TRIANDRIA. DIGYNIA. 79 



calix bluish-purple, exterior valve lanceolate, mucronatt' 

 with a single nerve; the nerve beset with a few scattered 

 huirs arising from so many tubercles; inner valves shorter, 

 very narrow. Corolla, outer valve lanceolate, carinate, 3- 

 awned, pilose along the margins of the nerves, and at the 

 base; inner valve smoo'.h, shortly bi-cuspidate. Neutral 

 flower 1-valved, obtuse, with 3 awns, and pubescent at 

 the base. 



This species, though certainly a congener of tl^e pre- 

 ceding, is very considerably allied to Chloris, appearing 

 to unite that genus and Sesleria, agreeing partly with the 

 latter in the structure of the flowers, and with the former 

 in its habitus. ( A North American genus.) 



111. MONOCERA. EllioU, 



Flowers polygamous, disposed by 2 rows, in 

 an unilateral pectinate spike. — Calix 2-valved, 

 rigid, fixed, many-flowered; valves unequal, the 

 inner very small, the outer obtu.sely carinate, 

 and cuspidate, sending out an horizontal awn 

 above the middle, tuberculate at its base. Flow- 

 ers within the common calix, 3 to 4, neuter, 

 and 1 hermaphrodite; the upper neutral rudi- 

 ments pedicellate, awnless, the lowest neutral 

 flower sessile, with a long awn: hermaphrodite 

 2-valved, with a Sd. accessory valve, dorsal 

 valves awned; awns all arising below the sum- 

 mit, unequal, and erect. 



Culm pubescent, erect, and solid, terminated by a sin- 

 gle recurved, appressed spike; calix smooth, nerves glan- 

 dul.ferous; corolla membranaceous, sessile flowers villous 

 at the base and midway along the margin, awned from 

 below the summit. The whole plant' aromatic when 

 bruised; aroma gramineous, (resembling Anthoxanthum 

 odoratum, Holciis odoratns, &c.) 



Species. 1. Jf. aromatica. ( Chloris monostachi/a, Mich. 



i.p.sy) 



Culm terete, 3 to 4 feet high. Leaves long, glabrous 

 below, scabrous above; stipules hairy. Spike terminal, 

 solitary, one-sided, spikelets opposite, in 2 rows. Rachis 

 semi-cylindric, margined; receptaculum grooved. Calix 

 rigid, fixed, 2-vaived, attached to a callous tubercle at its 

 base; outer valve oblongdanceolate, mucronate.a little ob- 

 lique, obtusely carinate, 3-iierved, with a, broader mem- 



