THE 
HEW PtfYTOIiOGIST. 
Vol. XII, No. 
March, 1913. 
[Published April 15th, 1913]. 
A BRITISH FOSSIL SELAGINELLA. 
By A. C. Seward, F.R.S. 
[With Plate IV]. 
riiHE fact that the genus Selaginella is now represented by a 
single species in the British Flora adds interest to the dis¬ 
covery of a Wealden species differing in habit from the recent type. 
Palaeobotanical literature contains numerous records of herbaceous 
Lycopods, referred to Lycopodites, Selaginites, Lycopodium, or 
Selaginella, but it is only in a very few cases that the untrust¬ 
worthy eivdence supplied by a superficial resemblance of the 
impressions in habit and leaf-form to recent species is confirmed 
by the discovery of spores. 1 It is almost impossible in many cases 
to distinguish fossil vegetative shoots of lycopodiaceous plants from 
those of certain Conifers and Bryophytes or even from some types 
of Dicotyledons, In the absence of sporangia or spores or of clear 
evidence of dimorphic foliage the identification of small fossil 
impressions as species of Lycopodites or Selaginites seldom rests on 
a satisfactory basis. 
The old generic name Selaginites has frequently been applied 
to fossils which afford no evidence of a closer relationship to 
Selaginella than to Lycopodium. In order to avoid the danger of a 
suggestio falsi associated with the use of a name clearly implying 
affinity to the recent genus, Zeiller 2 instituted the designation 
Selaginellites for fossil herbaceous lycopods which possess two kinds 
of spores, Brongniart’s genus Lycopodites being conveniently 
retained for isosporous types or for such sterile specimens as may 
with reasonable certainty be regarded as generically identified either 
with Lycopodium or Selaginella. Although the great majority of 
existing Selaginellas differ from Lycopodium in the possession of two 
sizes of foliage leaves, there are some members of the former genus, 
e.g., the British species S. spinosa, which bear leaves of one type only. 
1 For a general account of fossil herbaceous lycopods, see Seward (10), 
pp. 73-91. 
2 Zeiller (06), p. 140. 
