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^eagnace.e, 424 

 Herbs : with the calyx colored like a corolla. 



Leaves opposite, simple. ' Nyctagixace.*:, 404 



Leaves alternate, pinnate Poterium, in Rosacea, 146 



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

 Stipules (ochrea;) sheathing the stem at the nodes. 



Tree : the calyx none : flowers monoecious, in heads. Platanace.e, 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^e, 427 

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

 Not aquatics, herbs. 



Ovary 10-celled : berry 10-seeded. . . . Phytolaccace^:, 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, 440 

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

 Stipules not scarious ; leaves palmately cleft or 



palmately compound. . Cannabineaj, in Urticace.e, 440 



Stipules scarious. . . Illeccbreas, in Caryophyllaceje, 87 

 Stipules and scarious bracts none : stamens inserted high up 



on the tube of the calyx. Scleranthus, in Caryophyllaceje, 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. Acerinese, in Sapindace^e, 116 



Fruit a 1 -celled and 1 -seeded samara or a drupe. Oleace^:, 400 



Ovules single in each cell of the 



Three - nine-celled ovary : leaves heath-like. . EMPETRACEiE, 440 

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

 One -two-celled ovary: styles or stigmas 2-clcft. Urticace.e, 440 

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

 Anthers opening longitudinally . . . Thymeleace^e, 424 

 Anthers opening by uplifted valves. . . . Laurace.e, 422 



B. 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. . . Urticace^e, 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 



