SYNGENESIA— POLYGAMIA-ZEQU. Bideiis. 399 



Common Cal. erect, of several oblong, nearly equal, parallel 

 scales, concave, or channelled, at the back. Cor. com- 

 pound, of several, parallel, level-topped, perfect, tubu- 

 lar, regular and e(\uix\Jlorets ; their limb ovate, with 5 

 marginal, spreading segments. Tilam. from the tube, 

 capillary, very short. Anth. in a cylindrical tube, 

 slightly prominent. Germ, oblong, compressed, with 2 

 or more bristly upright points, about equal to the tube 

 of the floret, on its outside. Stijle thread-shaped, within 

 the tube. Stigmas oblong, spreading beyond the an- 

 thers. Seed-vessel none but the unaltered close calyx. 

 Seed compressed, abrupt, angular, rough at the edges, 

 and beaked with 2 or more bristles, rough with minute 

 reflexed prickles. Recept. flat, beset with upright, chaffy, 

 oblong, deciduous scales as tall as the florets. 



Most species are occasionally liable to acquire marginal ra- 

 diant ?evi\]Q JloretSy destitute o^ stamens, which consti- 

 tutes the character of Coreopsis. Such a change is nearly 

 analogous to becoming double in the generality ofjfoivers, 

 and is not, as some have thought, a more perfect state 

 of the compound tribe, but rather the contrary. 



Herbaceous, mostly annual, upright plants, with opposite, 

 simple or compound, lobed or serrated leaves. Fl. stalk- 

 ed, somewhat corymbose, erector drooping, terminal or 

 axillary, the base of the calijx encompassed with a circu- 

 lar row of spreading leafy bracteas ; disk yellow ; the xix.- 

 diantjlorets, when they occur, are in some species white. 



Willdenovv considers the bracteas as an outer calyx, in 

 which he may perhaps be correct. 



1. ^.tripartita. Three-lobed Bur-marigold. 



Leaves in three segments. Bracteas unequal. Bristles of 



the seeds two or three, erect. 

 B. tripartita. Li«H. S/5. P/. 1 165. fFiZW.u. 3. 1715. F/. Br.858. 



Engl. Bot.v. 16. /. 11 13. Curt. Lond.fasc. 4. t. 57. Hook. Scot. 



238. 

 B. n. 121. Hall. Hist. V. 1.51. 

 Verbesina, sen Cannabina aquatica, flore minus pulchro, elatior 



et mag]s frequens. RcdiSi/n. 187. Bauli. Hist, v, 2. 1073. 

 Chrysanthemum cannabinum bidens, folio quinquepartito, sive 



vulgare. Moris, u. 3. 1 7. sect. 6. t. 5./. 20. 

 Eupatorium cannabinum foemina. Ger.Em.7ll.f. Lob. Ic. 529./; 



bad. 

 Hepatorium aquatile. Dod. Pempt. 505./. 

 Hydropiper alteram. Dalech. Hist. 1039./. 



