THE LYCOPODS (CLUBMOSSES) 



intervals. It occurs characteristically on mountains above the tree line. L. inundatum L. 

 is probably the most difficult species to detect, since the length of its stem is to be 

 measured in inches and not feet, although its leaves and solitary cone are in themselves 

 as large as in the others. It is scattered over the country at various altitudes but always 

 in boggy places and often in quite small colonies. 



L. Selago L. completes the list. This very conspicuous little plant, with the habit of an 

 erect dwarf bush covered with spreading spiny leaves, is the most easily found of all our 

 British species at an appropriate altitude, which is usually slightly lower than that 

 required by L. alpinum. It differs from all the others in ways which appear to be 

 morphologically primitive. The radially symmetrical erect stem and the absence of 

 specialized cones are two of the more important points, and in these respects its nearest 

 relatives among living species are to be found in the tropics, e.g. L. squarrosum; though if 

 fossils are also related, a point which must not be too readily assumed, L. Selago seems to 

 show more features of (perhaps superficial) resemblance to very ancient types such as 

 Drepanophycus (Devonian) or Baragwanathia (Silurian) than do any of the other species 

 listed. The interest of the relatively primitive construction in Lycopodium Selago is 

 somewhat enhanced by a geographical distribution which, at present, is virtually 

 worldwide, and by an abundance of individuals which is made possible by a very 

 characteristic vegetative reproductive mechanism. Detachable bulbils are borne in 

 place of some of the leaves on zones of the stem, alternating with zones in which the 

 leaves bear axillary sporangia, and these bulbils germinate very readily to produce new 

 plants. 



The sexual generation of the genus Lycopodium was for long a matter of speculation, 

 for it is exceedingly difficult to detect in nature, and the spores, though produced in 

 such abundance as to be sold commercially as 'Lycopodium powder', will only germinate 

 under very special conditions and even then only after a lapse of several years. The early 

 germination stages of L. inundatum were, however, seen in 1858 by de Bary, and adult 

 prothalli of the same species were found wild in 1887 by Goebel in Germany. Prothalli 

 and young plants of L. annotinum were found in Switzerland by Fankhauser in 1873 ^^*^ 

 again in Germany by Bruchmann in 1884, after which this last indefatigable and gifted 

 observer proceeded to discover the prothalli of all the other European species (Bruch- 

 mann, 1898) and at a later stage germinated their spores (Bruchmann, 1910). All these 

 specimens were of continental origin and most of them were from the Thuringerwald 

 and the Harz Mountains where, to quote Bruchmann, they are not so much rare as very 

 local in their occurrence. Prothalli have, however, also been seen in Great Britain by 

 W. H. Lang, who discovered those of L. clavatum in Scotland in 1899 and of L. Selago on 

 two occasions subsequently (Lang, personal communication). I am indebted to Pro- 

 fessor Lang for permission to reproduce an old photograph taken at the time of the dis- 

 covery of the prothalli and young plants of L. clavatum (Fig. 242) which will serve to 

 illustrate the type of structure. The gametophytes are colourless subterranean organ- 

 isms living saprophytically with the aid of an endophytic fungus as in Psilotum (see pre- 

 vious chapter), but with a characteristic shape which differs considerably from those of 

 that genus. There is therefore no risk of confusion with other organisms even if the 

 identity were not attested by the presence of young sporophytes. In practice, however, 



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