PL ex . mon. 
9. URTICEiE. 21. Xanthium. 255 
celled; perigonium 0; ovary 1 ; styles 2, persistent; utri « 
ca/ws 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 ; male flowers above, female below. 
Xanthium inerme . Unarmed ditch-burr » 
Stem not armed ; leaves heartshape, 3-ribbed at bottom* 
Xanthium, seu Lappa minor, Ran Syn. 140 ; Park , 1222. 
Bardana 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, ser* 
rated ; flowers green. 
Fam. X. 10. EUPHORBIACEiE. 
Flowers unisexual ; perigonium simple, free, 3 or 4-cut» 
sometimes 0. — Male. Stamens a 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 3, 2-cut or lobed ; regma 2 or 3-coccous ; 
cocci 1 or 2-seeded ; placentarium apicillate ; seed appended ; 
corcu r um straight, flat ; radicle laterally adverse ; peris perm 
fleshy, involute. — Stem herbaceous or frutescent ; juice 
often milklike, very acrid ; flowers either solitary, spiked, 
©r girt with an involucrum. 
A. Monoicous ; flowers in an involucrum ; stamen 1. 
Bractece many ; bracteolce 2 ; 
mter lobe of the involucrum ovate, not cut 
Galaehceus. 22. 
Bractece many ; bracteolce 2 ; 
mter lobe of the involucrum lunate, 2-horned Esula. 23. 
Bractece many ; bracteolce connate ; 
'mter lobe of the involucrum lunate, 2-horned 
Characias. g'E 
Bractece and bracteolce 0 ; 
mter lobe of the involucrum ovate, not cut 
ChamMcyck. c Z$s 
