206 Floristik, Geographie, Systematik etc. 



no endodermis, and the pericj^^cle is only represented by four, 

 isolated groups of stereome. The stele consists of collateral mestome- 

 strands forming a compact cylinder, and close to the inner face of 

 the hadrome, and very near the primordial vessels are two wide 

 ducts. In the fruit-bearing branch we notice a peripheral cork, 

 bordering on a collenchymatic cortex, and a stereomatic, broken 

 pericycle. Small druids of calcium Oxalate, and resin were observed 

 in the secondary leptome, besides that numerous ducts are located 

 on the inner face of the hadrome. The long petiole is traversed by 

 fine concentric (perileptomatic) mestome-strands, each with a resini- 

 ferous duct in the center. The leaf blade shows stomata on both 

 faces; they are level with the epidermis and have one pairofsubsidiary 

 cells parallel with the Stoma; there is a distinct palisade tissue and 

 an open pneumatic tissue. In the angles of the larger veins on the 

 dorsal face of the blade are tufts of hairs, which evidentl}- serve 

 as "domatia". Hypodermal collenchyma accompanies most of the 

 larger veins, forming prominent ridges. Very peculiar is the structure 

 of the midrib and the secondaries; each of these is actually com- 

 posed of three distinct mestome-strands, which have fused together 

 so as to form an apparentl}^ Single "concentric", in this case "peri- 

 leptomatic" Strand with three ducts in the center, one to each Strand. 

 But in some of the secondaries the fusion is imperfect, thus 

 we might readily observe one large and two small, separate mestome- 

 strands instead of but one. The tertiary veins contain mostly one 

 Single, collateral mestome-bundle, surrounded by a tj^pical paren- 

 chyma-sheath. Van Tieghem's Suggestion to remove the genus 

 together with Altingia from Hamamelideae is no doubt the most 

 natural. Theo Holm. 



Holm, T., Medicinal plants of North America. 13. Cypripediiini 

 pubescensW iWd. (Merck's Report XVII. p. 60—62. f. 1—9. March 1908.) 



The drug called ^'•Cypripedinm. U. S." is the dried rhizome and 

 roots of C pubescens or C. parvifloruni Salisb. , the former of which 

 is the most frequent. The rhizome is somewhat aromatic when 

 fresh, and of a peculiar bitter sweetish taste; it contains a resinoid 

 "cypripedin". The structure of the roots agrees with that of Mono- 

 cotyledones in general, being rather slender and containing a normal 

 Stele. In the rhizome we notice a thickwalled cortical parenchyma 

 which surrounds the stele directly, no endodermis or pericycle being 

 developed. There is a compact mass of mostly leptocentric mestome- 

 strands, but no pith. A very different structure is exhibited by the 

 stem above ground in which a stereomatic pericycle encloses a 

 circular band of simply collateral mestome-bundles of which the 

 leptome borders on the pericycle; beside this peripheral band of 

 mestome-bundles there are two others located nearer the center ot 

 the stem, but not regularly concentric. A thinwalled pith occupies 

 the center of the stele. In regard to the leaves the structure is 

 bifacial so far as concerns the distribution of the stomata, while the 

 chloren chyma represents a homogenous tissue of four layers of 

 rectangular cells (in cross-section). Hypodermal collenchyma and a 

 few strata of stereome inside this accompany the stronger veins, 

 and there is, furthermore, some thinwalled water-storage tissue 

 around these veins. Large cells containing raphides abound in the 

 chlorenchyma. The drug is frequentl}?- mixed with rhizomes and 

 roots of Polygala Senega and Hydrastts, but the anatomical structure 



