COMPOSITAE (composite FAMILY) 



829 



9S6. X. canadense. 



1. X. spin6sum L. Hoary-pubescent, armed at the axils 

 with triple spines ; stems slender ; leaves lanceolate or ovate- 

 lanceolate, short-petiolate, white-downy 

 beneath, often 2-3-lobed or -cut ; fruit 

 about 1 cm. long, with a single short beak 

 or beakless. — Waste places, Me. to Ont., 



„„^ ^ . westw. and southw. (Nat. from Trop. 



985. X. spmosum. j^^ ^ ^^^ ^^^^ ^ ^^ 



2. X. canadense Mill. Leaves broadly ovate, cordate, 

 usually 3-lobed and simply or doubly dentate ; bnrs gla- 

 brous or merely granular- or glandular-puherulent ; the 

 body fusiform-ellipsoid, 14-17 mm. long, 5-8 nun. in 



diameter ; the beaks usually 2, straight 



or but slightly curved ; prickles scat- 

 tered, straight-tipped or hooked. (X. 



pensylvanicum Wallr. ? ; X. pungens 



Wallr. ; X. (/Z«&raii<7H Britton.) — Kich 



soil, especially in moist places. Fig. 



986. 



3. X. commune Britton. Similar in habit and foliage ; 

 beaks of the bur more or less strongly incurved, usually 

 hooked at the summit ; prickles numerous, crowded, 3-<3 mm. 

 long, hooked at the summit, hairy as is the feody. — Similar 

 situations. Fig. 987. 



4. X. speci5sum Kearney. 

 Of the same habit, foliage, 

 etc. ; bur ivith numerous 

 long (8-10 mm.) filiform 



usually stramineous and very hairy prickles; 



beaks moderately incurved and hooked. — Waste 



places and low moist ground, Tenn. to N. Dak. 



and Tex. ; also sparingly adventive on wool- 

 waste, etc., eastw. Fig. 988. 



5. X. infl^xum Mackenzie & Bush. Habit, 



foliage, etc., as in the three preceding species ; 



bur large, the body 2 cm. long, 0-7 mm. thick, 



ovoid-fusiform, merely granular-puberulent ; 

 beaks 2, very strongly 

 incurved^ often forming 

 a loop or arch over the 

 fruit ; prickles numerous 

 but less crowded than in 

 the preceding, firm in 

 texture, brownish, arcu- 

 ate, hooked at the summit, granular-puberulent, at leasi 

 toward the base. — Bottom lands, Courtney, Mo. (Bush). 



6. X. echinatum Murr. Of the same habit, etc.; burs 

 plumper ; the body thickish-ovoid, 15-22 mm. long, 8-12 

 mm. thick, for the most part densely pubescent as are also 

 the numerous short rigid hooked prickles and stout falcate- 

 incurved beaks. (X. canadense, var. Gray.) — Sea- 

 beaches, lake-shores, etc., Me. to N. C, and westw. chiefly 

 X. echinatuui. along the Great Lakes to N. Dak. and Sask. Fig. 989. 



HELI6pSIS Pers. Ox-eye 



Heads many-flowered; rays 10 or more, fertile. Involucral bracts in 2 or 5 

 rows, nearly equal ; the outer leaf-like and somewhat spreading, the inner shorter 

 than the disk. Receptacle conical ; chaff linear. Acheues smooth, thick, 4- 



