TETRANDRIA. MONOGYNIA. 95 



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

 half superior, opening transversely. 



Flowers terminal, rarely axillary; stem dichotomous, 

 mostly quadrangular. 



Species. 1. ff. patens^ El. {pvsilla.) The smallest 

 and earliest flowering' species of the genus. Leaves pe- 

 tiolate, ovate, acute, marg-in 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. caerulea. Smootn; radical leaves ovate, spalhulate; stem 

 dichotomous, pt-duncles 1-flowered, very long; segments 

 of the corolla oblong oval, with acute points. 3. serpyllU 

 folia. 4. tenella^PvnsH. 5.roUmdifolia. Peduncles axillary. 

 6. long-ifoliaf (H. ang-iistifoUa, Mich.) 



7. *ten'afolia. Smooth; stem erect, divaricate, extreme- 

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

 trichotomous, flowers terminal, subfastigiate, corymbu- 

 !ose, long and seiaceously 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. 



S. purpurea. Flowers subcan'panulate, stamens exsert- 

 ed beyond the tube of the corolla 



With the exception of the splendid Houstonia cocchiea, 

 of Mexico, 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, t^tamina included. Capsule 

 compressed, 2-celIed, many-seeded. 



Herbaceous, erect, or procumbent, dichotomous; leaves 

 ©pposite, membranaceoush connate; flowers small, di- 

 chotomal and terminal, each surrounded by a bracteal 

 involucrum. 



Species. 1. P. prociimbens. A genus consisting of 

 but a single species., peculiar lo the United Statfs, and 

 extendmg from Virginia to the Gulf ot Mexico; nearly al- 

 allied to JSoustoniUi differing principally in habit. 



