Floristik, Geographie, Systematik etc. 205 



viewed "en face"; the stomata have no subsidiary cells and occur 

 only on the dorsal face. The chlorenchyma represents an almost 

 homogeneous tissue of roundish cells, except near the margins of 

 the blade in which typical palisades are developped. Even the 

 midrib has no support of mechanical tissue, but is embedded in a 

 large, thinwalled parenchyma, a water-storage tissue. It deserves 

 notice that the midrib has an open endodermis-like sheath, while 

 the lateral veins are surrounded by typical, and perfectlj'^ closed 

 parenchyma-sheaths. Theo Holm. 



Holm, T., Medicinal plants of North America. 11. Gaiiltheria 

 procnmhens L. (Merck's Report XVII. p. 1—3. f. 1— UJanuary 1908.) 



The oil ^^ Oleum GauUheriae''' is obtained by distillation ot the 

 leaves, and consists almost entirely of methyl salicj^late, nearly 

 identical with the volatile oil of Betiila. Much has been written 

 about the name as being misspelled, and some authors have for 

 instance adopted the name Gautiera ; however if the name should 

 be changed at all, the correct orthograph3^ would be Gaultiera, since 

 it appears from the records that the name of the Canadian physician 

 was written Gaultier. The plant has an extensivel}^ creeping, wood}^ 

 rhizome from which numerous aerial shoots are produced in a 

 Short distance from each other; the shoots live seldom more than 

 two years. The roots have a very distinct exodermis of which the 

 outer and lateral cell walls are heavily thickened; the increase in 

 thickness is very slight, depending upon the formation of a very 

 few layers of secondary cortex and of a little secondary hadrome. 

 None of the roots were found to be mycorhizae. In the old rhizomes the 

 epidermis becomes thrown off, but is replaced by a thickwalled hypo- 

 derm; the cortex is collapsed, while a pericycle of thickwalled 

 stereome, and several strata of cork Surround the stele. The stem 

 above ground has a persisting epidermis, but no hypoderm; cork 

 develops, as in the rhizome, directly inside the stereomatic pericycle. 

 The structure of the leaf-blade is bifacial; the cuticle is perfectly 

 smooth, and the stomata have generally two subsiding cells parallel 

 with the Stoma. There is a typical palisade tissue, but no sclerotic 

 cells were observed, which otherwise are so frequently met with 

 in the other genera of Ericaceae. No coUenchyme was observed in 

 the leaf, but some few strata of stereome accompanying the veins. 



Theo Holm. 



Holm, T., Medicinal plants of North America. 12. Liquidamhar 

 styracißua L. (Merck's Report. XVII. p. 31—34. f. 1—21. Febr. 1908). 



The baisam known as "Storax" is derived from Liquidamhar 

 orientalis, while the so-called "Copalin baisam" is jaelded by L. 

 styracißua, Sweet Gum. According to W. L. Harrison these pro- 

 ducts are identical, except that the Copalin baisam contains no 

 water mechanically mixed with it. The structure of the very peculiar 

 flowers is described, also the foliage and the seedling. The anato- 

 mical structure shows many points of interest in regard to the pre- 

 sence of resiniferous ducts, and also in regard to the structure of 

 the veins in the leaf. 



In the young roots the location of the resiniferous ducts (four 

 in all) may be readily observed to be in the leptome (the prim.ary), 

 and although the roots increase in thickness no additional ducts 

 become developed. The hj^pocotyl has several layers of cork, but 



