Flora of the Palonsc Region 



BRANCH SPERMATOPHYTA. 



Highly organized plants, mostly producing flowers and always 

 producing seeds, each of which contains a young plant (the em- 

 bryo) usually composed of a stem-like structure (the caulicle or 

 hypocotyl), one or more rudimentary leaves (the cotyledons) and 

 a terminal bud (the plumule or epicotyl):macrosporangia (ovules) 

 usually borne on the side or face of an open or closed modified 

 leaf (the carpel): microsporangia (anther-sacs) on the end or side 

 of a modified leaf (the filament) and bearing numerous micro- 

 spores (pollen grains). 



Class 4. GYMNOSPERMAE. 



Ovules (macrosporangia) naked, not enclosed in an ovary, 

 usually on the face of an open scale but sometimes on the axis, in 

 which case the scale is rudimentary or wanting: stigmas none: 

 cotyledons mostly several in a whorl, occasionally only two' per- 

 ianth none. 



Order 7. CONIFERAE. 



Stem branching freely: leaves entire, relatively small, linear or 

 reduced to scales: ovules naked. 



Family 7. PINACEAE. 



Resinous trees or shrubs, mostly with evergreen narrow entire 

 or scale-like leaves: pollen-sacs and ovules borne in separate 

 spikes (aments); ovules solitary or several together on the surface 

 of a scale, which is in the axil of a bract in most genera: fruit a 

 cone with numerous several or few, woody papery or fleshy 

 scales: seeds wingless or winged. 



Scales of the cone numerous: leaf-buds seal}'. 



Cone-scales woody: leaves needle-shaped, 2-5 in a sheath. 



12. Pinus. 

 Cone-scales thin: leaves filiform, scattered or clustered, not in sheaths. 



Leaves clustered on very short brauchlets, deciduous. 



13. Larix. 

 Leaves scattered, persistent. 



Brauchlets smooth; leaf-scars not prominent: bracts longer than 

 the cone-scales. 

 Cones erect; scales deciduous: leaves sessile. 



14. Abies. 

 Cones pendulous; scales persistent: leaves petioled. 



15. PSEUDOTSUGA 

 Brauchlets rough from the prominent persistent leaf-bases: bracts 



smaller than the scales. 16. PlCEA. 



Scales of the cones few (3-12): leaf-buds naked, 17. Thuya. 



