8 Sierra Club Publications. 



KEY TO THE SEED PLANTS. 



OVULES NOT ENCLOSED IN AN OVARY. 



Trees or shrubs, usually with needle-shaped or scale-like evergreen 

 leaves Pine Family 



OVULES IN AN OVARY. 



FLOWERS ON PLAN OF 3; LEAVES USUALLY PAR- 

 ALLEL-VEINED. 



Ovary free from the perianth ; stamens 6 . . Lily Family 

 Ovary attached to the perianth and below it. 



Stamens 3 Iris Family 



Stamen i Orchid Family 



FLOWERS GENERALLY ON PLAN OF 4 OR 5; 

 LEAVES GENERALLY NKTTED-VEINED. 



WITH BUT ONE SET OF FLORAL ENVELOPES OR NONE. 



Flowers in catkins. Trees or shrubs. 



Dioecious ; i flower to each scale of the catkin ; fruit a many- 

 seeded pod, each seed furnished with a tuft of cotton. 

 Willow Family 



Monoecious; staminate catkins drooping; pistillate erect, cone- 

 like, with I or 2 flowers under each stiff, shield-shaped scale. 

 Alder Family 



Monoecious ; staminate flowers only in catkins ; fruit a nut in a 

 cup or burr, or a leaf-like cylindrical sheath. 

 Oak Family 



Dioecious; sterile flowers with stamens 4-parted, stamens 4; pis- 

 tillate flowers with calyx 2-lobed or wanting, ovary i-celled, 

 2-ovuied ; fruit a berry. . . Silk-Tassel Bush Family 



Flowers not in Catkins. 



OVARY SUPERIOR. 



i-celled, forming a 3-sided or lens-shaped akene, stamens 9, 



perianth of 6 divisions usually colored like a corolla. 



Buckwheat Family 



I-celled, with 2-4 ovules from the top of a central placenta, form- 

 ing a berry-like fruit containing i seed ; leaves alternate. 

 Sandalwood Family 



WITH BOTH CALYX AND COROLLA, THE LATTER OF DISTINCT 

 PETALS. 



STAMENS ON THE RECEPTACLE, BELOW THE SUPERIOR 

 OVARY. 



Stafuens numerous. 



Separate, the other floral organs also distinct ; petals sometimes 

 wanting ; flowers with the sepals 3-6, often irregular. 

 Buttercup Family 



