KEY TO THE FAMILIES 3 



Fruit a nut or an achene. 33. Corylaceae 205 



Fruit a drupe or a samara. 101. Ole.aceae 655 



Fruit many-seeded; seeds eacb 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. 



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

 or cup. 

 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 axils of each bract, without a 



calyx; pistillate flowers with a calyx. 



33. Coryl-aceae 205 

 Staminate flowers in aments; pistUlate ones often solitary. 



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



31. Fag.\ce.\e 199 

 Fruit drupaceous, not enclosed in a cup or bur. 



{Garrya in) 95. CORNACEAE. 634 



Plant parasitic; fruit borry-like. 125. Loranthaceae 816 



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



a. Ovary superior. 



Gynoecium of 1, or several and distinct carpels; stigrma and style of 

 each solitary. 



Carpel soUtary. 



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

 tube. 

 Flowers not solitary in the a.xils 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 soUtary in the a.xils of the leaves; aquatic plants. 



46. CERATOPHYLL-ACEAE 284 

 Ovary enclosed in or seated in a hypanthiiuii or a caly.x-tube. 

 Stamens borne under the gynoecium; calyx coroila~like ; 



herbs. 40. Nyctaginiaceae 255 



Stamens borne on the hypanthium or adnate to the calyx- 

 tube; calyx not coroUa-Uke; shrubs. 

 Hj-panthium becoming fleshy in fruit, enclosing the 

 tail-less achenes; calyx 4-nierous; stamens 4 or 8; 

 leaves silvery-scurfy. 89. ELlAEAGNACEAE 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 285 



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



(Genera in) 60. Rosaceae 399 



Gynoecium of 2 or several united carpels; stig-mas 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 207 

 Stipules scarious, or hyaline, or none: inflorescence 



cymose: leaf-blades pinnately veined. 

 Fruit a utricle, or achene, circximscissile 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. CHENOPODIACE.AE 239 



Bracts scarious. 39. Amaranthaceae 253 



Stipules present, scarious. 



43. COBRIGIOLACE-AE 267 



