TETRANDRIA. MONOGYNIA. 95 



form, 4-cleft. Capsule S-celled, many-seeded, 

 half superior, opening transversely. 



Flowers terminal, rarely axillary; stem dichotomous, 

 mostly quadrangular. 



Species, i. H. patens. El. (pttsilla.) The smallest 

 and earliest flowering species of the genus. Leaves pe- 

 tiolate, ovate, acute, margin and angles of the stem a 

 little scabrous; segments of the corolla short, rounded, 

 obtuse. 0, 1 to 2 inches high. Flowers saturate blue. 

 2. ccerulea. Smootn; radical leaves ovate, spathulate; stem 

 dichotomous, peduncles 1-flowered, very long; segments 

 of the corolla oblong oval, with acute points. S serpylli- 

 folia. 4. teJiella^PvRSH. S . rotmidifolia. Peduncles axillary. 

 6. longifoliay {H. ang-ustifolia, Mich.) 



7. *te?ii(ifolia. Smooth; stem erect, divaricate, extreme- 

 ly branched; leaves very narrow and linear; ramtili sub- 

 trichotomous, flowers terminal, subfastigiate, corymbu- 

 lose, long and setaceously pedunculate. 



Stem about 6 inches high, dichotomously subdivided 4 

 or 5 times. Leaves an inch long, scarcely a line wide, 

 nearly of an equal breadth, and somewhat acute. Pe- 

 duncles setaceous, from half an inch to 1 inch long, 1 to 

 3 and 4-flowered Calix 4-cleft, setaceous Flowers small. 

 — Near the confluence of Pidgeon river, and the French 

 Broad, Tennessee, on dry gravelly hills. 



8. purpttrea. Flowers subcampanulate, stamens exsert- 

 €d beyond the tube of the corolla 



With the exception of the splendid Houstoma coccinea, 

 of VIexico, this genus is thus far confined to the United 

 . States. 



137. POLYPREMUM. L. 



Calix 4 parted. Corolla 4-cleft, rotate, beard- 

 ed at the orifice. Stamina included. Capsule 

 compressed, 2-celled, many-seeded. 



Herbaceous, erect, or procumbent, dichotomous; leaves 

 opposite, menibranaceously connate; flowers small, di- 

 chotomal and terminal, each surrounded by a bracteal 

 involucrum. 



Species. 1. P. procumbens. A genus consisting* of 

 but a Single species, peculiar \o the United States, and 

 extending from Virginia to the Gulf of Mexico; nearly al- 

 ^dlied to Uoustoniat diflering principally in habit. 



