156 UMBELLIFER^E. (PARSLEY FAMILY.) 



Var. aptcrmn. Fruit with strong and sharp ribs in place of wingr 

 (Smyrnium aureum, L. Zizia aurea, Koch.} With the winged form. 



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

 stem-leaves simply ternate or quinate, or 3-parted ; the divisions or leaflets ovate-lancer 

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

 sia trifoliata, L. Smyrnium cordatum, Wait. Thaspium atropurpureum, Nutt.) 

 From New York westward and southward. 



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

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



17. ZIZIA, DC. partly. (ZiziA T^NfDiA, Torr. & Gr.) 



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

 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. (Nam^d 

 for L B. Ziz, a Ehenish botanist.) 



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



18. BUPL.EtrRUM:, 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 $ot)y, an ox, and TrXevpoi/, a rib ; it is 

 uncertain why so called.) 



.1. 13. ROTUNDIF6LIUM, 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. IVISCOP LElTItA, 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 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 Sioxos, a disk, and TrAevpoi/, a rib.) 



1. JD. capillsicca, DC. Umbel few-rayed; leaflets of the involucre 

 3 - 5-cleft ; involucels longer than the umbellets ; fruit ovate in outline. 

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



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

 mostly ^jitire and shorter; fruit globular. Wet prairies, Kentucky and south- 

 ward. 



