302 MISC. PUBLICATION 243, U.S. DEPT. OF AGRICULTURE 
82. LASIACIS (Griesb.) Hitche., Contrib. U. S. Natl. Herb. 15: 16. 
1910. TIBISEE 
(Panicum section Lasiacis Griseb., Fl. Brit. W. Ind. 551. 1864) 
Spikelets subglobose, placed obliquely on their pedicels; first glume 
broad, somewhat inflated-ventricose, usually not more than one-third 
the length of the spikelet; second glume and sterile lemma about 
equal, broad, abruptly apiculate, papery-chartaceous, shining, many- 
nerved, glabrous, or lanose at the apex only, the lemma enclosing a 
membranaceous palea and sometimes a staminate flower; fertile lemma 
white, bony-indurate, obovoid, obtuse, this and the palea of the same 
texture bearing at the apex in a slight crateriform depression a tuit of 
woolly hairs, the palea concave below, gibbous above, the apex often 
free at maturity. Large branching perennials with woody culms, 
often clambering, mostly firm blades narrowed into a minute petiole, 
and open or slightly compact panicles. 
Main culm prostrate, the fertile shoots prostrate, ascending, or erect. 
Blades lanceolate, mostly less than 5 cm long; fertile shoots strongly dorsiventral 
mostly prostrate i Ie Seer. fee 8 ae eae OS 1. L. RUGELII. 
Blades linear-lanceolate, mostly 10 to 12 cm long; fertile shoots ascending or 
erect from a decumbent base, not dorsiventral_______ 2. L. GRISEBACHII. 
Main culm clambering or much branched and forming a tangled mass. 
Ligule noticeable, brownish, about 2 mm long. 
Blades glabrous beneath, scabrous on both surfaces, elongate, more than 10 
times as long as wide; plants not forming a strong central clambering 
Gane? A) £ Ba e N _  pe 3. L. OAXACENSIS. 
Blades puberulent beneath, glabrous or scabrous on the upper surface, less 
than 10 times as long as wide; plants forming a strong central clambering 
Gan@t. #2... 5 gee 220 ee eee 4, L. LIGULATA. 
Ligule inconspicuous, hidden within the mouth of the sheath, rarely as much as 
1 mm long. 
Plants not high-climbing, decumbent and rooting at base, forming a tangled 
mass, with no strong central cane; spikelets clustered toward the ends of 
thesbranches 2 <5 et. 2 ee 5. lL. RHIZOPHORA. 
Plants high-climbing, forming a strong central cane; spikelets not clustered 
toward the ends of the branches. 
Blades glabrous on both surfaces, often more or less scabrous. 
Blades narrow, usually 3 to 4 mm, sometimes 5 mm, wide, 8 to 10 em 
long. ek 2 ee ee ee 6. L. HARRISII. 
Blades more than 5 mm wide, if as much as 10 em long. 
Panicles few-flowered, 5 to 10 em long; branches strongly zigzag, the 
branchlets strongly divaricate or reflexed; blades narrowly 
lanceolate, firm, mostly less than 1 em wide (sometimes wider on 
VigOrous Shoots) 5.528 eee ee eee 7. L. DIVARICATA. 
Panicles many-flowered, usually 15 to 25 em long or more on the 
primary branches; branches straight or arcuate, not zigzag; 
blades mostly more than 1.5 em wide. 
Spikelets 4.5 to 5 mm long, on short stiff appressed pedicels; blades 
oblong-ovate or elliptic_lanceolate sigh 3 8. LL. SLOANEI. 
Spikelets 3.5 to 4 mm long on flexuous spreading pedicels, blades 
lanceolate or narrowly Janceolate______ 9. L. PATENTIFLORA. 
Blades pubescent on one or both surfaces (rarely nearly glabrous in 
L. ruscifolia). 
Blades narrowly lanceolate, averaging 8 to 10 times as long as wide; 
panicle large and open; spikelets 4 to 5 mm long. 
10. L. sorGHOIEA. 
Blades ovate-lanceolate or elliptic, sometimes lanceolate, often more or 
less cordate-clasping; panicle often compact, or at least the branches 
commonly compactly flowered; spikelets 3 to 4 mm long. 
Sterile lemma t= — ._,2 see coe 11. L. RUS¢CIFOLIA- 
pterledemmas 22.) eee ee ae eae 12. L. ANOMALA- 
