30 KEY, BASED UPON FLOWERS. 



A KEY, BASED MAINLY DPON THE FLOWERS, 



Designed as an Aid in the Identification of the Species represented in Part I. 



a. Angiospermae seeds in a closed ovary. 

 b. Polypetalous petals present and distinct. 



C. Stamens numerous, more than 10, and calyx inferior wholly free from the 



pistil or pistils. 

 d. Pistils numerous and cohering in a cone-like mass. (Mognoliacice.} 



. Anthers opening inward; leaves folded lengthwise in the bud (Magnolia), 

 pointed at both ends, oval, thin and green above and below. 



1. M. ACUMINATA. 



ee. Anthers opening outward and leaves folded crosswise in the bud. 



2. LlRIODENDRON TULIPIFERA. 



dd. Pistil solitary but compound, as shown by styles and ovary-cells; calyx 

 valvate in the bud, deciduous (Tiliacece); stamens somewhat 

 polydelphous (Tilia), and with 5 petal -like scales opposite the 



petals 3. T. AMERICANA. 



CC. Stamens few, not more than 10, alternate with the petals when of the same 



number. 



d. Calyx inferior free from the ovary. 



e. Ovaries 2-5, separate; stamens distinct and inserted on the receptacle; 

 trees with piunately compound and uniformly opaque leaves. 



4. AlLANTHUS GLANDULOSUS. 



ee. Ovary single, but compound as shown by the cells, styles or stigmas. 

 /. One-celled and one-seeded; styles or stigmas three; shrubs or trees 

 with regular flowers (Anacardiacece); leaves compound with 11- 

 31 oblong lanceolate acuminate leaflets; common petiole densely 

 villous and not winged; flowers in terminal thyrses. 



5. RHUS TYPHINA. 



ff. Three-celled with two ovules in each; style single; flowers irregular; 

 stamens 6-8 (Aescidus); fruit covered with prickles, leaves pal- 

 mately compound with 7 obovate leaflets. .6. A. HIPPOCASTANUM. 

 dd. Calyx superior adnate to the ovary; flowers arranged in umbels; 

 stamens 5; styles 5; fruit drupe-like with 5 cells each with a 

 single ovule (Aralia); arborescent and armed with prickles. 



8. A. SPINOSA. 



bb. Apetalous without petals. 

 c. Flowers not in catkins; pistil one, simple or compound, and the cells of ovary 



containing 1-2 seeds each. 



d. Ovary inferior adnate its whole length to the calyx -tube 1-celled and 

 1-seeded; style 1 stigmatic down the side (Nyssa); fertile pedun- 

 cles bearing each two or more flowers 9. N. MULTIFLORA. 



dd. Ovary superior, free from the calyx. 



e. Stipules sheathing the stem; trees with naked monoecious flowers 



arranged in heads 13. PLATANUS OCCIDENTALS. 



ee. Stipules not sheathing the stem, or none. 

 /'. Ovules, a pair in each cell of the ovary, which becomes in 



g. Fruit, a double samara; leaves simple and palmately-veined (Acer); 

 flowers appearing with the leaves in pendulous corymbs. 



7. A. SACCHARINUM. 



gg. Fruit, a 1-celled and 1-seeded samara (Fmxinus); flowers dioecious; 

 calyx persistent at the terete base of the samara, 



10. F. AMERICANA. 

 ff. Ovules single in each of the one or two cells of the ovary; stigmas two 



(Ulmacew). 



g. Fruit, a 1 celled samara winged all round (Ulmus), which is without 

 a ciliate fringe, and nearly or quite sessile; leaves rough above, 



