Contributions towards a Knowledge of the Anatomy 
of the Genus Selaginella. 
The Root. 
BY 
J. C. Th. UPHOF, Ph.D. 
With thirteen Figures in the Text. 
HE author wishes to make an attempt to give an account of the 
JL anatomy of the root of the genus of Selaginella , under which he 
includes also the so-called rhizophores. In various excellent articles in 
‘ Annals of Botany *, the anatomy of the stem, leaf, and ligule of this genus 
have been studied by Gibson, and the strobilus by Miss Mitchell. This 
leaves the root of the genus untouched. The writer has made his observa- 
tions at the Royal Botanical Gardens at Kew, where most of his studies 
have been done at the Jodrell Laboratory, and is therefore thankful for the 
kind help he received from Sir David Prain, Director of the Botanical 
Gardens, and from Mr. L. A. Boodle, Curator of the Jodrell Laboratory ; also 
to Mr. W. Emery for preparing the manuscript for publication. 
The present species of the genus of Selaginella need some consideration ; 
the author considers them as remnants of older periods (they existed already 
in the Palaeozoic Flora) in which related genera reached their highest pitch 
of development. The origin and morphological development of their organs 
will be still better understood when fossil forms have been properly studied, 
which no doubt will be the case in the near future. It has to be considered 
that Selaginellas and the present living related families are the most primitive 
forms of vascular plants, and therefore morphologically of the utmost im- 
portance. Especially in the fossil species and monstrosities of plants of 
present forms there may be some likelihood of studying the morphological 
origin of one of the most important organs of the higher plants, namely, that 
of the root. 
The present living distant relatives of the Selaginellas are the 
Lycopodiaceae and Psilotaceae ; the former are in possession of true roots, 
whose anatomical construction is much like that of the stem ; on the other 
hand, the latter family has no true roots, but as a substitute has subterranean 
shoots. The genus Isoetes , which is at present the only representative of 
[Annals of Botany, Vol. XXXIV. No. CXXXVI. October, 1920.] 
