156 UMBELLIFEK^. (PAESLEY FAMILY.) 



Var. dpternm. Fruit with strong and sharp ribs in place of wings. 

 (Smymium aureum, L. Zizia aurea, Koch.) — With the winged foi-m. 



4. T. tnfoliatuin. Root-leaves or some of them round and heart-shaped; 

 stem-leaves simply ternate or quinate, or 3-parted ; the divisions or leaflets omte-lance- 

 olate or roundish, mostly abrupt or heart-shaped at the base, crenately toothed; 

 flowers deep yellow ; fruit, globose-ovoid, with 10 winged ridges. Rocky thickets, 

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



Var. atropurpttreum, Ton-. & Gr. Petals deep dark-purple. (Thap- 

 sia trifoliata, L. Smymium cordatnm, WaU. Thaspium atropurpm-eum, Nutt.) 

 — From New York westward and southward. 



Var. dpterum. Petals yellow : fruit with sharp ribs in place of wings. 

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



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



Calyx-teeth obsolete. Frait 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 5 slender ribs (which are more con- 

 spicuous when dry) : oil-tubes 3 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. 2Rz, a Bhenish botanist.) 



1. Z. integcrrima, DC. — Rocky hill-sides ; not rare. May, June. 



18. BUPIiEtJRTJM, Tomn. Thobough-wax. 



Calyx-teeth obsolete. Frait ovate-oblong, flattened laterally or somewhat 

 twin, the carpels 5-ribbed, with or without oil-tubes. Plants with simple entire 

 leaves and yellow flowers. (Name from 0oCr, an ox, and ivKtvpov, a rib ; it is 

 uncertain why so called.) 



I. B. KOTUNDirdLiUM, L. Leaves broadly ovate, perfoliate; involucre 

 none ; involucels of 5 large ovate leaflets. — Fields, New York, Penn., and Vir- 

 ginia; rare. (Adv. from Eu.) 



19. DISCOPliEVBA, DC. Mock Bishop-wkkd. 



Calyx-teeth awl-shaped. Fruit ovoid ; the cai-pels each -vvith 3 strong ribs on 

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

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

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

 and involucels conspicuous. (Name from SiWor, a disk, and Trkcvpov, a rib.) 



1. D. capillacca, DC. Umbel few-rayed; leaflets of the involncro 

 3 - 5-cleft ; involucels longer than the umbcUots ; frait ovate in outline. — 

 Brackish swamps, Massachusetts to Virginia, and southward. July - Oct. 



2. D. Nuttilllii, DC. Umbel many-rayed ; leaflets of the involucre 

 mostly entire and shorter ; frait globular. — Wet prairies, Kentucky and south- 

 ward. 



