Angewandte Botanik. 383 



of the aerial internodes shows a homogeneous structure (thinwalled), 

 we observe in the subterranean stem-portion a heterogenous pith, 

 being partly sclerified, the sclereids being very thickwalled, porous, 

 and occurring in large clumps scattered throughout the parenchyma. 

 The leaf-structure is bifacial; epidermis is on the dorsal face pro- 

 minently papillose, while long, curved, pluricellular hairs cover the 

 ventral. Large idioblasls with aggregated crystals of calcium Oxalate 

 are frequent in the pneumatic tissue, while the laticiferous ducts 

 occur in the thinwalled parenchyma which accompanies the midrib; 

 ducts were, also, noticed near the inner leptome of the midrib, 

 which shows a typical bicoUateral structure. The Holm. 



Holm, T., Medicinal plants of North America. 45. Gvindelia 

 squarrosa (Pursh) Dunal. (Merck's Report XIX. p. 310—312. fig. 

 1—10. Nov. 1910.) 



Characteristic of several of species of Gvindelia is a balsamic- 

 viscid herbage, the heads especially so before and during anthesis, 

 whence called Gum-plant in California: "■Gvindelia'^ is the name 

 of the drug, which consists of the dried leaves and flowering tops, 

 in which an alkaline principle Grindeline is contained, residing in 

 the resinous exudation. The drug is used as an antispasmodic, and 

 has, also, been employed, with asserted success, in whooping cough. 

 Several figures accompany the text, and from the anatomical 

 description the foUowing points may be mentioned. Being a plant 

 of xerophilous habit, it is stränge to notice that in the roots the 

 cortex collapses at an early stage, and becomes protected by layers 

 of cork, developed from the exodermis. — Another peculiarity 

 depends upon the presence of thickwalled stereome in the primär}^ 

 leptome, visible already in young, capillary roots; stereome occurs, 

 furthermore, in the secondary leptome of older roots. A very firm 

 structure is to be observed in the stem. The cuticle is thick, wrin- 

 kled, and epidermis very thickwalled;. the peripheral portion of 

 cortex is collenchymatic; there is a typical endodermis with a resi- 

 niferous duct outside each mestome-strand; very thick Strands of 

 stereome in the shape of arches (in transverse sections) support the 

 leptome. The stele consists of collateral mestome-bundless located 

 in a Single band, separated from each other by narrow rays of 

 parenchyma; the leptome lacks stereids, and the pith is homoge- 

 neous, with some of the cells containing small prismatic and needle- 

 shaped crystals of calcium-oxalate. The thick, somewhat coriaceous 

 leaves have stomata on both faces, distributed in small groups, 

 covering green chlorenchyma- (palisades), and separated by broad 

 Strands of large epidermis-cells, covering a parenchyma of large, 

 colorless cells, which represent a water-storage tissue. Glandulär 

 hairs, located in cavities formed by epidermis, abound on both faces 

 of the blade. The chlorenchyma consists of palisades interrupted 

 by groups of water-storage-tissue, which form sheaths around the 

 veins. There is a resiniferous duct located just outside the leptome 

 of most of the veins, but the pericycle is iaintly visible only in the 

 mediane vein. Theo Holm. 



Holm, T., Medicinal plants of North America. 46. Rhiis 

 glabra L. (Merck's Report. XIX. p. 338—340. fig. 1—12. Dec. 1910.) 



Among the true Sumachs with pinnate leaves, terminal. 



