156 UMBELLIFEUjE. (parsley family.) 



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

 (SmjTnium aurcum, L. Zizia aurea, Koch.) — Witli the winged form. 



4. T. tl'ifbliatUIll. Root-leaves or some of them round and heart-shaped; 

 stan-leaves simply temate or quinate, or 3-parted ; the divisions or leaflets ova.'e-lance- 

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

 flowers deep yellow ; fruit globose-ovoid, with 1 3 winged ridges. Rocky thickets, 

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



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

 sia trifoliata, L. Smyrninm cordatum, Walt. Thaspium atropurpureum, Nutt.) 

 — From New York westward and southward. 



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

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



17. ZIZIA, DC. partly. (Zizia $ T.eni'dia, 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 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. Ziz, a Rhenish botanist.) 



1. 25. illtegerrima, DC. — Rocky hill-sides ; not rare. May, June. 



18. BUPLEtRUM, Tourn. Thorough-wax. 



Calyx-teeth obsolete. Fruit 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 (3oi>s, an or, and TrXtvpov, a rib ; it is 

 uncertain why so called. ) 



1. B. eotundii-olium, 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. B>ISC©PI,EIJRA, 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 : inter- 

 vals with simrle ^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 8io-kos, a disk, and n\evpov, a n'&.) 



1. D. capillacea., DC. Umbel few-rayed; leaflets of the involucre 

 S-5-cleft; involucels longer than the umbellets ; fruit ovate in outline. — 

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



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

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

 ward. 



