The Resin Sac Pattern in the Needles of Engelmann Spruce and Blue Spruce from Southeastern Wyoming
- 1 January 1949
- journal article
- research article
- Published by JSTOR in The American Midland Naturalist
- Vol. 41 (1) , 233-254
- https://doi.org/10.2307/2422027
Abstract
The resin-containing units of both Engelmann and Blue Spruce needles consist of short sacs lying in 1 or 2 longitudinal rows along the lateral angles of the needles. They may be seen in their entirety through the surface of unsectioned needles. The length and number of resin sacs for both spp. of spruce were detd. from 1000-needle samples. Sufficient variation was found in the number of resin sacs visible in cross-sections of the needles of either spp. to indicate that in our region this characteristic is useless in distinguishing between these spruces, although it has been considered a specific difference. It is possible that the length of individual resin sacs might be of some value in distinguishing between these 2 spruces.This publication has 1 reference indexed in Scilit:
- Needle Structure as an Aid in Distinguishing Colorado Blue Spruce from Engelmann SpruceBotanical Gazette, 1931