KEY, BASED UPON FLOWERS. . 3 



</ 2 . Dioecious ; stamens 10 ; tree unarmed. 



27. GYMNOCLADUS CANADENSIS. 



f/ 3 . Polygamous ; stamens 5 ; tree armed with thorns usually triple 

 (Gleditschia) pods 



Linear, many-seeded 28. GLEDITSCHIA TRIACANTHOS. 



Obliquely ovate, 1-seeded 109. GLEDITSCHIA MONOSPERMA. 



f 3 . Regular, stamens 



Ten ; petals distinct (Prosopis) 129. P. JULIFLORA. 



Indefinitely numerous; petals united below (Acacia) 



155. A. MELANOXYLON. 



d 2 . Calyx superior adnate to the ovary ; flowers in umbels ; stamens 5 ; 

 styles 5; fruit drupe-like with 5 cells each with a single ovule (Aralia); 

 arborescent and armed with prickles 8. ARALIA SPINOSA. 



2 . Gamopetalous petals present and united ; stamens 

 c. As many as the lobes of the corolla which is 



d. Irregular ; ovary 2-celled (Bignoniacece) ; leaves simple and 



Broadly-ovate (Catalpa) 89. C. BIGNONIOIDES. 



Linear (Chilopsis) 134. C. SALIGNA. 



d*. Regular ; stamens 



Two 112. OSMANTHUS AMERICANA. 



Five (Caprifoliacece) leaves pinnate (Sambucus) and glaucous 



157. S. GLAUCA. 

 c 2 . Fewer than the lobes of the corolla, inserted on its base and filaments 



distinct 61. DIOSPYROS VIRGINIANA. 



c 3 . More numerous than the lobes of the 5-toothed corolla, distinct and free 



from it (Ericaceae) ; fruit 

 d. Fleshy and ovary 



5-celied, several ovules in each cell 132. ARBUTUS MENZIESII. 



5-10-celled, single ovule in each cell. .133. ARCTOSTAPHYLOS PUNGENS. 

 d 2 . Dry capsule septicidal (Rhododendron) 138. R. CALIFORNICUM. 



3 . Apetalous without petals. 



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



the ovary containing 1-2 seeds each. 



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

 and 1-seeded ; styl^ 1, stigmatic down the side (Nyssd) ; fertile pe- 

 duncles 



2-5 flowered 9. NYSSA MULTIFLORA. 



Single-flowered and peduncle short and downy. 



110. NYSA OGECHE. 



Two or more flowers 9. N. MULTIFLORA. 



eZ 2 . Ovary superior free from the calyx. 



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

 arranged in heads, which are 



Solitary 13. PLATANUS OCCIDENTALS 



2-7 together in a moniliform spike 135. PLATANUS RACEMOSA. 



e 2 . Stipules not sheathing the stem or none. 

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

 ff. Fruit a double samara (Acer). 



h. Leaves simple and palmately veined ; flowers appearing 

 i. With the leaves in pendulous corymbs. . .7. A. SACCHARINUM. 

 i. 2 Before the leaves in short umbels ; young fruit wooly 



26. A. DASYCARPUM. 



7i 2 . Leaves compound . . 54. A. NEGUNDO. 



gr. 2 Fruit a 1-celled and 1-seeded samara (Fraxinus). 

 h. Samara terete at base ; leaflets petiolulate 



New growth smooth 10. F. AMERICANA. 



New growth pubsecent 31. F. PUBESCENS. 



7i 2 . Samara broad at base 62. F. SAMBUCIFOLIA. 



/ 2 . Ovules single in each of the 1 or 2 cells of the ovary. 



gr. Anthers opening by uplifted valves ; stigma single and entire 



(Lauracece) flowers 

 h. Perfect ; leaves evergreen ; calyx lobes 



Persistent (Persea) 113. P. CAROLINENSIS. 



Deciduous ( Umbellalaria) 159. U. CALIFORNICA. 



