THE GROWTH-FORMS OF THE FLORA OF NEW YORK 
AND VICINITYi 
Norman Taylor 
There has recently appeared in a work on the flora of New York,^ 
an account of the relation between climate and the vegetation in 
which the length of the growing season was used as the chief tem- 
perature factor. This was done for the reason that it seemed to 
account for the distribution of the flora more closely than any other 
ascertainable temperature factor. While it is difficult to conceive of 
any climatic agency, such as the number of frostless days, the maxi- 
mum or minimum temperatures, or the accumulated heat units, as 
actually controlling the distribution of the flora, yet it is a matter of 
common observation that temperature does affect vegetation and its 
distribution. How, then, are we to measure the effect of climate, 
and particularly temperature, on plant life? All of the older methods, 
including the one used in the flora of the vicinity of New York, 
have studied climate as a rather distinct entity, and then imposed a 
somewhat rigid, usually instrumentally correct scheme, on a com- 
plex aggregate like a local flora. All such schemes require con- 
siderable wrenching of the purely climatic factors on the one hand, 
as they certainly do of the assumed vegetative response on the other. 
Until recently, and with the possible exception of Merriam's ''Life 
Zones," all studies of the effect of temperature on plants were of this 
type. They were essentially attempts to explain the facts of plant 
distribution by measured temperatures or heat units or frostless days 
or by some combination of these methods. 
Raunkiaer^ has studied temperature factors from an entirely 
different viewpoint. His idea, briefly, is that we must study climate, 
1 Brooklyn Botanic Garden Contributions, No. 9. 
2 Taylor, N. Flora of the vicinity of New York: A contribution to plant 
geography. Mem. N. Y. Bot. Garden 5: 1-683. ^9^5- See pp. 33-36. All the 
statistics and figures used in this paper may be verified in that book. The nomen- 
clature of the present paper is essentially that of the Gray's Manual. 
^ A fairly complete account of Raunkiaer's system, with a bibliography, may 
be found in Journ. Ecol. i: 16-26. 1913. 
23 
