( M a 1 e fl o wers in globular heads in a terminal raceme. Females 

 jggj axillary, joined two together in a large prickly burr, with 



I incurved points XANTHIUM (p. 235). 



I Flowers, male and female, distinct, or in heads, not prickly . 134 

 jg 4 / Male perianth of 4 parts 135 



\Male perianth of 5 or 3 parts . . CHENOPODIACE^E (p. 370). 



( Leaves all radical, linear and fleshy, or transparent. Marsh 

 136-j or water plants 136 



(Stems leafy. Leaves flat .... URTICACEJE (p. 398). 



{Male flowers one or two on a stalk, with very long stamens. 

 Females sessile LITTORELLA (p. 367). 

 Male and female flowers minute, mixed together in a small 

 terminal head ERIOCAULON (p. 476). 



137 /Leaves opposite, simple .... MERCURIALIS (p. 395). 

 \Leavesalternate, pinnate . . . . POTERIUM (p. 141). 

 Leaves alternate, with sheathing stipules. Stamens 6. Nut 



enclosed in the calyx RUMEX (p. 379). 



Leaves small and fine, in tufts. Stamens 6. Fruit a berry 

 138J ASPARAGUS (p. 459). 



Leaves small and heath-like. Stamens 3. Fruit a berry 



EMPETRUM (p. 396). 

 Leaves radical, long, arrow-shaped. Stamens and carpels 



numerous. Aquatic plant . . . SAGITTARIA (p. 431). 

 f Flowers all male (a male specimen) . . " . . . .131 



\Flowers all female (a female specimen) 140 



Terianth 6-cleft, the 3 inner segments larger. Styles 3, with 

 short fringed stigmas. Leaves alternate or radical. 



t RUMEX (p. 379). 



Perianth 2- or 4-cleft. Stigma single, sessile, tufted. Leaves 



opposite, stinging . URTICA (p. 399). 

 Perianth 3-cleft. Styles 2," simple. Leaves opposite, not sting- 

 ing . . MERCURIALIS (p. 395). 



8. Trees or Shrubs. 



i 



Ul f Leaves opposite 142 



\ Leaves alternate or in tufts ....,. 145 

 Leaves divided, lobed or angular, deciduous . . . .143 

 Leaves entire, evergreen 144 



{Leaves lobed or angular. Stamens about 8. Fruit with two 

 diverging wings ACER (p. 96). 

 Leaves pinnate. Stamens in pairs, collected in-clusters. Fruit 

 with one erect wing .... FRAXINUS (p. 297). 

 Parasitical shrub with green dichotomous stems. Fruit a berry 



VISCUM (p. 204). 



Erect branching shrub with shining leaves. Fruit a few- 

 seeded capsule Buxus (p. 396). 



Male flowers in catkins, separated by scales only. Females 

 solitary or in clusters, or in catkins, usually different from 



the males * ... 146 



Flowers hermaphrodite or diclinous, each with a distinct 

 perianth 147 



144 



148 



