CHLORIDES. 437 



Arizona, Pringle in 1884. 



11. L. dubia (11. V,. K.) Nees, Syll. Ratisb. 1:4 (1824); Agrost. 

 Bras. 2:433 (1829). Chloris dubia H. B. K. Nov. Gen. et Sp. 1: 

 161) (1815). D. dubia Scribn. Bull. Torr. Chib, 10:30 (1883). 



Culms rather slender, 20-30 cm. high. Sheaths smooth or sca- 

 brous; ligule very short, bearing long hairs; blades scabrous, flat or 

 involute, 20-40 cm. long, 3 mm. wide. Panicle barely exserted, 

 15-20 cm. long, siDikelike, ra3's 8-15, ascending, 5-12 cm. long. 

 Spikelets on short pedicels, slightly imbricate, 4-6-flowered, 5-7 

 mm. long; empty glumes lanceolate, 1-nerved, first 3-4 mm. long, 

 second 4-5 mm. long; floral glume ovate-oblong, about 4 mm. long, 

 the three nerves pubescent and disappearing a little below the two 

 obtuse lobes of the apex; palea linear, 3.5 mm. long, the nerves 

 densely clothed with short pubescence. 



Florida, Curtiss 3450, Garber; Texas, Jones, Nealley ; Arizona, 

 Lemmon 368; Mexico (Chihuahua), Pringle 422, Palmer for U. S. 

 Dept. Agricul. 547, Palmer 270. 



Dr. Palmer says: "In shady places among the rocks of the 

 mountains."' 



12. L. Mexicana Scribn. Proc. Acad. Phil. Sc. 308 (1891). 

 Culms simple, terete, solid, erect, 1 mm. or more high from a 



strong rootstock. Sheaths about the length of the internodes, lig- 

 ule a ring of stiff hairs, 2-3 mm. long; blades glabrous, flat, lanceo- 

 late, 30-40 cm. long, 1-2 cm. broad, tapering gradually to the 

 very acute apex, midrib white and prominent below. Panicle 

 pyramidal, 30-40 cm. long; rays sim2)le solitary or the lower sub- 

 verticillate. Spikelets 10-14 mm. long, 3-4-flowered, erect, remote 

 below; pedicels mostly shorter than the spikelets; empty glumes 

 membranaceo-chartaceous, broadly lanceolate, first 4-5 mm. long, 

 second 6-7 mm. long, scabrous on the nerve; floral glume 8 mm. 

 long, densely silky-villous for half or more of its length, mid-nerve 

 extending into an awn 1-3 mm. long beyond the entire apex, lateral 

 nerves evanescent above; palea 2-toothed, callous, densely pilose. 

 Stamens 3. Ovary smooth. 



Mexico, Pringle 3252, on limestone ledges. 



13. L. polygama (Fourn.). Gouinia polygama Fourn. Hemsl. 



