KEY TO THE FAMILIES 3 



Fruit a nut or an achene. 33. Corylaceae 205 



Fruit a drupe or a samara. 101. Oleaceae oot) 



Fruit many-seeded; seeds each with a tuft of hairs. 



^ .30. Salicaceae 185 



II. Calyx present at least in the staminate or in the perfect flowers. 



1. Flowers, at least the staminate, in aments or ament-like spikes. 



Plant not parasitic; fruit a nut or an achene. , .^ ^ .^i, i. 



Staminate and pistillate flowers both in aments; frmt not with a bur 

 or CUD 

 staminate flowers 2 or 3 together in the axils of the bracts, each 

 with a calyx; pistillate flowers without a calyx. 



32. Betulaceae 202 



Staminate flowers solitary in the axUs of each bract, without a 

 calyx; pistillate flowers with a calyx. 



^ ' ^ 33. CORYL-ACEAE 205 



staminate flowers in aments; pistillate ones often solitary. 

 Fruit a nut, at least partly enclosed in a cup or bur. 



31. Fagaceae 199 



Fruit drupaceous, not enclosed in a cup or bur. 



(Garrya in) 95. Cornace.ie. 634 



Plant parasitic; fruit berry-Uke. 125. Loranthaceae 816 



2. Flowers, at least the staminate, not in aments. 

 a. Ovary superior. 



X Gynoecium of 1, or several and distinct carpels; stigma and style of 



k each solitary. 



Carpel soUtary. , . , ^. . , 



Ovary neither enclosed nor seated m a hypanthium or a calyx- 

 tube. . , , , , .. 

 Flowers not solitary in the axUs of the leaves; land plants. 

 Plants with scarious stipules; flowers cymose. 



43. CORRIGIOL.\CEAE. 267 



Plants not with scarious stipules; flowers clustered. 



36. Urticaceae 208 

 Flowers solitary in the axils of the leaves; aquatic plants. 



46. Ceratophyllaceae 284 

 Ovary enclosed in or seated in a hypanthium or a calyx-tube. 

 Stamens borne under the gynoecium; calyx corolla— like; 



herbs. 40. Nyctaginiaceae 255 



Stamens borne on the hypanthium or adnate to the calyx- 

 tube; calyx not corolla-like; shrubs. 

 Hypanthium becoming fleshy in fruit, enclosing the 

 taU-less achenes; calyx 4-merous; stamens 4 or 8; 

 leaves silvery-scurfy. 89. Euaeagnaceab 581 



Hypanthium not becoming fleshy; achenes tailed; 

 calyx 5-merous; leaves not scurfy. {Coleogyne and 

 Cercocarpus in) 60. Rosaceae 399 



Carpels several. 



Stamens inserted below the ovary. „^_ 



(Genera in) 48. Ranunculaceae 28o 



Stamens Inserted on the edge of a cup-shaped hypanthium. 



(Genera in) 60. Rosaceae 399 



Gynoecium of 2 or several united carpels; stigmas or styles 2 or several. 

 Ovary, by abortion, 1-celled and 1-ovuled. 

 Leaves with sheathing stipules (ocreae). 



37. POLYGONACEAE 210 



Leaves estipulate, or stipules, if present, not sheathing. 

 Trees or shrubs; ovary not seated in a hypanthium. 



34. Ulmaceae 206 

 Herbs or vines. 



Stipules herbaceous; inflorescence spicate or racemose; 

 leaf-blades palmately veined. 



35. Cannabinaceae 2Ci7 

 Stipules scarious, or hyaline, or none; inflorescence 



cymose: leaf-blades pinnately veined. 

 Fruit a utricle, or achene, circumscissile or bursting 

 irregularly. 

 Stipules wanting. 



Flowers subtended by an involucre formed 

 by more or less united bracts. 



37. POLYGONACEAE 210 



Flowers not involucrate. 

 Bracts not scarious. 



38. Chenopodiaceae 239 

 Bracts scarious. 39. Amaranthaceae 253 



Stipules present, scarious. 



43. Cobrigiolaceae 267 



