40 



Bciitlmni .1- ll<).)l<(<r iii(lu<l<' fiiMlinnm iin.lrr I'rnrrihnnin, iiltliougli (l,o 

 I'liiit cluimctcrs are fiuiLo distinct and almost identical witli tliohso of //rr- 

 (iclritin. In comparison with I'cncitliinitin, the fruit of I'uHtiniivn is miicli 

 more dorsaily flattened, the lateral wings are nerved towards the outer 

 margin, and a remarkable lay(!r ol strengthening cells invests the seed- 

 cavity (instead of occurring in small isolated groups beneath eacli rib); all 

 of which characters it shares with Hmu-leum. The length of the oil- 

 tubes, a character stimetimes used, is (juite variable. \\\ I'linliiiucit Yh'iw^ 

 sometimes as long as the fruil and sometimes shorter. 



P. SA ii\ A L., the common piiisnip, is iiiliochiccil almcjst 

 cvciAwiicre. The leallcts arc ()\ ate to ohloiii;-, and ciit-toolhcd. 

 (Fig. 21).) Fl. July to September. 



1:5. POLYT.FMA DC. Mem. Uml)cl. :^^. -Feremiial 

 mostly i^lalirous herbs, with twice pinnate lca\es, no iinohicre, in- 

 vohiccls of narrow bractlcts, and brii^lit vellow Howcrs. 



1. P. Nuttallii DC. I.e. Two to tliree feet hi-h, mostly 

 glabrous except the pubescent peilicels anil in\'olucels: leaf-seg- 

 ments cuneate and incised; upper leaves opposite and 8-cleft: 

 umbel 6 to 12-rayed; rays about an inch long; pedicels 1 or 2 lines 

 long: fruit 8 to 5 lines long, (Fig, 80.) 



Barrens, Wisconsin (Lapliam), S. Michigan i Wrinlil, Crdi/), and Indi- 

 ana (C/rt7)y»), to Kentucky (Short), Tennessee (O'ltltinncr), N.Alabama 

 yBticklei)), and Louisiana, westward to the Rocky Mountains. 



U. COLOPTFRA.— Dwarf sandy ground plants, with 

 small leaves (lobed, simply pinnate, or bipinnate), no involucre, 

 involucels of foliaceous more or less unite<l bractlets, and mostly 

 yellow flowers. 



The whole habit of this geiuis is very peculiar. The thick corky laLeiai 

 wings of the fruit arc those of Leptolivniu, while the freciuent winging of 

 dorsal and intermediate ribs approaches ('umoplerux. It seems therefore 

 somewhat to combine the characters of these two genera in its fruit, while 

 in habit it more nearly approaches some species of ('nuKiplerus. Such 

 combination of characters is to be found in no genus, and therefore we pro- 

 j)Ose a new genus to contain the three tollowiug species: 



1. C. Newberryi. Acaulescent, 2 to inches high: leaves 

 ovate l(» oblong in outline, 1 to 2 inches long, shorter than the 

 petioles, pinnately 8 to 5-foliolatc or simjjly lobed; terminal leaflet 

 8-lobcd, the lower mostly 2-lobed, all the lobes sparingly incised : 

 umbel une(|ually i to 10-ra\ed, with conspicuous involucels of \ei\- 



