1889.] BOTANICAL GAZETTE. H9 



** Wings narrow, involute and very thick ; pappus minute or none. 



C. auriculata L. is well marked by its achenia, although 

 it resembles C. pubescens very much in its vegetative char- 

 acters, under which species it was placed by Torrey & Gray. 

 The achenia are very smooth, a line long by half line broad, 

 tuberculate, incurved ; wings narrow, involute and thickened, 

 making the achenium boat-shaped. (Fig. 16 « and 0.) 



Fig. 16 a is the back view of an achenium, and 166 the 

 front view, the inner ring being the thickened involute mar- 

 gin. Drawing from Curtiss's Virginia collection. 



§ 3. Achenia oblong, often villous-ciliate, with no callus on inner lace, 



not papillose -roughened. 



* Achenia with narrow wings, flat and smooth. 



The first five species, belonging to § Eucoreopis, form a 

 •closely related group, and though generally easily sepai atea 

 by leaf characters the fruits vary but little. They all have 

 small achenia, which are more or less incurved, with narrow 

 scarious wings and small or obsolete awns. 



C. falmata Nutt. Achenia oblong, with narrow wings 



and obsolete awns. (Fig. 17.) . . 



C. verticillata L. has oblong to obovate-cuneiform achenia 



witH" minute awns. (Fig. 18.) , 



C. delfhinifolia Lam. has achenia somewhat broader than 

 the last, from which it can not well be separated upon truit 



characters alone. (Fig. 19.) ,. .. . 



C. senifoUa Michx. is much like the Preceding, but the 

 achenia (2 lines long) are not so narrow at base, oblong or 

 elliptical in outline, and awnless. (Fig. 20 ) , •„ 



A specimen collected bv Dr. and Mrs Bntton has achenia 

 H lines long and 1 * lines broad. In 1885 the same botamsti 

 collected at Black Mt. Station a form which is probably rwnat 

 Elliott described as C. CEmleri, but which Dr. ("*£■" 

 Synopt. Flora, considered the "abnormal entire-leaved foi m 



of C. senifolia var. stellate. It does not accord well wit* tthe 



form examined, and seems to approach forms of U tnptens. 

 The achenia are more oval than in C. semlolia. 



C.triperisl*. Achenia obovate, broader than the pre- 

 ceding, emarffinate at apex. (Fig- 2I -) „ . r T Q^Q 



r\ • P t> c t C* Vnrter s collection ot 1000. 

 Drawino- from Prof. 1. v-" r^oriei & ^ucu 



** Achenia wingless, somewhat angled, often ciliate on margin. 



distinguished from it 



• A 1 _ — — - 



lati folia M 



re- 



latecT species by fruit characters as vegetative. Achenia tf 



