GENERA OF GRASSES OF THE UNITED STATES. 133 
Coleanthus subtilis (Tratt.) Seidel (fig. 71), introduced from 
Europe, grows on mud flats along the Columbia River, where it was 
collected by Howell (on Sauvies Island, Oreg.) and by Suksdorf 
(western Klickitat County, Wash.). 
Mibora minima (L.) Desv. has been found at Plymouth, Mass. 
This, the only species of the genus, is a low annual, differing from 
Coleanthus and Phippsia in having glumes longer than the lemma, 
the very small spikelets in simple spikes. Introduced from Europe. 
59. Cinna L. 
Spikelets 1-flowered, disarticulting below the glumes, the rachilla 
forming a stipe below the floret and produced behind the palea as a 
minute bristle; glumes equal, 1-nerved; lemma similar to the glumes, 
Fic. 71.—Coleanthus subtilis. Plant, X 1; lemma and palea and two views of spikelet 
with ripe caryopsis, xX 20. 
nearly as leng, 3-nerved, bearing a minute, short, straight awn just 
below the apex; palea apparently 1-nerved, 1-keeled. 
Tall perennial grasses, with flat blades and paniculate inflorescence. 
Species three, North America and northern Eurasia, two in the 
United States and one in Mexico and southward. 
Type species: Cinna arundinacea L. 
Cinna L., Sp. Pl. 5, 1753; Gen. Pl., ed. 5, 6 1754. <A single species is 
described. 
Abola Adans., Fam. Pl. 2: 31, 511. 1768. Based on ‘ Cinna Lin.” 
Cinnastrum Fourn., Mex. Pl. 2:90. 1886. Two species are given, C. miliaceum 
and ©. poaeforme, both referable to Cinna poaeformis (HH. B. K.) Scribn. and 
Merr. 
The prolongation of the rachilla is less than 0.5 mm. in our 
species, but in Cinna poacformis of Mexico it is half as long as the 
palea. The palea is 1-nerved in C. arundinacea. In C. poaeformis 
the 2 nerves are close together but distinct. In (@. latifolia the palea 
is apparently 1-nerved, but the 2 nerves separated when the palea is 
split along the keel. 
