68 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
DESCRIPTION. 
Plants robust, erect or spreading, 60 cm. to over 1 meter high; culms glabrous or 
sparsely papillose-hispid, the nodes pubescent; sheaths papillose-hispid or nearly 
glabrous; blades 15 to 40 cm. long, 15 to 30 mm. wide, cordate-clasping at base, rather 
prominently nerved, glabrous or sparsely papillose- 
hispid; panicles large and more or less drooping, 
20 to 30 cm. long, densely flowered, the numerous 
branches narrowly ascending; spikelets 3 to 3.3 
mm. long, 1.1 mm. wide, lanceolate, strongly 
nerved, brownish; first glume half to two-thirds 
the length of the spikelet, acuminate; second glume 
slightly exceeding the sterile lemma, the palea of 
the sterile floret wanting; fruit 2.1mm.long,1 mm. 
wide, oblong-obovate, subacute. 
This species may be a cultivated form of P. 
hirticaule. It is large in all its vegetative parts. 
Fig. 52.—P. sonorum. Fromtype Palmer states that it is used as food by the Cocopa 
specimen. ; . z : 
Indians, the seed being sown in spring on wet 
ground. A specimen from the State of Chiapas in southern Mexico, Nelson 2959, is 
intermediate between this and P. hirticaule but is more robust than the latter species, 
the blades being 15 cm. long and 18 mm. wide. 
DISTRIBUTION. 
Rich bottom land, northwestern Mexico. 
Mexico: Lerdo, Palmer 947 in 1889; southwestern Chihuahua, Palmer 1 c in 1885; 
Culiacén, Palmer 1539 and 1554 in part in 1891. 
Vv 29. Panicum parcum sp. noy. 
DESCRIPTION. 
Plants sparingly branching from the middle or upper nodes; culms 30 to 50 cm. 
high, slender, erect or somewhat geniculate at base, glabrous; sheyihe rather sparingly 
papillose-hispid, glabrate toward the base; ligules 1 to 2 mm. long; blades ascending, 
Tather thin, linear, elongated, 10 to 30 cm. 
long, 2 to 6 mm. wide, slightly narrowed 
to the base, acuminate, sparsely pilose 
on both surfaces or glabrate, more or less 
ciliate; panicles short-exserted, the termi- 
nal 10 to 20 cm. long, half to two-thirds as 
wide (the axillary smaller), few-flowered, 
the few, slender, but not capillary, flex- 
uous branches solitary, remote, ascending, 
bearing ascending or appressed branchlets 
with scattered, rather long-pediceled 
spikelets; spik eee about 6mm. long, 1.8 
mm. wide, turgid, acuminate-pointed; 
first glume about half the length of the 
spikelet, pointed; second glume longer 
than the sterile lemma, both exceeding 
the fruit and pointed beyond it, the sterile 
palea about halfas long as its lemma; fruit 
3.3 mm. long, 1.4mm. wide. 
Type U. 8. National Herbarium no. 
ETT, collected October 9 to 15, 1891, on 
“mountain side, not very common,”’ TL ogtieee, on the Culiac4n River, Sinaloa, Mexico, 
by Edward Palmer (no. 1657). 
Fic. 53.—P. parcum. From type specimen. 
