110 Proceedings of the O/ilo State Academy of Science 



CLASSIFICATION AND DESCRIPTION OF THE 

 SPECIES. 



.SERIES III. SPERMATOPHYTA. SEED-PLANTS. 



Subkingdom, GYMNOSPERMAE. Gymnosperms. 



Class, GiNKGOEAE. 



Order, Ginkgoales. 



Ginkgoaceae. Ginkgo Family. 



I. Ginkgo Kaempf. Ginkgo. 



Trees with deciduous, fan-shaped, dichotomously veined 

 leaves on wart-like dwarf branches. 



* Ginkgo biloba. L. Maiden-hair-tree. A large, beauti- 

 ful and hardy tree with dioecious flowers. Seed large, drupe- 

 like. Autumn leaves orange. Introduced from China and 

 Japan ; should be commonly cultivated for ornament. 

 Class, Coniferae. Conifers. 

 Order, Pinales. 



Pinaeeae. Pine Family. 



2. Pinus L. Pine. 



Resinous evergreen trees with small dwarf branches bearing 

 2-5 narrow foliage leaves ; dwarf branches and ordinary twigs 

 'Covered with scale leaves. Dwarf branches self-pruned after a 

 number of years. Carpellate cones woody, with numerous car- 

 pels. Our most important lumber trees. 



1. Dwarf branches with 5 'fohagc leaves; ovuHferous scales Httle thick- 

 ened at the tip. P. sfrobits. 



1. Dwarf branches with 2-3 foliage leaves; ovuliferous scales much 



thickened at the tip. 2. 



2. Dwarf branches with 3 foliage leaves, rarely 2 or 4. 3. 



2. Dwarf branches mostly with 2 foliage leaves some of them may be 



with 3. 4. 

 ■3. Leaves 6-10 in. long; carpellate cone oblong-conic. P. iacda. 

 ■3. Leaves 3-5 in. long; carpellate cones ovoid. P. rigida. 

 4. Twigs glaucous; resin-ducts parenchymatous ; carpellate cones 1^-3 



in. long; ovuliferous scales tipped with a prickle or small spine. 5. 

 4. Twigs not glaucous. 6. 



