Pl.ex.mon. 9. URTICE^. 21. Xanthium. 255 



celled; perigonium 0; ovary 1; styles 2, perbistent; utri" 

 cuius membranaceous, enclosed in the hardened involu- 

 crum ; seed erect, corculum straight ; cotyledon ovate ; radicle 

 below. — Herb hamous; leaves petiolate, alternate, rather 

 rough, palmately ribbed ; flowers spiked, axillary or termi- 

 nal ; spike short ; maie flowers above, female below. 



Xanthium inerme. Unarmed dilch-hurr. 



Stem not armed ; leaves heartshape, S-ribbed at bottom. 



Xanthium, sen Lappa minor, Rail Syn, 140 ; Park. 1332. 

 Bardaha minor, Ger. em. 809, 2. 

 Xanthium Strumaria, Lin. S. P. 1400. 

 Louse burr. Ditch burr^ Lesser burr-dock. 



Deep rich soil ; annual ; August and September. 

 Root fibrous ; stem much branched ; leaves lobed, sei*- 

 vated ; fl,owers green. 



Fam. X. 10. EUPHORBIACEiE. 



Flowers unisexual ; perigoniun simple, free, 3 or 4-Cut, 

 sometimes 0. — Malk. Stamens x to 12; filaments often 

 jointed in the middle, inserted on the receptacle ; anthers 

 double. — Fem. Ovary free, often stipitate ; styles 2 or 3 ; 

 stigmata 2 or ?>, 2-cut or lobed ; regma 2 or 3-coccous ; 

 cocci 1 or 2-seeded; placentarium apicillate; seed appended; 

 core?., 7/m straight, flat ; radicle laterally adverse; perisperm 

 fleshy, involute. — Stem herbaceous or frutescent ; juice 

 often milklike, very acrid ; flowers either solitary, spiked, 

 or girt with an involucrum. 



A. Monoicous ; flowers in an involucrum j stamen I. 



Bractece many ; bracteolce 2 ^ 

 otiter lobe of the involucrum ovate, not cut 



Galarhceus. 22. 

 BractecB many ; bracteolce 2 ; 

 outer lobe of the involucrum lunate, 2-horned Esula. 23. 



Bractece many ; bracteolce connate ; 

 outer lobe of the involucrum lunate, 2-horned 



Characias. 24-. 

 Bractece and bracteolce Q ; 

 outer lobe of the involucrum ovate, not cut 



ChaMx1;cyce. 2f, 



