The Trees of Vermont 213 



ee. Growth rings (cross) narrow; resin ducts (cross) not 

 numerous, the epithelium cells thick-walled, 



Picea rubra, p. 217. 



cc. Resin ducts and resin cells (cross) not scattered, but more or 



less confluent and forming tangential lines ; fusiform rays 



{tangential) absent; rays (radial) chiefly or zvholly zuithout 



tracheids. 



d. Wood with odor like cedar oil, especially when wet ; heart- 

 wood purplish to red-brown, with yellow-white sapwood, its 

 smoothed surface dull; rings (cross) wavy and sinuous, 



Juniperus virginiana. 



dd. Wood odorless, even when wet ; heartwood dull yellow- or 



gray-brown, differing only in shade from the sapwood, its 



smoothed surface greasy or waxy; rings (cross) regular, 



not wavy nor sinuous Taxodium dlstichum, p. 223. 



bb. Resin ducts (cross) absent and resin cells (cross), if present not 

 prominent, not forming conspicuous, tangential lines ; fusiform 

 rays (tangential) absent. 



c. Wood with mild odor like cedar oil, especially when wet ; 

 heartwood distinct in shade from the sapwood; rings (cross) 

 wavy ; wood spongy, difficult to cut smoothly across the grain ; 

 ray tracheids (radial) zvholly absent, 



Thuja occidentalis, p. 221. 



cc. Wood without odor of cedar oil, even when wet ; heartwood 



not distinct in shade from the sapwood; rings (cross) not 



wavy ; wood not spongy, easy to cut smoothly across the grain ; 



ray tracheids (radial) present. 



d. Transition (cross) from spring wood to summer wood 

 abrupt ; wood light red-brown, with rancid odor, especially 

 when wet, cross-grained, splintery and hard to work ; resin 

 cells (cross) prominent, but not numerous; ray tracheids 



(radial) prominent Tsuga canadensis, p. 219. 



dd. Transition (cross) from spring wood to summer wood 

 gradual ; wood yellow- white to pale brown, odorless, even 

 when wet, straight-grained, not splintery and easy to work; 

 resin cells (cross) absent; ray tracheids (radial) not promi- 

 nent, occasional Abies balsamea, p. 221. 



