Treatment appears in FNA Volume 25. Treatment on page 387.
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 TaxonIllustrator 
FNA25 P149A Lasiacis pg 391.jpegLasiacis divaricata
Lasiacis ruscifolia
Hana Pazdírková
Linda A. Vorobik
Hana Pazdírková
Linda A. Vorobik

Plants perennial (rarely annual); cespitose. Culms 0.5-8 m, weakly lignified, erect, arching, climbing, or decumbent, rooting at the nodes. Sheaths open; ligules membranous, sometimes ciliate; pseudopetioles sometimes present; blades linear to ovate, bases slightly to strongly asymmetric. Inflorescences open or contracted panicles, rachises usually visible, even distally, spikelets attached obliquely to the pedicels; disarticulation below the glumes. Spikelets subglobose to globose, with 2 florets. Glumes membranous, apices lanate pubescent, abruptly apiculate; lower glumes 1/3 – 2/3 as long as the spikelets, 5-13-veined, bases saccate, margins overlapping; upper glumes about as long as the upper florets, not saccate, 7-15-veined; lower florets sterile or staminate; lower lemmas membranous, apices lanate pubescent, abruptly apiculate; lower paleas present, sometimes reduced; upper florets stipitate, bisexual, appearing to mucronate or acuminate; upper lemmas indurate, usually broadly elliptic to obovate, margins enclosing the edges of the paleas, apices obtuse, somewhat woolly-pubescent, usually dark-brown at maturity; upper paleas similar to the lemmas, but saccate below and gibbous above. Caryopses planoconvex, ovoid, or nearly orbicular; embryo about M as long as the caryopses; hila oblong to nearly round, x = 9.

Distribution

Puerto Rico, Virgin Islands, Fla.

Discussion

In Lasiacis the upper florets appear to be mucronate or acuminate. The mucro or acuminate apex is formed by the tuft of hairs at the apex of the upper floret.

Lasiacis is a neotropical genus of 16 species that extends from southern Florida to Peru and Argentina. Two species are native to the Flora region. The shiny black color of its mature florets and the oil-filled cells of the inner epidermes of the glumes and sterile lemmas distinguish Lasiacis from all other grasses. Birds are a common dispersal agent.

Key

1 Leaf blades linear-lanceolate to narrowly lanceolate, 3-16 cm long, 3-30 mm wide Lasiacis divaricata
1 Leaf blades ovate to broadly lanceolate, 2-16 cm long, 8-56 mm wide Lasiacis ruscifolia

"decumbent" is not a number.

... more about "Lasiacis"
dark-brown +
woolly-pubescent +, pubescent +  and lanate +
anatomy +  and kranz +
Gerrit Davidse +
(Griseb.) Hitchc. +
1 (?) +  and 3 (?) +
keeled +  and rounded +
pseudopetiolate +  and branching +
saccate +  and asymmetric +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
linear +  and ovate +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not developed +
orbicular +, ovoid +  and planoconvex +
sometimes longer +
decumbent +  and climbing +
arching +  and erect +
50 cm500 mm <br />0.5 m <br /> (800 cm8,000 mm <br />8 m <br />) +
lignified +
Puerto Rico +, Virgin Islands +  and Fla. +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
uncinate +
solid +  and hollow +
cauline +  and basal +
coriaceous +
membranous +
inconspicuous +
1/3 +  and 2/3 +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
subterranean +
dry +  and fleshy +
davidse1973a +  and davidse1978a +
in triplets +  and paired +
1 +  and 60 +
unisexual +  and bisexual +
subglobose +  and globose +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Gramineae +
Lasiacis +
Poaceae tribe Paniceae +
membranous +
acuminate +  and mucronate +
usually broadly elliptic +  and obovate +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +