TiiASPiuM. UMBELLIFERiE. (ila 



in the dried state. — The fruit of this s])eeies, as well as its general appear- 

 ance, diflers so much from the preceding that it should probably be Bcim- 

 rated as a distinct genus. 



Tribe IV. SESELINE/E. Koch ; DC. 



Transverse section of the fruit orhieuhir or n(>arly so. Carpcia 

 •with 5 filiform or winged ribs, of which the lateral ones arc mar- 

 ginal, and either equal with or a little broader than tiic others. 

 Intervals with one or more vittie, very rarely without any. Scrd 

 somewhat teretely convex on the back, llattish on the face. — Umbels 

 perfectly compound. 



17. THASPIUM. Null. gen. 1. 'p. 19G ; DC. i^rodr. 4. p. 153. 



Calyx-teeth lanceolate, or nearly obsolete. Petals elliptical, attenuated 

 into a long jnflexed point. Styles slender, as lono; as the ovary, somewhat 

 diverging. Fruit not contracted at the sides, elliptical. Carpels convex, 

 with 5 winged mostly equal ribs. Intervals striate, with single vitts. Com- 

 missure with 2 vittas. Seed somewhat. terete. — Perennial herbs. Leaves 

 ternately or biternately divided ; the radical ones sometimes undivided. 

 Umbels terminal and opposite the leaves, without an involucre. Involucels 

 .3-leaved, lateral. Flowers yellow or purple. 



These plants accord in habit with Zizia (Z. aurea), from which Thaspium 

 aureum is only to be distinguished by the fruit. Should the character of tlio genus 

 be extended so as to include Zizia aurca, the latter name (Koch's cliaracter being 

 changed), miglit be retained for Z. (Ttenidia) integerrima, which on this account 

 we have still left in connexion with Zizia. 



1. T. cordatum: radical leaves usually simple, cordate, crenalely toothed; 

 cauline ones ternately divided ; the segments ovate or ovate-oblong, serrate ; 

 winged ribs of the carpels ecjual. 



a. flowers yellow. — Smyrnium cordatum, Walt. Car. p. 114: Michx.f 

 Jl. 1. p. 170 ,• EU. sic. 1. p. 359 ; Torr. ! Jl. 1. p. 307. S. trifoliatum, Null, 

 gen. 1. p. 195, excl. syn. Linn. Zizia cordata, Koch, Umb. p. Ii29, ex DC. 

 prodr. 4.7>. 100; Hook. Jl. Bor.-Am. l.p. 260 ; Darlingt. Jl. Cest. p. 18G; 

 Hook. Sf Am. hot. Beechcy, siippl. p. 347. 



I3. flowers dark purple.— Thapsia trifoliala, Linn..' spec. 1. p. 262.- Smyr- 

 nium atropurpureum, Lam. diet. 3. p. G67 ; Pursh.Jl. 1. p. 196. Thas[)ium 

 atropurpureum, Nutt. ! gen. 1. p. 196; DC. prodr.^ 4. p. 154. Cnidium 

 atropurpureum, Spreng. in Schull. syst. 6. p. 418 ; Torr.! Jl. 1. p. 307. 



Woods, particularly along the banks of rivers, and in fields, Canada ! 

 and Saskatchawan, to Florida ! and Louisiana ! Oregon, Mr. Tolmir. /?. 

 New Jersey ! and Pennsylvania ! May-Jiuic.— Plant 1-2 feet hi-h, usually 

 glabrous, but sometimes minutely puljesceut- Radical kcivcs 1-4 inches in 

 diameter, sometimes lobed or 2-:3-parted, on long petioles; tlie lower cauline 

 ones on petioles 1-2 inches long; the uppermost ones nearly sessile : segments 

 1-3 inches long. Umbels with 9-12 rays, which are thick anil scarcely 

 more than an inch in length. Umbellets crowded. Involucels of 1-3 minute 

 leaflets. Flowers in /?. at tirst greenish, but at length dark purple. Fruit 

 broadly ovate, dark purple with pale marginal ribs; tiit conuni-vsurc broad. 



