40 WOODY PLANTS OF MASSACHUSETTS. 



Sterile flowers only in catkins. 4. 



Both sterile and fertile flowers in catkins. 5. 



( Leaves simple ; nuts in a cup. 49. Oak Family. II. 



I Leaves pinnate ; nuts not in a cup. 51. Walnut Family. IV. 



I 



Seeds with a tuft of cotton ; fertile and sterile flowers on different plants. 



54. Willow Family. VIII. 

 Seeds without a tuft. 6. 



{Leaves palmate ; both fertile and sterile flowers in globular catkins. Plank 

 Family. VII. 

 Leaves not palmate. 7. 



! Fruit woody, or membranous or winged. 52. Birch Family. V. 

 Fruit a dry berry or nut, not winged. 8. 

 Fruit a fleshy, compound berry. Mulberry Family. IX. 



■s. 



Nut more or less covered or concealed. 50. Hornbeam Family. 111. 

 Nut naked. 53. Wax Myrtle Family. VI. 



{Leaves opposite. 10. 

 Leaves alternate. 20. 

 Leaves wanting. Cactus Family. XXV. 



PLANTS WITH OPPOSITE LEAVES. 



.„ $ Flowers with a calyx, and a corolla of 1 petal, or with no corolla. 11. 

 Flowers with a calyx, distinct or obscure, and a corolla of many petals. 15 . 



11 



Corolla wanting. 12. 

 Corolla of 1 petal. 13. 



\ 



12 < Leaves simple; fruit a double samara or key. Maple Family. XXXIII. 

 '' ( Leaves pinnate ; fruit a single samara or key. Ash Family. XV. 2. 



C Stamens 4 ; calyx and corolla 4-parted ; ovary 2- or 4-celled. 58. Mad- 

 13. 1 der Family. XVII. 



( Stamens 4 or 5 ; calyx and corolla 5-parted ; ovary 3- or 5-celled. 14. 



f Corolla tubular, often irregular; style thread-like. 59. Honeysuckle 

 14 ! Family. XX. 



' j Corolla wheel-shaped, regular; style almost wanting. 61. Elder Fam- 



ily. XIX 

 15. f 



Stamens fewer than 10. 16. 



Stamens more than 10 ; style one. 78. Rock Rose Family. XXXVII. 



! Stamens more numerous than the petals. 17. 

 Stamens as many as the petals. 18. 

 Stamens once, or several times, 3, stigmas 3. 78. 



._ ( Fruit a leathery, prickly capsule. Horse Chestnut Family, p. 479. 

 ' \ Fruit a double samara or key. Maple Family. XXXIII. 



( Stamens opposite the petals ; berry above the obsolete calyx. 76. Vine 

 18. J Family. XXX. 



( Stamens alternate with the petals. 19. 



{Calyx beneath 2 or 3 inflated capsules. Bladder Nut. XXXII. 1. 

 Calyx indistinct, surmounting a 2-celled drupe. Cornus Family. XXII. 

 Calyx evident ; flowers in terminal panicles ; berry fleshy . Pkim. XV. 1. 



