336 Angewandte Botanik 



tj^ 



and ^'■ellow. and the juice ot the whole plant has proved an excel- 

 lent remed}' for the skin-disease caused by Rhus Toxicodendron ; 

 being applied in the same way as penny-royal, mentioned in this 

 Report (April 1919). — Several figures illustrate the seedling. the 

 mature plant, and the anatomy, At the seedling-stage the root- 

 system consists of a number of long, secondary roots surpassing 

 the primary in length; all these roots become soon replaced bj' 

 much stronger ones, which push out form the lower nodes of the 

 stem. While no secondary formations appear in the roots of the 

 seedling, those of the mature plant become quite thick, especiallj' 

 at the bases, and contain much thick walled libriform, beside a ty- 

 pical pith. In respect to the stem-structure, the long hj^pocotyl ot 

 the seedling shows a typical endodermis surrounding a stele of 4 

 primary, collateral mestome-strands, separated from each other by 

 broad rays of meristematic tissue, in which scattered Strands ot 

 leptome become developed, but no libriform; a like structure recurs 

 in the apical internodes ot the mature plant, while in the basal 

 stem-portions, which are generally quiten smaller, interfascicular 

 tissue gives rise to deep raj'-s of libriform, and the innermost ves- 

 sels, annular and spiral are actually located in the pith, a structure 

 that seems characteristic of various species of the genus. 



The leaf-structure is partly dorsi ventral, the stomata being 

 distributed over both faces of the blade, while the chlorenchyma 

 exhibits a ventral palisade-tissue, and a dorsal pneumatic. The 

 midvein is composed of 3 collateral mestome-strands with an endo- 

 dermis on the leptome-side. Theo Holm. 



Holm, T., Medicinal plants of North America. 6 7. Xanthor- 

 rhisa apiifolia L'Her. (Merck's Report. XXI. p. 323—326. f. 1 — 17. 

 Dec. 1912. New York.) 



This plant was formerly ofiPicial, the bark of the stem and rhi- 

 zome, including the roots, being the part used. It contains berbe- 

 rine, which occurs as a golden-yellow liquid in the cell-lumen of 

 nearly all the young tissues, but not in the leptome; in the old 

 cells the berberine forms an incrustation on the cell- wall, especially 

 visible in the elements of the hadrome, of the stereome and the 

 libriform. The plant is described and figured, and the presence 

 of a long, creeping rhizome deserves notice, since this has been 

 overlooked by other authors. Secondary formations appear at an 

 early date in the roots. 



In regcird to the rhizome the stolons have cork, which develops 

 from the outermost Stratum of cortex; a t5'-pical endodermis, and a 

 parenchymatic pericycle of about 3 layers Surround a circular band 

 of many collateral mestome-strands, separated from each other by 

 strata of libriform; a corresponding structure characterizes the stem 

 above ground. The leaf-structure is dorsiventral; the midrib con- 

 sists of 4 mestome-strands, arranged so as to form an open arch, 

 while the caracteristic point of the petiole contains a circular band 

 of about 20 mestome-bundles surrounding a broad pith. 



Theo Holm. 



A-tisgeseben: S A.pril 191S. 



Verlag von Gustav Fischer iu Jenjk. 

 Buchdruckerei A. W. Sijthoff in Leiden. 



