HITCHCOCK AND CHASE—NORTH AMERICAN PANICUM. 67 
S 27. Panicum stramineum sp. nov. 
DESCRIPTION. 
Plants ascending or widely spreading, sparingly branching at the base and lower 
nodes, or simple, 20 to 50 cm. high; culms glabrous, the nodes appressed-villous; 
sheaths glabrous, sparsely papillose or 
papillose-hispid; blades erect or ascending, 
10 to 30 cm. long, 4 to 15 mm. wide, 
rounded or somewhat cordate at base, 
glabrous, scabrous on the margin and 
sometimes on the upper surface, some- 
times ciliate at base; panicles finally ex- 
serted, one-fourth to one-third the entire 
height of the plant, ovoid in outline, 
rather many-flowered, the pedicelsscarcely 
as appressed as in P. hirticaule; spikelets 
3.2 to 3.7 mm. long, 1.5 mm. wide, elliptic, 
abruptly acuminate, turgid, pale stramine- 
ous; first glume one-third the length of the spikelet, blunt or subacute, the 
nerves usually anastomosing; second glume and sterile lemma equal, or the glume 
. slightly shorter, not much exceeding the fruit, the palea of the sterile floret as long as 
the fruit, 2-nerved; fruit 2.2 mm. long, 1.3 mm. wide, obovate-elliptic, turgid, a rather 
prominent scar on either side at base. 
Type U.S. National Herbarium no. 592753, collected 1887, Guaymas, Sonora, Mex- 
ico, by Dr. Edward Palmer (no. 206). 
This species differs from P. hirti- 
caule in being nearly glabrous through- 
out, in the longer blades, more turgid, 
less long-pointed spikelets with shorter, 
scarcely acute first glume. 
Fig. 50.—P. stramincum. Fromtype specimen. 
DISTRIBUTION. 
Rich bottom lands and damp soil, 
southern Arizona and northwestern 
Mexico. 
Fig. 51.—Distribution of P. stramineum. 
Arizona: Near the Mexican boun- 
dary, Pringle in 1884; Tucson, Thornber in 1901, and 219 (the latter in N. M. 
Agr. Col. Herb.). 
Mexico: Guaymas, Palmer 168a and 206 in 1887; Culiacan, Palmer 1538 in 1891; 
State of Sinaloa, Rose 1878, 1883; Acaponeta, Rose 1889, 3281. 
s 28. Panicum sonorum Beal. 
Panicum capillare miliaceum Vasey, Contr. Nat. Herb. 1: 28 1890, not P. miliaceum 
L. 1753. Collected at Lerdo, Mexico, at the head of the Gulf of California, in 1889, 
Palmer 947. This is not based on P. miliaceum L. The type is in the National Her- 
barium. 
Panicum sonorum Beal, Grasses N. Amer. 2: 130.1896. Based on P.capillare milia- 
ceum Vasey. 
