Notes on Coniferous Seedlings 83 



com munis, and Thuya occidentalis, are American species. He 

 gives a drawing of each, but does not include a complete descrip- 

 tion. The characters used are serrulation of leaves and length 

 and number of cotyledons. He describes Larix europea, which 

 is probably very much like the L. amcricana, as having both 

 leaves and cotyledons smooth ; the drawing shows them to be 

 sharp pointed and seven in number. 



Sir John Lubbock in his book entitled "On Seedlings," Vol. 

 2, p. 548, gives a difference between Thuya occidentalis and 

 Thu\a gig ant ea, the former having two opposite primary leaves 

 and then about five whorls of three, while the latter has four 

 primary leaves opposite in pairs with whorls of three above. 

 I J in us riyida, he says, has from four to six cotyledons from l /2 

 to Y\ inch long. He described one year old seedlings of seven 

 coniferous genera but does not mention other American species. 



Charles Mohr in "Notes on Red Cedar," U. S. Forest Ser- 

 vice Bulletin 31, describes the seedling of that species (Juniperus 

 virginiana). It has two cotyledons, the primary leaves are in 

 whorls of three or rarely two, ^ inch long, rigid, sharp pointed, 

 channeled above with a sharp midrib, the stomata irregular in 

 four or five rows. 



Drawings of seedlings of southern pines are found in Bul- 

 letin 13 and of White Pine in Bulletin 22, and of many conifer- 

 ous species in C. S. Sargent's "Silva of North America," but 

 none of them are detailed enough to give much definite informa- 

 tion. In his "Manual of the Trees of North America" Sargent 

 gives the number of cotyledons in different genera as follows : 



Pinus 

 Picea 

 Larix 

 Tsuga 



Pseudotsuga 6 to 12 Chamaecy parts . .2 



Abies 4 to 10 Juniperus 2 (or 4 to 6) 



Sequoia 4 to 6 Tuniion and Taxus 2 



These points are combined as far as possible with the 

 observations made in this experiment in the preparation of the 

 following key. 



A. Cotyledons varying in number from 3 to many. 



