UMBELLIFKR.'E. (PAUSLEY FAMILY.) 195 



lanceolate, ven/ sharply cut-senate, with a wcdgc-slmpcd entire base ; flowers deep 

 }cllow •,J'ruit obluiHj-omI , witli 10 wiii;^ed ridyes. — Moist river-biiiiks, &c. June. 



Viir. apterum. Fruit with stronjj^ and shaqj ribs in place of win^^s. 

 (Sni^'iniiiin iiurcmn, L. Zizia aiirea, Koch.) — With the winged form. 



4. T. trifoliatum. lluot-Uaves or some of tiicm round and heart-shaped; 

 stcm-lcares sim/ili/ termite or quinate, or 3-partcd; the divisions or leaflets ovate- 

 liiiiceolate or roundish, mostly abrupt or heart-shaped at the base, cnnuti I y toothed ; 

 flowers deep yellow ; Jruitj/lohusc-oroiil, with 10 winged ridges. — Kocky thickets, 

 Vermont to Wisconsin, and southward : rare eastward. June. 



Var. atropurpureum, Torr. & Gr. Petals deep dark-purple. (Thap- 

 sia trifoliata, />. ISniyrnium cordatum, Walt. Thaspium atropurpureum, 

 Nutt.) — From New York westward and southward. 



Var. ^ptei'Um. Petals yellow : fruit with sharp ribs in place of wings. 

 (Zizia conlata, Koch, Torr.) With the preceding form. 



17. ZIZIA, DC. partly. (Zizia § T.T.NfDiA, Torr. & Gr.) 



Calyx-teeth obsolete. Fruit ovoid-oblong, contracted at the junction of the 

 carpels so as to become twin, the cross-section of each seed nearly orbicular; 

 carpels somewhat fleshy when fresh, with .') slender ribs (which are more con- 

 sj)icuous when dry) : oil-tubes .'5 in each interval and 4 on the inner face. — A 

 perennial smooth and glaucous slender herb (2° -3° high), with 2 - 3-ternately 

 compound leaves, the leaflets with entire margins ; umbels with long and slen- 

 der rays, no involucre, and hardly any involucels. Flowers yellow. (Named 

 for /. B. Ziz, a Rhenish botanist.) 



1. Z. integeXTima, DC — Rocky hillsides : not rare. May, June. 



18. BUPLEURUM, Tourn. Tiiorougii-wa.x. 



Calyx-teeth obsolete. Fruit o\atc-ol)long, flattened laterally or .somewhat 

 twin, the carj)els .'i-ribbed, with or without oil-tubes. Plants with simple entire 

 Ie»ves and yellow flowers. (Name from ^ovs, an ox, and ivXtvpov, n rib.) 



I. B. u<)Tuxnii-bLii:.M, L. Leaves ovate, perfoliate ; involucre none; in- 

 volucels of .") ovate leaflets. — Fields, New York to Virginia: rare. (Adv. 

 from Eu.) 



19. DISCO PLEURA, DC. Mock Bishop-weed. 

 Calyx-teeth awl-shaped. Fruit ovoid ; the carpels each with 3 strong ribs on 

 the back, and 2 broad lateral ones united with a thickened corky margin : in- 

 tervals with single oil-tubes. — Smooth and slender branched annuals, with the 

 leaves finely dissected into bristle-form divisions, and white flowers. Involucre 

 and involucels conspicuous. (Name from bicrKm, n disk, and ■K\fvp6v, a rib.) 



1. D. capill^cea, DC. Unib.l few-rayed ; leaflets of the involucre .3 - 5- 

 cleft; involucels longer than the umbellcis ; fruit ovate in outline. — Rrackish 

 swamps, Massachusetts to Virginia, and -southward. Jul v- Oct. 



Var. ? costita, DC. Larger; rays and divisions of the involucre numer- 

 ous; ribs of the fruit stronger. — S. Illinois ( Fasw/) and sonthwe.stward. 



2. D. Nutt^IIii, DC. Uniiiel many-rayed ; leaflets of the involucre entire 

 and shorter ; fruit globular. — Wet prairies, Kentucky and southward. 



