336 OKDER LXL UMB*:LLIFER.ffi. 



ilar, but smaller. Flowers sessile ; filaments red near the summit 

 Seeds compressed. — White. $ . Aug. — Sept. Middle Geo. 3 — 6 feet. 



Genus XVIII. — ARCHE'MORA. D. C. 5—2. 

 (From Archemous, son of Lycurgus.) 



Limb of the calyx 5-toothed. Petals obcorclatc, with an in- 

 flexed point. Fruit somewhat elliptic, lenticularly compressed. 

 Carpels ribbed ; lateral ones dilated. Involucre wanting or 

 few-leaved ; involucels many-leaved. Perennial, aquatic herbs. 



1. A. rig'ida, (D. C.) Stem erect, rigid, terete, striate, fistulous. 

 Leaves pinnately divided ; segments ovate, oblong, remotely toothed or 

 entire, with a cartilaginous margin. Umbel of many slender rays. 

 Fruit with the dorsal ribs greenish ; lateral ones with a membranace- 

 ous margin. — White. If. Sept. Georgia — Florida. 3 — 5 feet. 



2. A. teuna'ta, (Nutt.) Stem striate, slender. Leaves ternately di- 

 vided, on long petioles ; segments linear, acute, entire, alternate. Invo- 

 lucre nearly wanting ; involucel 5 — 6-leaved. Fruit oblong, elliptic, 

 surrounded with a thick, winged margin. — White. 71. Middle Car. 

 and Geo. 2 — 3 feet. 



Genus XIX.— PASTINA'CA. Touru. 5—2. 

 (From pastinum, a forked tool, which the roots resemble.) 



Calyx teeth obsolete or minute. Petals nearly orbicular, en- 

 tire. Fruit much compressed, with a flat margin. 



1. P. sati'va, (L.) Stem glabrous. Root fusiform. Leaves pinnate; 

 leaflets glabrous, ovate-oblong, obtuse, unequally toothed and serrate, 

 incised at the base, terminal one 3-lobed. — bellow. Europe. Parsnep. 



Genus XX.— POLYT^E'NIA. D. 0. 5—2. 

 (From tho Greek polus, many, and tainia, vitta.) 



Calyx 5-toothed. Petals oblong, with the apex emarginate, 

 indexed. Fruit oval, glabrous, compressed on the back, with a 

 broad margin. 



1. P. Nuttai/lia, (D. C.) Stem glabrous, sulcate, leafy. Leaves on 

 long petioles, bipinnate ; segments incised or toothed; upper ones only 

 3-cleft. Rays of the umbel 12— 20.— Yelldw. Lou. 2— 3 feet. 



Tribe VIL— CUMINE'JE. 



Fruit contracted at the sides. Carpels with 5 primary ribs 

 and 4 secondary ones. Umbels compound. 



Genus XXI.— TREPOOAR'PITS. Nutt. 5— 2. 

 (From tho Greek trepo, to turn, and karpos, fruit) 



Calyx 5-toothed ; teeth subulate. Pi tals obcordate. Fruit 

 linear-oblong, 8-anglod, straight. 



