634 UMBELLIFERiE. Trepocarpus. 



to the plains of the Platte ! and Texas ! P. Michigan, Dr. Wright ! May.— 

 Plant 2-3 feet high. Root somewhat fusiform. Stem rather stout, sulcate, 

 usually scabrous, leafy. Leaves mostly on long petioles ; the segments 

 pinnately incised or toothed ; those at the base of the peduncles often only 3- 

 cleft, with entire or sparingly toothed lobes. Rays of the umbel 12-20, 

 about an inch in length. Fruit nearly 3 lines long, entire at each end ; the 

 border tumid quite to the edge ; whence the area of the disk appears very 

 much depressed, especially in the dry state. Transverse section of the fruit 

 oblong-elliptical, exhibiting the seed closely invested with numerous vittse 

 and inclosed in the corky pericarp ; the vittffi and tubes of the border filled 

 with a terebinthine oil or turpentine. 



Tribe VII. CUMINE^. BC. 



Fruit contracted at the sides. Carpels with 5 primary filiform 

 ribs, of which the lateral ones are marginal ; and 4 more prominent 

 secondary ones ; all of them wingless. Seed straight, iiattish on 

 the face. Umbels compound. 



36. TREPOCARPUS. Nutt. in DC. mem. Umh. p. 56, t. 14. 



Caljrx-teeth subulate, at length deciduous. Petals obcordate, with an in- 

 flexed point. Fruit linear-oblong, pyramidal at the summit, S-angled: 

 primary ribs indistinct: secondary ribs 4, elevated, obtuse, with a single 

 vittffi beneath each. Commissure thick and spongy, grooved in the middle, 

 with 2 minute approximated vittse next the seed. Seed straight, convex on 

 the back. — A glabrous annual. Leaves many-parted; the segments of the 

 cauline one narrowly linear. Umbels opposite the leaves, of 3-5 rays. 

 Umbellets few-flowered. Involucre aud involucels of few filiform leaflets. 

 Flowers white. 



^t- T. jEiliusee (Nutt. ! 1. c.)— T. ^thusfB & brachycarpus, DC. I. c, S^ 

 'prodr. 4. p. 202. 



Prairies of Arkansas, Nuttall! Dr. Engiemann! Louisiana, Dr. Hale! 

 if Prof. Carpenter! June. — Plant about 2 feet high, "with a very strong 

 odor of Carrot," Dr. Engiemann. Stem striate, slender, branching. Leaves 

 very thin, tripinnately divided ; the rachis very narrow and winged : lower 

 ones with the segments broader, pinnatifid-toothed. Primordial leaves nar- 

 rowly linear. Umbels on peduncles longer than the leaves. Fruit 4-5 lines 

 long, thick and rigid; the primary ribs scarcely perceptible except in the dry 

 state. Vittae not visible externally. — T. brachycarpus, DC. only differs in 

 shorter fruit, and in the fewer rays of the umbel ; which are inconstant 

 characters. 



Tribe VIII. THAPSIEiE. Koch; DC. 



Fruit either dorsally compressed or nearly terete. Carpels with 

 5 filiform often bristly primary ribs ; of which the lateral ones are 

 placed on the face of the commissure : secondary ribs 4 ; the dorsal 

 ones filiform and the lateral ones winged ; or all of them winged 

 (hence the fruit is either 8-winged, or only 2.winged on each side). 



