HoLLOWAY. — Sfi/f/irs in the New Zealand Species of Lycopodiuni. 193 



L. fastigiafum varies very much in the form of its aerial branches in 

 accordance with the environment. Plate XIV, A and B, represent two 

 extreme forms, the latter from Browning Pass at a height of 5,000 ft. and 

 the former from Westland at practically sea-level. The form lettered B 

 represents a portion of a plant as it grows commonly on the hard dense 

 cushions of Phi/llachne clavigera. The main rhizome is deeply buried in the 

 rotting substratum of the cushion, and the lateral branches are also rooted 

 and buried, but at a lesser depth. Arising from the lateral branches are 

 the short tufted foliage shoots, which appear as little compact rosettes 

 firmly resting upon the surface of the cushion. The cones are numerous, 

 and stand erect on very short pedicels to a height of j in. to ^ in. The 

 plant figured is sterile. This is an extreme xerophytic form, and is in marked 

 contrast to that lettered A, which represents the species as it occurs typically 

 around the alluvial goldfields in the very wet climate of the lowlands of 

 Westland. In these localities the aerial branches attain a height of 1 ft. 

 to 3 ft., and are often of a striking red or golden colour, handsomely 

 branched, with a terminal bunch of long, club-like cones. On the Canter- 

 bury mountains, where this species occurs abundantly, I have often 

 observed that when the plants are growing in a tussock-clump or amidst 

 other sheltering vegetation the aerial branches are tall and slender and 

 open-leaved, whereas those, perhaps of the same plant, growing in the 

 open in the full light of the sun only a foot or two away are short, sturdy, 

 and compact, with much thicker stems and closely imbricating leaves. 

 This species occurs also commonly in subalpine Nothofagus clijfortioides 

 forest, and there its habit is characteristically mesophytic. There is a 

 certain range of variability in the form of the strobilus and its pedicel, even 

 in individuals from the same locality. On some branches the tips of prac- 

 tically all of the ultimate twigs are fertile and there is no pedicel, there 

 being a gradual transition from the vegetative leaves of the twig to the 

 sporophylls. On other branches, again, the main axes of the branch are 

 continued on as long scantily-leaved pedicels, bearing one or more long, 

 club-shaped cones, which are often branched. The former condition is, 

 generally speaking, characteristic of the xerophytic type of branch, and the 

 latter of the mesophytic, although this distinction is not always kept. 

 Among the mesophytic form of plants some very extreme examples of 

 pedicel-formation are sometimes to be met with. 



As in the case of the last-named species, the wet climate of the low- 

 lands of Westland encourages a luxuriant growth of L. scariosum. Plate XII, 

 fig. 2, B, shows a portion of the rhizome of this species with two small 

 erect lateral branches bearing cones. The development of heterophyUy in 

 this species, as in the case of L. voluhile, has been elsewhere described by 

 the writer (15, p. 366). In L. voluhile the acicular leaves are finer in form 

 than in the other species, and there are about twice as many orthostichies. 

 HeterophyUy in L. voluhile arises through two orthostichies on each lateral 

 face of the branch approximating to one by being flattened in the plane of 

 the ground, the leaves of these orthostichies assuming the larger form. At 

 the same time the leaves of the two or three orthostichies placed ventrally 

 and also dorsally become much reduced. All stages in the development of 

 this dimorphism can be seen in young plants, and also in the reversion 

 foliage which has already been noted as occurring in this species. In the 

 case of L. scariosum it is the leaves of the two dorsally placed orthostichies 

 which become flattened in the plane of the ground and assume the larger 

 form, there being two to four orthostichies of much reduced scale-like leaves 

 7 — ^Trans. 



