é 
HITCHCOCK AND CHASE—TROPICAL NORTH AMERICAN PANICUM. 489 
line, open, the slender scabrous branches ascending and spreading, fascicled, some 
naked at base, with short branchlets intermixed; spikelets rather short-pediceled, 3.2 
to 4 mm. long, about 1.2 mm. wide, turgid, glabrous, 
the glumes and sterile lemma strongly nerved, pointed, 
somewhat keeled, usually widely gaping, the first 
glume about two-thirds the length of the spikelet, 
the second glume and sterile lemma exceeding the 
fruit, subequal; fruit 2 to 2.2 mm. long, 1 mm. wide, 
elliptic. 
_ Type in the U.S. National Herbarium, no. 693326, 
collected in moist sandy soil, near sea beach on Point 
Chamé, Province of Panama, September 18, 1911, by 
A. 8. Hitchcock (no. 8167). 
In the inflorescence this species closely resembles 
P. virgatum, but in habit it differs distinctly. It 
grows in masses like large reeds such as Phragmites but is straggling and much 
tangled at base. 
Fig. 57.—P. altum. From 
type specimen. 
DISTRIBUTION. 
Sandy marshes or flats near the seacoast, British Honduras to Trinidad. 
British Honpuras: Manatee Lagoon, 
Peck 123 (Gray Herb.). 
Costa Rica: Buenos Aires, Tonduz3619. 
Panama: Point Chamé, Hitchcock 8167. 
TRINIDAD: Near Port of Spain, Hitch- 
cock 10053. Icacos, Hitchcock 10154. 
Three miles south of Cedros, Hitch- 
cock 10159. 
Topaco: Plymouth, Hitchcock 10233. 
Fig. 58.Distribution of P. aliwm. i Pigeon Point, Broaduer ay 3068. 
4 / Fal 2 anicum. fac araia VaEey. 
Panicum havardii Vasey, Bull. Torrey 
Club 14: 95.1887; Contr. U.S. Nat. Herb. 
15: 93. 1910. 
DISTRIBUTION. 
Arroyos and sand hills, southwestern 
United States and northern Mexico. : The 
type specimen from Texas. 
Cuinuanua: Paso del Norte (Juarez), 
Pringle 1124. Fig. 59.—Distribution of P. havardii. 
43. Panicum amarulum Hitche. & Chase. 
Panicum amarulum Hitche. & Chase, Contr. U. S. Nat. Herb. 15: 96. 1910. 
DISTRIBUTION. 
Sandy seashores and coast dunes, 
~ southeastern United States, Bahamas, 
and Cuba. The type specimen from 
Virginia. 
3AHAMAS: Great Bahama, Britton 
& Millspaugh 2739. New 
Providence, Britton & Brace 
307, 493 (all Field Mus. Herb.). 
CugBa: Camaguey, Shafer 2735. 
Fra. 60.—Distribution of P. amarulum. 
