158 



A NEW GENUS OF NORTH AMERICAN 

 UMBELLIFERAE 



By Kenneth K. Mackenzie 



While botanizing last August on Kate's Mountain near White 

 Sulphur Springs, West Virginia, I noticed a plant which I took 

 to be Taenidia intcgerrima (L.) Drude. As this is a common 

 plant I did not make any specimens at the time. A few days 

 later, however, on another part of the same mountain I saw an- 

 other plant, which also seemed to be Taenidia intcgerrima but 

 the fruit of which did not correspond to my recollection of the 

 fruit of the first plant. This led me to investigate and get 

 specimens of both plants. When put side by side the difference 

 in the fruits was at once noticeable. In fact the fruits represent 

 two very widely separated types of umbelliferous fruits, and are 

 almost as distinct from one another as two umbelliferous fruits can 

 well be, but outside of the fruits the two plants are apparently 

 identical. The second plant discovered proved to be genuine 

 Taenidia intcgerrima (L.) Drude, and the first I venture to char- 

 acterize generically and specifically as follows : 



Pseudotaenidia gen. nov. 



Glabrous and glaucous erect perennials from stout horizontal 

 to perpendicular rootstocks. Leaves ternately decompound, the 

 leaflets entire. Umbels borne on terminal and lateral peduncles, 

 compound, the rays very unequal in length. Involucre and in- 

 volucels none or rarely of one or two bractlets. Corolla not 

 seen.* Calyx-teeth short, but evident. Fruit thick, strongly 

 flattened dorsally, oval or obovate, glabrous. Dorsal and inter- 

 mediate ribs of carpel filiform and very much narrower than the 

 intervals, coming together at base and apex to form short promi- 

 nent ridges ; lateral ribs thick, broadly winged and contiguous 

 to those of the other carpel so as to form a broad one-edged 

 margin around the fruit, nerved dorsally at the inner margin and 

 also near the outer margin. Oil-tubes solitary in the intervals 

 or often two in the intervals nearest the lateral ribs ; two entirely 

 developed and two partially developed on the commissural side. 



* Almost certainly yellow. 



