TUIANDRIA. DIGYATLA. 79 



calix bluish-purple, exterior valve lanceolate, mucronate* 

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

 hairs arisnig- from so many tubercles; inner valves shorter, 

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

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

 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 the pre- 

 ceding, is very considerably allied to Chloris, appearing 

 to unite that genus and Seslerio, agreeing partly with the 

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

 in its habitus. ( .\ North American genus.) 



111. MONO CERA. Elliott, 



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 obtusely 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, a\\nless, the lowest neutral 

 flower sessile, with a long awn: herrnaphrodite 

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

 valves awned; awi.s 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- 

 duhferous; 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 Anthoxanthwn 

 odoratum, Holciis odoratns, &c.) 



Species. \. J\I. aromatica. ( Chlons monostachya. Mich. 

 l.p.59) 



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-valved, attached to a callous tubercle at its 

 base; outer valve oblong-lanceolate, mucronate, a httle ob- 

 lique, obtusely cai-inate, 3-nerved, with a broade;- mexa- 



