ANALYTICAL KEY. 29 



Ovary really free from the calyx, but permanently invested by its 

 tube, or the base of it, so as to seem inferior. 

 Shrubs, with scurfy leaves : flowers mostly dioecious. El^agnace^e, 424 

 Herbs : with the calyx colored like a corolla. 

 Leaves opposite, simple. ..... Nyctaginace^e, 404 



Leaves alternate, pinnate Poterium, in Rosacea, 146 



Ovary plainly free from the calyx, which is sometimes wanting. 

 Stipules (ochreas) sheathing the stem at the nodes. 



Tree : the calyx none : flowers monoecious, in heads. Platanaceje, 446 

 Herbs : the calyx present and commonly petal-like. Polygonace^e, 414 

 Stipules not sheathing the stem, or none. 

 Aquatic herbs, submersed or nearly so. 



Leaves whorled and dissected : style single. Ceratophyllace^:, 427 

 Leaves opposite, entire : styles 2 : ovary 4-celled. Callitrichace^;, 427 

 Not aquatics, herbs. 



Ovary 10-celled : berry 10-seeded. . . . Phytolaccace^e, 405 

 Ovary 3- (rarely 1 - 2-) celled : juice usually milky. Euphorbiace^e, 430 

 Ovary one-celled : juice not milky. 



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



no scarious bracts around the flowers. . . Urticace^e, 44C 

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

 Stipules not scarious ; leaves palmately cleft or 



palmately compound. . Cannabineae, in Urticace^, 44C 



Stipules scarious. . . Illecebreae, in Caryophyllace^e, 87 



Stipules and scarious bracts none : stamens inserted high up 



on the tube of the caiyx. Scleranthus, in Caryophyllace^:, 87 

 Stipules none : but flowers with scarious bracts. Amarantaceje, 411 

 Stipules and scarious bracts none . . Chenopodiace;e, 405 

 Shrubs or trees. 

 Ovules a pair in each cell of the ovary. 



Fruit 2-celled, a double samara. Acerineag, in Sapindaceje, llti 



Fruit a 1-celled and 1 -seeded samara or a drupe. Oleace^e, 4CKi 



Ovules single in each cell of the 



Three - nine-celled ovary : leaves heath-like. . Empetrace^e, 446 

 Three-celled ovary : leaves broad. . . . Rhamnace^e, 113 



One - two-celled ovary : styles or stigmas 2-cleft. Urticace^, 440 

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

 Anthers opening longitudinally . . . ThymEleace^, 424 

 Anthers opening by uplifted valves. . . . Laura ce^:, 422 



15. Flowers (monoecious or dioecious) one or both sorts in catkins. 



1. Only one sort of flowers in catkins or catkin-like heads. 



Fertile flowers in a short catkin, head, or strobile. . . Urticaceje, 440 

 Fertile flowers single or clustered : sterile ones in slender catkins. 



Leaves pinnate : fertile flowers and fruit naked. . Juglandaceje, 447 



Leaves simple ; fertile flowers 1-3 in an involucre or cup. Cupuliferje, 449 



