PRICKLY CLUB-MOSS. 127 



Prickly Club-moss (Selagindla selaginoides). 



Though several exotic Selaginellas are commonly cultivated 

 in our greenhouses, this is the only member of the genus that 

 is indigenous to Britain. It was long regarded as a species 

 of Lycopodium, from which genus, however, the Selaginellas 

 differ in the production of large and small capsules, contain- 

 ing respectively large spores (megaspores) and small spores 

 (microstores), which differ in their structure and in their 

 manifestations of vitality (Plate 130). When the coats of the 

 megaspore are ruptured, the contents are discovered to have 

 already developed into a colourless prothallium bearing several 

 archegones. When the microspore opens, instead of revealing 

 a prothallium, the contents are seen to escape in the form of 

 antherozoids which, by the lashing of a pair of cilia, make their 

 way to one of the archegones and fertilize it. 



The stem of the Prickly Club-moss is very slender, six inches 

 or less in length, and it creeps along the ground. The leaves 

 are small, lance-shaped, and toothed, rather loose in arrange- 

 ment, but attached all around the stem, and overlapping. They 

 are thin in texture, and a bright tender green in colour. The 

 stem is sparingly branched, the barren branches taking a 

 slightly upward direction ; but the fertile branches grow erect 

 and are terminated by stalkless cones. The scales of the cones 

 are similar in shape to the leaves, but longer, broader, and with 

 longer marginal teeth. The capsules are produced on the inner 

 faces of the scales of the cone, and they will be found mature 

 in July and August. (Plate 139.) 



The plant grows in boggy and marshy places, especially when 

 these are on mountain sides. It is a northern species its 

 range in this country extending from Shetland only as far south 

 as Wales, Cheshire, Derbyshire, and Lincolnshire. It is also 

 found in Ireland. In the Scottish Highlands it ascends to over 



