Ixxii INTRODUCTION. 



( Male flowers in globular heads in a terminal raceme. Females 

 ^ggj axillary, joined two together in a large prickly burr, with 



| incurved points XANTHIUM (p. 235). 



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



j 04 /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 



185-1 or water plants 136 



Stems leafy. Leaves flat .... URTICACE^J (p. 398). 

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



og r Females sessile LITTORELLA (p. 367). 



Male and female flowers minute, mixed together in a small 



terminal head ERIOCAULON (p. 476). 



-ow /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 

 138 i 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. 481). 



r Flowers all male (a male specimen^ 131 



L Flowers all female (a female specimen) 140 



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

 short fringed stigmas. Leaves alternate or radical. 



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. 



-.- /Leaves opposite 142 



141 \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 

 144 I VISCUM (p. 204). 

 I Erect branching shrub with shining leaves. Fruit a few- 



V. seeded capsule Buxus (p. 396). 



'Male flowers in catkins, separated by scales only. Females 

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

 145-1 the males . . 146 



139 



140 



Flowers hermaphrodite or diclinous, each with a 'distinct 

 perianth 147 



