Xanthium. COMPOSTTiE. 377 



var. Canadense : fructiferous involucre pubescent-scabrous, or at length smooth ; the beaks 

 straight, or slightly incurved ; stem usually spotted. Torr. 6f Gr. I, c. X. macrocarpon, ^. 

 glabratum, DC. I. c. X. strumarium, Michx. fl. 2. p. 182. 



Stem 1-2 feet high, angular, roughish-pubescent. Leaves 3-6 inches long, broadly 

 cordate, more or less distinctly 3-lobed, the 3 principal nerves arising from the cuneate base 

 of the sinus : petioles 2-4 inches long. Heads in short axillary glomerate spikes. Mature 

 involucre or fruit nearly an inch long, clothed with short hooked prickles, and furnished at the 

 summit with 2 much shorter spinous beaks. 



Road-sides, barn-yards and waste places. A native of Europe ; introduced in many places : 

 the var. Canadense, in fields, in the western part of the State, and apparently indigenous. 

 August - September. 



2. Xanthium echinatum, Murray. Sea Cocklebur. 



Fructiferous involucre oval, very densely clothed with rigid slender prickles, which are 

 strongly hispid as well as the incurved beaks ; stem and petioles rough and spotted ; leaves 

 rough, broadly cordate, irregularly sinuate-toothed and obscurely lobed. — Murr. comm. Gostt. 

 6. p. 32. t. 4 ; Willd. sp. 4. p. 374 ; Pers. syn. 2. p. 558 ; Torr. ^ Gr.fl. N. Am. 2. p. 295. 

 X. maculatum, Raf. in Sill. jour. 1. p. 151. X. orientale, Muhl. cat. p. 89 ; Nutt. gen. 2. 

 p. 186, not of Linn. X. macrocarpon, Torr. compend. p. 353; Beck, hot. p. 210; DC. 

 prodr. 5. p. 523, in part. X. strumarium, Bigel. fl. Bost. p. 342. 



About the size of the preceding species, but stouter and somewhat succulent. Stem marked 

 with purple spots and stripes, strigosely pubescent. Leaves very rough, and finely sprinkled 

 with resinous particles on both sides. Mature fruit about an inch and a quarter long, and 

 much broader than in X. strumarium. The prickles are also more numerous, and, like the 

 strong and usually incurved beaks, hispid with bristly hairs. 



Sandy soils and borders of beaches, near salt or brackish water ; common on Long Island, 

 and on the banks of the Hudson as far north as Peekskill. August - October. De Candolle 

 confounded this species with his X. macrocarpum, which differs in its smaller and narrower 

 fruit, and in the much less numerous and stouter prickles. 



§ 2. AcANTHOXANTHiUM, DC. Fructiferous involucre with a single beak. — Leaves narrowed into 



a petiole, furnished with spines at the base. 



3. Xanthium spinosum, Linn. Thorny Cocklebur or Bur-weed. 



Spines 3-parted, slender; stem much branched; leaves entire or somewhat 3-lobed, 

 acuminate, sparingly strigose-pubescent above , the under surface and veins of the upper 

 canescent ; involucre cylindrical-oblong, with a short straight beak. — Linn. sp. {ed. 2.) 2. 

 p. 1400 ; Lam. ill. t. 655 ; Ell. sk. 2. p. 479 ; Torr. compend. p. 353 ; Beck, hot. p. 210 ; 

 Darlingt. fl. Cest. p. 478 ; DC. prodr. 5. p. 523 ; Torr. <^ Gr. fl. N. Am. 2. p. 295. 



Stem 2-3 feet high, strigosely pubescent. Leaves 2-3 inches long, ovate-lanceolate, 

 [Flora.] 48 



