AKALYTICAL KEY. 27 



Ovary 1-celled; juice not milky. 



Style, if any, and stigma only one ; leaves simple ; 



no scarious bracts around the flowers. . Urticace^, 461 



Styles 3 ; embryo straight ; flowers involucrate. 



Eriogonum, in PoLYGOXACEiE, 436 

 Style or stigmas 2 or 3 ; embryo coiled or curved. 

 Stipules not scarious, leaves palmately cleft or 



palmately compound. . . Cannabineas, in Urticace^i:, 461 



Stipules scarious (or none) ; leaves opposite. Illecebrace^, 426 



Stipules none; but flowers with scarious bracts. Amarantace.e, 427 



Stipules and scarious bracts none . . Chenopodiace^, 430 



Shrubs or trees. 



Ovules a pair in each cell of the ovary. 



Fruit 2-celled, a double samara. Acerinea, in Sapixdace.e, 115 



Fruit a 1-celled and 1-seeded samara or a drupe. Oleaceje, 335 



Ovules single in each cell of the 



Three - nine-celled ovary ; leaves heath-like. . Empetrace.e, 487 

 Three-celled ovary ; leaves broad. . . . EHAMXACEiE, HI 



One - two-celled ovary ; styles or stigmas 2-cleft. Urticace^, 461 

 One-celled ovary ; style and stigma single and entire. 



Anthers opening longitudinally. . . Thyme l^ace^, 448 

 Anthers opening by uplifted valves. . . . Laurace.e, 446 



B» Flowers moncecious or dioecious, one or both sorts in catkins, 



1. OnI>/ one sort of flowers in catkins or catkin-like heads. 



Fertile flowers in a short catkin, head, or strobile. . . Urticace^, 461 



Fertile flowers single or clustered ; sterile in slender catkins (except in Fagus). 



Leaves pinnate ; fertile flowers and fruit naked. Juglandace.^5, 467 



Leaves simple ; fertile flowers 1-3 in an involucre or cup. Cupulifer.e, 470 



2. Both sterile and fertile flowers in catkins or catkin-like heads. 



Ovary and pod 2-celled, many -seeded. Liquidambar, in Hamamelide.^, 180 

 Ovary and pod 1-celled, many-seeded ; seeds furnished with 



a downy tuft at one end Salicace^, 480 



Ovary 1- 2-celled, only one ovule in each cell; fruit 1-seeded. 



Parasitic on trees ; fruit a berry. . . . Loramthace.e, 449 



Trees or shrubs, not parasitic. 



Calyx regular, in the fertile flower succulent in fruit. Urticace^, 461 

 Calyx none, or rudimentary and scale-like. 



Style and stigma one, simple ; the flowers in heads. Platanace^, 466 

 Styles or long stigmas 2. 



Fertile flowers 2 or 3 at each scale of the catkin. Cdpulifer^, 470 

 Fertile flowers single under each scale ; nutlets 



naked, waxy-coated or drupe-like. . . . Myricace^, 469 



Subclass IT. GYMNOSPERM^. Pistil an open scale or altered 

 leaf, bearing naked ovules on its margin or its upper surface, or in Taxus 

 entirely wanting. Flowers monoecious or dioecious. Conifers, 489 



