SPIGELIA. LXXII. RUB1ACEJE. 307 



with the calyx ; seeds 2, peltate, furrowed on the face. Mostly her- 

 baceous and tropical. Fls. small, axillary, sessile, whorled, 



S. GLABRA. Michx. 



Glabrous, procumbent at base; Ivs. opposite, lanceolate, entire; whorls 

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

 throat ; anthers included in the tube ; stig. subsessile. River banks, Western 

 States ! Stem 1 2f long, terete, with 4 prominent lines, branched. Leaves 

 2 3/ by |. i/ } tapering to each end. Flowers white, 8 20 in a whorl, sub- 

 tended by the subulate bracts of the stipules. Jl. Aug. Resembles some of 

 the Labiatse. 



5. DIODIA. 



Or. Jif, twice, odovs, tooth ; alluding to the two calyx teeth crowning the ovary. 



Calyx, corolla, stamens, style and fruit, as in Spermacoce, except 

 that the (2 or 3) 1 -seeded, separable carpels are both indehiscent ; 

 seeds oval, peltate. American, chiefly tropical herbs, ivith the habit of 

 Spermacoce in all respects save the indehiscent carpels. 



1. D. VIRGINIANA. (Spermacoce. A. Rich.} 



Procumbent, nearly glabrous or hirsute ; Ivs. lanceolate-linear, sessile, 

 entire ; bristles of the stipules longer than the sheaths ; As. solitary, opposite ; co- 

 rolla, tube thrice longer than the calyx ; sta. exserted ; sty. deeply 2-cleft, the 

 lobes filiform. 1\. Damp places, 111. to Ga. ! and La. Stem 1 2f long, some- 

 what 4-sided. Leaves 1 2' by 2 4", 1-veined, often with smaller ones fasci- 

 cled in the axils. Corolla 5" long, hairy inside. May Sept. 



2.. D. TERES. Walt. (Spermacoce diodina. Michx.} 



Procumbent or ascending, hairy or scabrous ; Ivs. linear-lanceolate, sessile, 

 rough-edged, acute, much longer than the sheaths or fruit ; fls. solitary or several 

 in each axil ; cor. funnel-form, with a wide tube, twice longer than the calyx ; 

 fr. somewhat hairy and 4-sided. Sandy fields, N. J. to 111. Mead ! and South- 

 ern States. Stems rather rigid, much branched, 5 18' long, brownish. Leaves 

 about 1' by 2". Corolla reddish-white, shorter than the reddish-brown bristles. 



6. CEPHALANTHUS. 



Gr. Kedtahr), ahead, avSos, a flower; flowers growing in dense heads. 



Calyx limb 4-toothed : corolla tubular, slender, 4-cleft ; stamens 4 ; 

 style nmch exserted. Shrubs with opposite leaves and short stipules. 

 Fls. in globose heads, without an invol. 



C. OCCIDENTALJS. Button Busk. 



Lrs. opposite, and in 3s, oval, acuminate, entire, smooth ; hds. peduncu- 

 late. A handsome shrub, frequenting the margins of ponds, rivers and brooks, 

 U. S. and Can. It is readily distinguished by its spherical heads of flowers, 

 which are near 1' diam., resembling the globular inflorescence of the sycamore 

 (Platanus occidentalis). Height about 6f. Leaves spreading, entire, 3 5' by 

 2 3'. The flowers are tubular, with long, projecting styles, and are inserted 

 on all sides of the round receptacle. July. 



SUBORDER 3. S PIGEL.IEJE. 



Calyx persistent, almost entirely free from the ovary. Leaves oppo- 

 site, with intermediate stipules. 

 7. SPIGELIA. 



In honor of Adrian Spigelius, Prof, of Anat. and Surg. at Padua, 15781625. 



Calyx 5-parted, segm. linear-subulate ; cor. narrowly funnel-form, 

 limb 5-cleft, equal ; stam. 5 ; anth. convergent ; caps, didymous, 2- 

 celled, few-seeded. Herbaceous or suffrutescent. Lvs. opposite. Stip- 

 ules small, interpetiolar. Fls. sessile, in terminal spikes. 



