486 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM, 
VIRGATA. 
Perennials, mostly with stout rootstocks, one species, P. ichnanthoides found to be 
without rootstocks. 
Creeping rootstocks wanting........-...... 
Creeping rootstocks present. 
a we ceee ss. .... 40. P. ichnanthoides. 
Spikelets not over 2.5 mm. long; first glume less than half the 
length of the spikelet. 
Panicles loosely flowered; first glume truncate, about 
one-fifth the length of the spikelet....... eeeeee 37. P. repens. 
Panicles rather densely flowered; first glume triangular, 
about one-third the length of the spikelet.....-. 38. P. gouini. 
Spikelets 3 to 7 mm. long (sometimes less than 3 mm. in P. 
virgatum cubense) ; first glume more than half thelength 
of the spikelet. 
Culms decumbent or creeping at base. 
Spikelets 3.2 to 4 mm. long 
Spikelets 6 to 8 mm. long 
Culms erect. 
cee ee eee eee ee ee eee 41. P. altum. 
wee cece ee eee eee eee 42. P. havardii. 
Panicles elongate, strongly contracted; seacoast 
wee eee ee eee eee 43. P. amarulum. 
Panicles diffuse or only slightly contracted; plants 
sometimes of salt marshes but not littoral. 
Panicles open, loosely-flowered; spikelets 3.5 to 
5 mm. long, beaked; first glume two- 
thirds the length of the spikelet or more, 
acuminate-pointed..................24 39. P. virgatum. 
Panicles somewhat contracted; spikelets not 
over 3.2 mm. long, not beaked; first 
glume about half the length of the spike- 
let, not acuminate 
cence eee eee eee ee eee ee 39a. P.virgatum 
cubense. 
37. Panicum repens L. 
Panicum repens L. Sp. Pl. ed. 2. 87. 1762; Contr. U. S. Nat. Herb. 15: 85. 1910. 
Fig. 51.—Distribution of P. repens. 
DISTRIBUTION. 
Sea beaches, warmer regions of both 
hemispheres; in America from Ala- 
bama to Brazil. Originally described 
from the Old World. 
Nicaracua: Without locality, 
Flint 8. 
Cusa: Arroyo Apold, Ledn 296, 
563. Habana, Ledn in 1909. 
