95 CLASS XVIII. ORDER IV, 



choke) lower leaves heart-ovate, root tuberouSr 



%' y. 



Coreopsis. Calyx double, also many-leaved : 

 seeds compressed, emarginate : receptacle chaffy : 

 egret 2-horned. 49. 55. — verticillata^ (tickseed sun- 

 flower) leaves pinnate three or five in a whorl. If.. 

 Av. — trichosfterma, pinnate leaves with 5 or 7 leafets, 

 seed wedge-form. y. — auriculata, leaves ovate en-? 

 tire, lower ones ternate. %. y. 



Centaurea. Calyx various, mostly imbricate, 

 roundish : egret simple, various : receptacle brist- 

 ly : corols of the ray funnel-shaped, longer, irregu- 

 lar. 49. 54 — cyanus, (blue-bottle) leaves linear en- 

 tire lower ones toothed, ©.b.e. — jacea, leaves lance- 

 olate entire, radical ones a little toothed. %. b.— 

 beiiedicta^ (blessed thistle) leaves sub-decurrent, 

 calyx with branchy thorns. — centaureum^ (tall blue- 

 bottle) leaves pinnate, leafets doubly-serrate, e.' 



Order IV. Poltgamia Necessaria. 



SiLPHiuM. Calyx squarrose, scales leafy, broad : 

 egret S-horned-margin : receptacle chaffy : seeds 

 compressed, obcordate, margined. 49. 55 — fierfolia' 

 ium^ (ragged cup) leaves opposite connate, stem 3- 

 sided. Il.y.'-'ternatum^ leaves in threes near the 

 middle of the stem, panicled. l^y. 



PoLYMNiA. Calyx double, exterior 4-5-leaved, 

 interior 10-leaved, leafets concave : egret : re- 

 ceptacle chaffy. 49. 5 5 — canadensis^ (leaf-cup) 

 leaves denticulate, lower ones pinnatifid. %. w.— - 

 iivedaUQf leaves 3-lobed. IJ.. y. 



IvA. Calyx 3-leaved : styles 2, long : seed na- 

 ked, obtuse : receptacle hairy : ray 5-flowered. 49. 

 SS^-frutescens, (highwater shrub) leaves lanceo- 

 late rough-dotted deep-serrate. >2 . §;. 



