XYLEM ANATOMY OF SOPHORA (LEGUMINOSAE) IN RELATION TO HABIT

Cumbie , B. G., and Dan Mertz . (U. Missouri, Columbia.) Xylem anatomy of Sophora (Leguminosae) in relation to habit . Amer. Jour. Bot. 49(1): 33–40. Illus. 1962.—A comparison of 8 tree, shrub, and herbaceous species of Sophora showed considerable variation in structural organization of the secondary xylem in relation to habit. A reduction in duration of cambial activity has been accompanied by a decrease in conspicuousness of storied structure, more frequent arrangement of vessels in multiples, the formation of narrower rays, and a striking reduction in amount of axial xylem parenchyma. On the other hand, relatively minor changes in size of xylem elements have resulted from decreased cambial activity, as shown by comparing the first-formed secondary xylem elements of woody and herbaceous species. In many structural features, shrubs were found to be more or less intermediate between the tree and herbaceous species, at least in the early stages of development. These observations indicate that the often repeated generalization that the organization of herbaceous stems resembles that of the first year's growth in closely related woody species is not always applicable.