320 DIPSACE^. DiPSAcus. 



Order LIV. DIPSACE^E. Vaill; DC. The Scabious Tribe. 



Tube of the calyx adherent to the ovary, or sometmies free except at the summit; 

 the Hmb various, sometimes forming a bristly or plumose pappus. Corolla 

 tubular ; the limb 4 or 5-lobed, somewhat irregular. Stamens 4, distinct or 

 rarely united in pairs, often unequal. Ovary one-celled, with a single suspended 

 ovule. Fruit an achenium or membranaceous, not opening, crowned with the 

 limb of the calyx, 1-celled, 1-seeded. Embryo nearly the length of the fleshy 

 albuiren. — Herbs with opposite or whorled sessile leaves, destitute of stipules. 

 Flowers aggregated on a common receptacle, in dense involucrate heads, each 

 surrounded at the base with a very short involucel. 



1. DIPSACUS. Toiirn.; Linn. : E?idl. gen. 2191. teasel. 



I From the Greek, dipsao, to be thirsty ; the upper leaves holding water at their connate bases] 



Flowers capitate ; the involucre many-leaved, longer than the somewhat foliaceous and 

 acuminate chaff of ihe receptacle. Involucels 4-sided, closely investing the ovary and 

 fruit. Tube of the calyx coherent with the ovary ; the limb cup-shaped or discoid. Limb 

 of the corolla 4-cIeft. Stigma longitudinal. — Biennial erect stout herbs, hairy or prickly. 

 Leaves opposite, often connate at the base, undivided or laciniate. Heads large, oblong or 

 roundish ; the expansion of the flowers commencing about the middle, and proceeding in 

 opposite directions. Corolla pale purple, yellowish or whitish. 



1. DiPSACus sYLVESTEis, Mill. Wild Teasel. 



Leaves sessile, slightly connate , radical ones crenate-toothed ; scales of the receptacle 

 straight at the extremity ; involucres curved upward. — Mill. diet. no. 2 ; Engl. hot. t. 1032 ; 

 Pursh,Jl. \.p. 96 ; Torr.Jl. 1. p. 164 ; DC. prodr. 4. p. 645 ; Beck, hot. p. 165 ; Darlingt. 

 fl. Cest. p. 98 ; Torr. 4- Gr. Jl. N. Am. 2. p. 54. 



Stem 3 — 5 feet high, branching, angular and (as well as the involucres and midrib of the 

 leaves) prickly. Radical leaves lanceolate-oblong ; cauline ones lanceolate, serrate or entire. 

 Leaflets of the involucre slender, longer than the head. Heads of flowers oblong-ovoid. 

 Corolla pale purple or almost white, pubescent. Scales of the receptacle oblong-cuneate, 

 tapering into a long straight point ; those at the top of the head longest. 



Fields, road-sides, etc. ; naturalized in many places. A native of Europe. Fl. July — 

 August. This is suspected by some botanists to be the original of the D. Fullonum, or 

 Fuller''s Teasel. 



