lxiv 
INTRODUCTION. 
Trees: flowers in separate heads. 
Liquidambar. Styles 2. Pods 2-beaked, 2-celled, several-seeded. 432 
Platanus. Style 1. Nutlets club-shaped ; 1-celled, l-seeded. 433 
* * Staminate flowers in catkins : calyx none or scale-like. 
-♦-Fertile flowers in catkins or spikes. Leaves simple. 
Betulacee. Fruits scale-like or nut-like, 2 -3 under each bract. 451 
Comptonia. Nutlets 1 under each bract of the burr-like catkin. 420 
Carpinus. Nutlets single in the axil of a leaf-like bract. 419 
Ostrya. Nutlets each in a bladdery bag, making a Hop-like catkin. 419 
Fertile flowers 2 together, naked, forming fleshy»or dry drupes. 
Ju glandacee. Seed large, crumpled and lobed. Leaves pinnate. 410 
# # * Staminate and fertile flowers both in glumes, naked. 
Zizania. Flowers panicled. Stamens 6. 573 
* * * * Staminate fl. with a regular calyx (or involucre) and no corolla. 
-♦-Nuts 1-celled, large, 1-3 together in an involucre or cup. 
Cupulifere. Staminate flowers mostly in aments. Trees. 412 
-♦—♦-Fruit an achenium or utricle: styles only 1 or 2. 
Stamens 5 or fewer. 
Urticacee. Calyx fleshy or herbaceous. Embryo in albumen. 433 
Chenopodiacee. Calyx herbaceous or fleshy. Embryo coiled. 57b 
Amaranthacee. Calyx dry and scarious. Embryo coiled around 
albumen. J 382 
++ ++ Stamens 12-24. 
Ceratophyllum. Calyx herbaceous. Achenium horned. 401 
H- "'“' 4 “Fruit 3-celled or an achenium : styles or stigmas 3 or more. 
Egphorbiacee. Pod 3-lobed, 3-cell^d, 3-coccous. ** 
***** Flowers furnished with both calyx and corolla. 
-♦-Head imbricated with scarious bracts. Stamens 4. 
Eriocaulon. Sepals and petals free. Pod 2-celled, 2-seeded. Stig.2. 514 
-♦—•-Flowers spiked. Stamens 4 or 8. 
Myriophyllum. Sepals and petals adherent to the 4-celled nutlet. 1 
-^-Flowers scattered on a scape. Stamens numerous. 
Sagittaria. Sepals and petals 3, free. Achenia wing-margined, 
collected in a head. & 4WJ 
Order Monatlelpliia. Stamens united by their filaments. 
* Pod 3-lobed, 3-celled, 3-seeded. Flowers with a regular calyx* 
Phyllanthus. Stamens 3, much united. Stigmas 6. fl 
Acalypha. Stamens 8 - 16, united at the base. Styles cut-fringed. 4u 
* * Flowers naked, in the axils of scales, forming catkins. 
Conifere. Fruit a cone or strobile. 108 
Order Syngenesia. Stamens connected by their anthers. 
* Fruit an achenium. 
Xanthium. Staminate and fertile flowers in separate involucres, the 
latter a 2-celled burr. F 221 
Ambrosi a. Staminate and fertile flowers in separate involucres, the 
latter nut-like, 1-celled. r 
Iva. Stam. and fertile flowers in the same open cup-like involucre- 
* * Fruit a fleshy pod. 
Cucurbitacee. Anthers elongated and tortuous. Calyx and corolls 
epigynous. 
