STOIiRS AGRICULTURAL ESrERIMENT STATIOJi. 327 



ANALYTICAL KEY 



METHOD or USE 



Despite ihe fact that tlie appearance of the bark and tlie iiieUiod 

 of branching are ahnost exclusivel)' clepenclecl upon by tlie expeii- 

 enced woodsman in recognition of species, those characters are 

 difficult of precise description and not adapted to use in a key. 'Jdie 

 twigs therefore ivith the scaly buds and leaf-scars are used, as a 

 basis of the following keys. The "woi'd '"twig" in the seiisi.' hei'c 

 used, it should be remembered, denotes tlie growth of tlie jiast 

 season only, and the word "bark" refers to the bark of the trunk 

 and older lind)S and not of flic twigs or bi'anchlets. The student 

 should read the introchrction and note the limitation ot terms and 

 eliaracters itsed in tlie following pages. 



Tiefore attempting to identifv an unknown tree it is necessary 

 to ]ia\e good material to work with. Care should Ijc taken that 

 the twigs selected are normal in. appearance, being neither abnnr- 

 uuiUv stunted in growth nor unusually elongated as are twigs on 

 young sprouts. Frequently the sj)ecies ma\' be detei'inined by an 

 inspection ot the twigs alone but notes on the chai-acier of the 

 bailv and the habit of groM'tb as well as S])eeinieus of the fruit 

 will generally Ix; found useful and siunetimes necessai'y. 



In the key a i-hoice is giyen betu'cen two jiaragrapbs pi'eet'iled 

 ]>y tlie sanu:; nundier. This choice leads to a new uundiei' or to the 

 name of the s|iecies followed liy the ])age whei'e a detaile(l 

 dt'sci'iption of the tree nmy lie found. Tbe AVbite Ash may lie 

 useil to sliow the method of procedure. Starting with A'o. f \ve 

 liaye ihe choice lietween trees with "leaNcs ]iersistent and green 

 throughout -winter" and trees witli "lea\es iiol persistent and gi'een 

 thi'oughout wintei'." AVe choose the latter and this takes us to Xo. 



11 where the decision must lie made bet\\-een "leaf-seai's o]i|iosit(> 

 or in 3's" and "leaf-scars alternate." Qlie leaf-scai's on tbe ,\sh 

 are opposite and we take the first 11 and are led to Xo. 1'^ At 



12 we liaye the alternatiye between "leaf-scars, or some of tbeni. 3 

 at a node" and "leaf-scars always 2 at a node." 'I'he lii-st ]iair 

 of contrasting characters mentioned are always tbe most im]iortant. 

 I'he constant presence in the Ash of two leaf-scars at a node is 

 sufficient to cause us to choose the second 12, and our elioice is 

 cori'olioi-ated by tbe ]iosition of the linmlle-scars and liy Hie |iresence 

 of a terminal bttd, so we pass to 13. The ujijier lateral buds of 



