Floristik, Geographie, Systematik etc. 507 



vable to the naked eye as minute, transparent dots. The lateral cell- 

 walls of epidermis show local thickenings; the stomata have no 

 subsidiar^^ cells; the midrib consists of two mestome-bundles which 

 have partU^ fused together laterally; the lateral veins are surrounded 

 by parenchyma-sheaths. The stem above ground shows an endoder- 

 mis and a sheath of stereome. Theo Holm. 



Hoim, Theo, Studies in the Cyperaceae. XXV. Notes on Carex. 

 (Am. Journ. of Sc. XXIII. p. 422—432. f. 1—13. June 1907.) 



A discussion of the systematic position of Carex capitata L. , and 

 C. holostoma Drej., with notes upon their anatomical structure. 

 Carex capitata is a true Vignea^ but monostachyous; the small roun- 

 dish, androgynous spike with the greenish, wingless, membranaceous 

 perigynia spreading at maturity, and the straight beak with hyaline 

 orifice are characters that are seldom met with among the Vigneae. 

 It represents a „forma hebetata", but the writer has been unable to 

 detect any analogies in the external structure by which it might 

 be associated with some of the more evolute tj'^pes among the 

 Vigneae. For this reason the writer has prefered to place it in a 

 grex of its own: ■ Microcephalae ^ preceding Cephalostachyae [C.foetida 

 cet.) and Sphaerostachyae (C. incurva). It shows an enormous wide 

 geographical distribution, extending throughout the northern hemi- 

 sphere of both worlds, besides that it occurs also in South America: 

 Argentina and Tierra del Fuego. 



Very peculiar is the structure of epidermis of stem and leaves; 

 the outer cellwalls are heavily thickened and extended into large, 

 clavate papillae surrounding the stomata. Such protected stomata 

 have been observed in several species of the more evolute tj^pes of 

 Vigneae and Carices genuinae, but not, so far, in any of the „formae 

 hebetatae. In regard to Carex holostoma, this species is as a rule 

 placed next to C. alpina, although it differs in several respects from 

 this species; C. holostoma has, as a matter of fact a terminal stami- 

 nate spike instead of a gymnaecandrous as in C. alpina. The structure 

 of the perigynium is more like that of C. stylosa C. A. Mey., and of 

 C. Raynoldsii Dew., hence the writer prefers to place the species 

 near C. stylosa, but somewhat remote from C. alpina. 



Theo Holm. 



Koernicke, M. und F. Roth. Eifel und Venn. Eine pflanzen- 

 geographische Skizze. (Verlag von G. Fischer in Jena. 1907. 

 Vegetationsbilder von Karsten u. Schenck. V. Reihe, Heft 1 u. 2.) 



Die Einleitung zu dem vorliegenden Doppelheft der schon längst 

 rühmlich bekannten „Vegetationsbilder", einer durch ihren Inhalt 

 wie ihre bildnerische Ausstattung gleich ausgezeichneten und inter- 

 essanten pflanzengeographischen Skizze, enthält zunächst einige 

 allgemeine Ausführungen über die geographische Lage und Gliede- 

 rung der Eifel und des Hohen Venn, über das geologische Gepräge 

 des Gebietes sowie über die klimatischen Verhältnisse. Die Eifel 

 trägt einen gebirgigen Charakter, der insbesondere durch die älte- 

 ren und jüngeren vulkanischen Bildungen (Hocheifel und Gebiet 

 des Laacher Sees) bedingt wird; das Venn dagegen, welches ein 

 erheblich anderes geologisches Gepräge aufweist und sich als Ver- 

 bindungsglied zwischen Eifel und Ardennen darstellt, bietet auf 

 seiner Hochfläche, trotz beträchtlicher Erhebung, keine gebirgige 

 Erscheinung dar. Das Venn ist eines der regenreichsten Gebiete 



