Angewandte Botanik. 557 



a hypoderm which becomes the mother-tissue of a thick cork. There 

 are, furthermore, several strata of collenchyraa, which Surround 

 the cortex proper, but no endodermis was observed. An almost 

 completely closed, stereomatic pericycle encircles the stele, in which 

 porous tracheids are especially abundant, beside libriform. The leaf- 

 strueture is bifacial and meet here with small, glandulär hairs, 

 which are pluricellular. The stomata are partly covered by the 

 crests of the very thick cuticle, but lack subsidiary cells. In respect 

 to the chlorenchyma this is differentiated as a ventral Stratum of 

 high palisades with scattered cells containing crystals; the pneu- 

 matic tissue is verjr open, and composed of irregularty branched 

 cells in about five layers. Hypodermal collenchyma accompanies 

 the midrib and the stronger lateral, while the pericycle is poorly 

 developed, and barely to be called stereomatic. A thinwalled, color- 

 less parenchyma surrounds the midrib in which there is a broad, 

 arch-shaped, collateral mestome-bundle, a structure which recurs in 

 the petiole. 



In the cotyledons the cuticle is thin, and perfectly smooth; a 

 few stomata were observed on the ventral face, and the veins are 

 embedded in chlorenchyma, thus lacking the collenchyma and the 

 thinwalled parenchyma. Theo Holm. 



Holm, T., Medicinal plants of North America. 32. Samba- 

 cus canadensis L. (Merck's Report. XVIII. p. 259—262. fig. 1 — 11. 

 Oct. 1909.) 



Formerly this species of Sambucus was included in the U. S. 

 Pharmacopoea, while the flowers are still included in the British. 

 The active principles of the American species have not so far been 

 determined, but are probably similar to those of the European. 

 Common to both species (5. Canadensis and 5. nigra) is the fact that 

 the flowers yield their active principles to water by infusion; and 

 when distilled they yield a small portion of volatile oil, on cooling 

 assuming a butyraceous consistency. The berries are nearly inodo- 

 rous, of a sweetish, acidulous taste, due to the presence of saccha- 

 rine matter and malic acid; the juice is stained violet by alkalies, 

 bright red by acids, and the coloring matter is precipitated blue by 

 lead-acetate. 



The seedling, the stoloniferous rhizome, and the internal struc- 

 ture of the vegetative organs is- described and illustrated. In the 

 seedling are noticed a Short, primary root, a very short hypocotyl, 

 and two, epigeic, oblong-ovate cotyledons. The first leaves of the 

 plumule are simple, opposite, broadly ovate, and coarsely serrate, 

 while in S. nigra these leaves are cordate, and frequently trifoliolate. 

 The root-structure is very simple, since there is no exodermis, and 

 no "reseau de soutien", otherwise not uncommon in this family; 

 Crystalline sand was observed in the secondary cortex, and this 

 type of crystals occurs, furthermore, in the leaf and stem. In regard 

 to the stem-structure it is interesting to notice the absence of secre- 

 ting ducts in the first season, while calcium Oxalate is well repre- 

 sented in the first internodes, and only in the shape of crystalline 

 sand. In the mature shoot the cork develops from a hypodermal 

 collenchyma, and the pericycle contains scattered Strands of ste- 

 reome; beside these there are, furthermore, many large groups of 

 stereome on the inner face of the primary leptome, but of secondary 

 origin. Secreting ducts and cells with crystalline sand abound in the 



