' DIDYNAMIA, GYMNOSPERMIA. 35 
Species. 1. O. vulgare. Indigenous.—A genus of 
about 17 species almost exclusively indigenous to the Le- 
vant; of these O. Tournefortii is one of the rarest and most 
local plants in the world. : 
412, DRACOCEPHALUM. LE. (Dragon’s head.) 
Calix subequal, 5.cleft. Orifice of the corol- 
la inflated; upper lip concave. Stamina uncon- 
nected. 
Herbaceous or rarely suffruticose; flowers verticillately 
spiked and terminal, or axillary, peduncles one or many- 
flowered, bracteate; bractes broad, sometimes ciliate, in 
most of the American species very small. 
Spectres. 1. D. variegatum. 2. virginianum. 3. denti- 
culatum. 4.* cordatum. Stoloniferous; stem and elonga- 
ted petioles pubescent; leaves cordate, obtusely crenate, 
upper side a little hirsute; spike unilateral; icells bi- 
bracteolate; bractes of the rachis nearly as long as the ca- 
lix, broad-ovate, entire. Oss. Root creeping, perennial, 
fibrous. Stem stoloniferous after flowering, scarcely a 
foot high, quadrangular, subpilose. Leaves about 3 or 4 
pair, almost as broad as long, obtusely cordate, smooth be- 
neath, petiole the length of the lamina (about an inch, ) up- 
permost pair of leaves subsessile. Bractes unusually large, 
peduncles short and thick, mostly 1-flowered. Flowers se- 
cund. Calix submembranaceous, nearly equal, partly 
campanulate, segments acute, almost pungent. Corolla 
pale blue, about an inch long, and larger than that of D. 
irginianum; orifice much dilated; upper lip concave, ob- 
tuse, and emarginate, lateral teeth of the lower lip conspi- 
cuous; central segment rounded, pilose, and elegan’ 
spotted. Receptacle of the seed large, many of the 
seeds abortive. Has. On the shady islands of the Ohio, 
about 40 miles below Pittsburgh; flowering in June. The 
whole plant, but more particularly the flower, possesses 
an agreeable balsamic aroma, considerably like that of 
the Balm of Gilead (D. canarienze) but in an inferior de- 
5. * parviflorum. Flowers, verticillate, subcapitate; 
leaves ovate-lanceolate, deeply serrate, and petio- 
late, bractes foliaceous, ovate, ciliate, and serrate, ser- 
ratures conspicuously mucronate; upper segment of the 
calix much larger than the rest; flower lor 
than the calix. Has. Around Fort Mandan, 
ouri; on the borders of thickets. Oxs. Bie 
