Acrachne

Wight & Arn. ex Chiov.
Treatment appears in FNA Volume 25. Treatment on page 110.
 TaxonIllustrator 
FNA25 P42A Acrachne pg 114.jpegAcrachne racemosaLinda A. Vorobik

Plants annual; tufted. Culms to approximately 50 cm, erect or geniculate, not woody. Sheaths open; ligules membranous, ciliate; blades broadly linear. Inflorescences terminal, panicles of spike¬like branches, exceeding the upper leaves; branches 1.5-10 cm, subdigitate or in whorls along elongate rachises, axes flattened, with imbricate, subsessile spikelets, terminating in a rudimentary spikelet. Spikelets laterally compressed, with 3-25 florets; disarticulation of the spikelets below the glumes, of the lemmas within the spikelets acropetal, spikelets falling wholly or in part after only a few lemmas have fallen, paleas persistent. Glumes 1-veined, keeled, exceeded by the florets; lemmas 3-veined, strongly keeled, firmly membranous to cartilaginous, glabrous, cuspidate or awn-tipped. Fruits modified caryopses, pericarp hyaline, rupturing at maturity; seeds deeply sulcate, ornamented, x = 9.

Discussion

Acrachne has four species, all of which are native to the Eastern Hemisphere. One species, Acrachne racemosa, which is widely distributed in the tropics, was recently found in southern California. The genus resembles Eleusine and Dactyloctenium in its fruits and ornamented seeds, but differs from both in its mode of disarticulation.

Lower Taxa

"decumbent" is not a number.

... more about "Acrachne"
1 +  and 3 +
Sylvia M. Phillips +
Wight & Arn. ex Chiov. +
1 (?) +  and 3 (?) +
multiple +, , +  and single +
flattened +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
pubescent +  and glabrous +
usually linear +  and lanceolate occasionally ovate +
in whorls +  and subdigitate +
spikelike +
1.5 cm15 mm <br />0.015 m <br /> (10 cm100 mm <br />0.1 m <br />) +
triangular +  and dome--shaped +
sometimes longer +
membranous +
geniculate +
1 cm10 mm <br />0.01 m <br /> (500 cm5,000 mm <br />5 m <br />) +
not woody +
not waisted +
capillary +
pistillate +  and staminate +
sometimes longer +
3 +  and 25 +
bisexual +  and fertile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
uncinate +
paniculate +  and racemose +
hollow +  and solid +
not absent +
awn-tipped +, cuspidate +  and 3-veined +
membranous to cartilaginous +  and membranous +
sometimes longer +
membranous +
inconspicuous +
concealed +  and prominent +
2 +  and 1 +
persistent +
dry +  and fleshy +
spikelike +
elongate +
clifford1996a +  and phillips1995a +
ornamented +
in part +  and falling +
1 +  and 60 +
compressed +
1 +  and 3 +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Acrachne +
Poaceae tribe Cynodonteae +
membranous +
7 (?) +  and 13 (?) +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +