402 OBDEB G7.-RTJBIACE.jE. 



6. DIO'DIA L. (Gr. 61$, twice, bdovq, tooth, alluding to the two 

 cftlyx teeth crowning the ovary.) Calyx, corolla, stamens, style and 

 fruit as in the next genus (Spermacoce) except that the (2 or 3) 1 -seeded, 

 separable carpels are in both indehiscent ; seeds oval, peltate. American, 

 chiefly tropical herbs. Slip, fringed with bristles. Fls. small, white, 

 axillary, sessile, solitary or few. 



1 D. Virginiana L. Procumbent, nearly glabrous or hirsute; sts. squarish ; lv* 

 lanceolate, sessile, entire ; bristles of the stip. longer than the sheaths ; fls. soli- 

 tary, opposite; cor. salver form, tube very slender, thrice larger than the cal. ; 

 stam. exserted; style deeply 2-cleft, lobes filiform. If Damp places, 111. to Ga. 

 and La. St. 1 to 2f long, somewhat 4-sided. Lvs. 1 to 2' by 3 to 5", 1-veined, 

 often with smaller ones fascicled in the axils. Cor. 6" long, hairy inside. May- 

 September. 



f3. has ovate-lanceolate Ivs. (D. tetragona Walt.) 

 . y. has lance-linear, hairy Ivs. ; cor. 6" long. May Sept. (D. hirsuta Ph.) 



2 D. teres Walt. Erect or ascending, hairy or scabrous ; Ivs. linear-lanceolate, 

 sessile, rough-edged, acute, much longer than the eheaths or fruit ; fls. solitary, or 

 several in each axil ; cor. funnel-form, with a wids tube, twice longer than the cal. ; 

 fl. somewhat hairy and 4-sided. Sandy iields, N. J. to 111. (Mead) and S. States. 

 Sts. rather rigid, simple, or branched, 5 to 18' long, brownish. Lvs. about 1' by 

 .2". Cor. reddish white, shorter than the reddish brown bristles. Aug., Sept 

 (Spermacoce diodina MX.) 



7. SPERMACO V CE, L. (Gr. arrKp^a^ seed, aKW/C7y, a point ; alluding 

 to the pointed seeds.) Calyx .tube ovoid, limb 2 to 4-parted ; corolla 

 tubular, limb spreading, 4-lobed ; stamens 4 ; stigma 2-cleft ; -fruit dry, 

 2-celled, crowned with the calyx, separating into 1 open and 1 indehis- 

 CQnt carpel ; seeds 2, peltate, furrowed on the face. Mostly herbaceous 

 and tropical. Fls. small, in dense, axillary, sessile whorls, or clusters. 



1 S. glabra MX. Glabrous, procumbent at baso ; Ivs. lanceolate, entire ; whorls 

 many-flowered ; cal. 4-toothed (rarely 5) ; cor. funnel-form, short, hairy in the 

 throat ; anth. included in the tube j stig. subsessile. 2 River banks, W. States. 

 St. 1 to 2f long, terete, with 4 prominent lines, branched. Lvs. 2 to 3' by J to 1', 

 'tapering to each end. Fls. white, 9 to 20 in a whorl, subtended by the subulate 

 bracta of the stipules. JL, Aug. Resembles some of the Labiate. 



2 S. Chapmnii Torr. & Gr. Nearly glabrous; St. slightly 4-angled; Ivs. ob- 

 long-lanceolate, attenuate to a petiole ; whorls dense-flowered ; cor. funnel-form, 

 thrice longer than the cal. ; stam. and slender sty. exserted. River banks, Mid. 

 ll'la. (Chapman.; 



8. HOUSTCTNIA, L. BLUETS. (Dedicated to Dr. Win. Houston, 

 the friend and correspondent of Miller.) Calyx tube ovoid-globous, 

 Kmb 4-toothed or-cleft, persistent ; corolla tubular, much exceeding the 

 calyx ; limb 4-lobcd, spreading ; filaments 4, inserted on the corolla ; 

 style 1 ; anthers and stigmas dimorphous, that is, in some plants, the 

 former exserted and the latter included, in others the style exserted and 

 anthers included ; capsule 2-lobed, the upper half free, cells few (8 to 

 20)-seeded. Herbs. Stip. connate with the petiole, entire. Fls. soli- 

 tary or in cymes, white, purplish, or bluish. 



Corolla salver-form, glabrous. Peduncles 1 -flowered terminal Nos. 1, 2 



-axillary -.Nos 3,4 



Corolla funnel-form. Peduncles 00 -flowered, cymous. Leaves lance-ovate No. 5 



Leaves lance-linear Nos. 6, T 



1 H. coeriilea L. DWARF PIN T K. INN T OCEKOE. Osespitous ; radical Ivs. ovate- 

 spatulate. petiolate ; sts. erect, numerous, dichotomous ; ped. filiform. 1 to 2-flow- 

 ered. ;g) An elegant little plant found in moist grounds, fields, and road-sides, 

 Canada and U. S., often in patches. C;xuline Ivs. very small, opposite, lance- 



