DIDYNAMIA, GYMNOSPERMIA. 27 



A genus of about 25 species almost exclusively Euro- 

 pean, yet exiending- to India and the Cape of Good Hope. 



597. ISANTHUS. MichcPlix. 



Calix subcampaiiulate. Corolla 5-partetI; 

 tube straight and narrijw; segments of the bor- 

 der ovate and equal. Stamina subequal. Stig- 

 mas linear, recurved. 



Annual, covered with a viscid pubescence, leaves en- 

 tire, longitudinally nerved, flowers axillary and peduncu- 

 late, greyish-blue, calix becoming xruginous. 



Species. 1. T. cceruleus. Trichostema brachiaia. L. 

 Hab. In Pennsylvania, Maryland and Virginia, but more 

 abundant west of the mountains, from whence it appears 

 to have originally propagated along the Ohio and the Mis- 

 sissippi as well as part of the Missouri. — The only spe- 

 cies. Seeds reticulately rugose as in Tricho sterna to 

 which this genus is somewhat allied. 



398. HYSSOPUS. L. (Hysop.) 



Lower lip of the Corolla 3 -parted, interme- 

 diate segment subcrenate. Stamina straiglit, 

 and distant. 



A very unnatural genus of about 5 or 6 species; flowers 

 in B. officinalis axillary and verticillatc; corolla in H. Lo- 

 phanihus resupinate with the flowers partly cymose; the 

 American species scarcely distinct from JVepeta, are tall 

 plants with cordate-ovate toothed leaves, and dense ter- 

 minal verticillated spikes, with white or pale blue flowers. 



Species, 1. H. nepetoicles. Bractes dilated; calix 

 smooth, segments linear. 2. scrrjphularicefolius. Bractes 

 ovate acute; calix smooth, segments subovate. 3. * ani- 

 satus. Smooth; spikes verticillate interrupted; leaves cor- 

 date-ovate, angularly toothed, under side glaucous; calix 

 equal, acute, pubescent, segments subovate, about one third 

 the length ol the calix; bractes scarcely as long as thepe- 

 dicells. Stachi/s Feeniculum, Ph. Hab. On the plains of 

 the Missouri near Fort Mandan, on the borders of thick- 

 ets. Obs. 2 or 3 feet high, very smooth; leaves petio- 

 late, about an inch long, acute, no where tomentose, but 

 whitish or glaucous on the under side and covered with 

 . resinous punctures, w hich when bruised emit an agree- 

 able aniseed odor; spikes short and interrupted; flowers 



