84 Forest Club Annual 



I. Stems mostly 1 inch long; cotyledons ^4 to 1 inch long, 



smooth or serrulate on 3 sides, triangular in cross-section. 



Pinus 



a. Cotyledons smooth, leaves serrulate. 



1. Cotyledons 3 to 5, 1 inch long; stem y 2 inch long, 



slender. P. contorta 



2. Cotyledons 5 to 8, 1 inch long; stem 1 inch long, red- 



dish at base. P. ponderosa 



3. Cotyledons 6 to 10, 1 inch long; stem 1 to \y\ inches 



long, slightly reddish ; leaves only slightly serrulate. 



P. austriaca 



b. Cotyledons and leaves both more or less serrulate. 



1. Cotyledons 3 to 5, remotely serrulate, ^4 inch long; 



stem 1 inch long, thin, buff colored or light reddish; 

 leaves distinctly serrulate on 2 edges. P. divaricata 



2. Cotyledons 4 to 6, 1 inch long, slightly serrulate ; stem 



24 inch long, pinkish at base. P. sylvestris 



3. Cotyledons 6 or 7, remotely serrulate, 24 inch long; 



stem 1 inch or longer, dark red at base, very remotely 

 spinulose ; stomata with indistinct white markings. 



P. resin osa 



4. Cotyledons 7 or 8, 1 inch long; stem 2 inches long, 



light reddish. P. taeda 



5. Cotyledons 8 or 9, 1 inch long; leaves l / 2 inch long; 



stem 24 inch long, thick, yellowish brown; stomata 

 with indistinct white markings. P. ftexilis 



6. Cotyledons 7 to 10, ^ to 1 inch long; stem 1 to 2 



inches long, reddish green at base. P. strobus 



7. Cotyledons 10, 1)4 inches long; stem 24 to 1 inch long, 



brownish to purplish; leaves 24 to 1 inch long, sharp 

 pointed, bluish bloom. P. edulis 



II. Stem usually less than 1 inch long; cotyledons usually 



about y 2 inch long, triangular in cross-section ; leaves flat- 

 tened or 4-sided, white stomatal markings, 

 a. Cotyledons not flattened ; primary leaves 4-sided, serru- 

 late on 4 sides. Picea 



1. Cotyledons 5 to 7, J /2 inch long; stem ^ to 1 inch long, 



reddish at base ; scattered stomata. P. engelmanni 



2. Cotyledons 6 to 8, y 2 inch long, scattered stomata : 



