360 YOUNGKEN— ON THE MYRICACEAE 



Myrica inodora, Bartram 

 A shrub or small tree attaining a height of 6 mm., with a maximum 

 trunk diameter of nearly 9 cm(lO). The first branches are ascending, 

 often straight with a white bark. The branchlets of recent growth are 

 smooth and reddish brown with a few longitudinally elongated lenticels, 

 5 mm. long. Those of the second year's growth are ash brown in color 

 and show lenticels 5 to 7 mm. long. 



Compfonia asplenifolia, L. Alton 



A round-headed low shrub growing to the height of 1 to 1.25 m. 

 The main aerial stem is ascending in habit and grows to the length of 

 about 3 dm. It frequently bifurcates into two crooked branches which 

 bear numerous branchlets toward their summit. The recent shoots 

 are greenish yellow to reddish brown in color and covered with long 

 white hairs and minute yellow shining glands which are always more 

 numerous toward the ends of the branches. Usually one or two thin 

 special branches are borne at the ends of these which bear catkins. These 

 die after the descent of the pollen but often remain on the shoots until 

 the next season, especially in localities where the plant is well protected 

 from winds. The branchlets of the 2d and 3d year's growth are of a 

 steel to reddish-brown color, somewhat pohshed and show scattered 

 transversely-elongated lenticels which vary from .5 to 1 mm. in length. 

 The older branches become darker in color but retain their reddish aspect. 

 These are usually quite crooked and show narrower transversely elon- 

 gated lenticels from 1-3 mm. in length. The main stem shows a dark 

 and considerably cracked cork. The underground stem is extremely 

 crooked and creeps through the soil for a long distance giving rise to 

 numerous branches and suckers at its various nodes. The suckers branch 

 downward then upward forming inverted arches (Plate 82, Fig. 4). It 

 possesses relatively few lenticels which are not raised like those of the 

 aerial stems. Some of the underground stems bear tubercles, others 

 thin fibrous roots upon which the tubercles are clustered. 



Histology 



Under this sub-caption the microscopic peculiarities of stems of 

 primary growth, showing primary structure, will first be considered from 

 a general standpoint. Those of aerial and subterranean branches of 

 secondary growth showing secondary structure will be specifically treated 

 in the following order: (a) M. cerifera, (b) M. Carolinensis, (c) M. 

 Macfarlanei, (d) M. Gale, (e) Comptonia asplenifolia. 



