FAMILY KEY 



A. GYMNOSPERMS (Cone Bearers) — Trees or shrubs, evergreen (except Zam), 

 cone-bearers (except Taxus ahd Juniperus) ; leaves either needles or scales ; 

 ovules not inclosed in an ovary. 



B. Fruit a red berry; leaves complanate, scattered, needle-like, flat, sharply 

 acute or acuminate ; ovule i ; flowers dioecious, solitary, axillary. 



Taxaceae (p. 29) 

 BB. Fruit either a woody cone or a bluish berry ; leaves not agreeing with the 

 above in all points ; ovules 2 to several on each scale ; flowers mostly monoecious, 

 mostly several grouped together forming cones ; cones usually axillary. 



PiNACEAE (p. 29) 



AA. ANGIOSPERMS (Ovary Plants) — Trees or shrubs or herbs, mostly not 

 evergreen ; inflorescence rarely conelike ; leaves rarely needles or scales ; ovules 

 inclosed in an ovary. 



C. Monocotyledons — Herbs or one a vining shrub (SmUax), some leafless and 

 floating ; leaves parallel-vtined, or the chief veins from the base, or i-veined, or 

 none ; flower parts in 3's, rarely in 4's, never in s's ; wood usually in bundles 

 scattered throughout the stem ; cotyledon i . 



D. Plants free-floating; body thalloid, without a distinct stem or leaf; roots 



unbranched or none. Lemnaceae (p. 51) 



DD. Plants not free-floating, or if so having leaves ; leaves usually present ; stem 



present or the leaves tufted at base ; roots present, usually branched. 



E. Leaves narrow, linear or grasslike, • GROUP i (p. 7) 



EE. Leaves none, or mere scales, or at least some of them too wide to be linear. 



GROUP 2 (p. 9) 



■ CC. Dicotyledons — Herbs or shrubs or trees, never leafless when floating; 



leaves netted-veined, or the chief veins from the base, or i-veined, or none; 



flower parts rarely in 3's, mostly in 4's or 5's ; wood usually in a circle or in 



several concentric circles about a central pith; cotyledons 2. 



KEY TO THE DICOTYLEDONS (p. 10) 



GROUP 1 — Monocotyledons with narrow leaves 



A. Plants growing in salt water near the low-tide line, submerged in the sea; 

 leaves 3-20 dm. long, flat or folded lengthwise. Naiadaceae (p. 34) 



AA. Plants not growing near the low-tide line of the sea, although sometimes 

 growing along seashores ; leaves often not as above. 



B. Plants submerged in fresh or saline waters; leaves opposite or whorled, not over 

 5 mm. wide. 

 C. Leaves toothed at margin, 0.4-2 mm. wide, 8-25 mm. long. 



Naias in Naiadaceae (p. 34) 



7 



