L. Selago Linn.
This species is common in Europe, and is well known from the investigations of H Bruchmann (6) and C. E. Jones (13) and others, so that it will need but slight notice in this paper. It occurs commonly throughout the South Island of New Zealand in damp places as a member of fell-field, herb-field, and sometimes subalpine Nothofagus forest, and elsewhere on the high mountains.
L. Billardieri Spring.
This species is found in the forest throughout New Zealand. Though typically an epiphyte, growing pendulous from tree-fern trunks and the upper branches of forest-trees, it also not uncommonly grows on the ground. In North Auckland it is met with on peaty soil in groves of Leptospermum. On the volcanic islet of Rangitoto, Auckland Harbour, it grows on patches of humus among the blocks of scoria. In Southland and Stewart Island it occurs frequently on the damp forest-floor on patches of humus at the base of large tiees. In one instance I found a single “seedling” plant growing on a bush-road clay-cutting. The individual plant consists of a main stem, which in its short underground region is sparingly branched. This underground portion is covered with scale leaves, and bears a number of roots at its lower end. These [ unclear: ] oots are much branched, and are covered in their terminal portions with a mat of rhizoids. At or near the surface of the soil the stem branches dichotomously several times to form a tuft of aerial stems. When the plant is epiphytic these aerial stems hang in tresses from 1 ft to 4 ft. in length (see Cockayne, L, Fig 6, in “Report on a Botanical Survey of the Waipoua Kauri Forest,” 1908), when terrestrial the plant is more or less upright, and in some instances it is then hardly to be separated from L varium Several plants generally grow together, their subterranean portions thickly interpenetrating the patch of humus. The appearance of the plant, with its dichotomously branched aerral stems and numerous long terminal tetragonal fertile spikes, is well illustrated by Pritzel's figure of L Phlegmaria in Engler and Prantl (9).
L. varium R. Br.
This plant is stated by Cheeseman (7) to be probably only an extreme form of L Billardieri. It is sometimes epiphytic, but it occurs in those parts of New Zealand subject to a semi-subantarctic climate, and on Stewart Island and the Subantarctic Islands of New Zealand more commonly as an erect, stout, rigid terrestrial plant. On Stewart Island I found it growing on the forest-floor in large patches, some of which were as much as 12 ft. across.
L. Drummondii Spring.
There is only one locality, so far as is known, where this species occurs—viz., the Sphagnum bog at the east end of the small Lake Tongonge, at Kaitaia, North Auckland. I desire to thank Messrs. H. Carse and R. H. Matthews, of that neighbourhood, for kindly conducting me to the spot in January, 1914. In a recent letter the former states that the lake and bog are to be drained, so that probably this species, so rare in New Zealand, will disappear. The main stem of the plant is never more than 6 in. in length, and is generally branched several times. It creeps above ground, but is tightly bound down to the mossy surface by the adventitious roots, one of which is borne at the junction of each branch with the main stem. The cones are borne singly on erect peduncles, and stand from 2 in. to 4 in. in height. In several instances a fertile region was seen to be divided into two lengths by the interposition of a short sterile region, and in other cases the old cone of the previous year was observed to have grown on to form the new one.
L. laterale R. Br.
I have studied this species more especially on the clay “gum-land” in boggy localities around Kaitaia and on the Auckland Isthmus. In the latter locality it occurs at the margins of the small bogs which occupy the numerous hollows among the clay hills, growing amongst certain Cyperaceae and Gleichenia dicarpa var hecistophylla. Around Kaitaia and on the Peria Gumfields it grows extremely abundantly on the open damp hillsides. The surface soil of these gum-lands consists of a peaty humus, which for the greater part of the year holds much water, but which during the summer months is generally more or less dry. The adult plant consists of an irregular and much-branched colourless rhizome, which ramifies through the soil in all directions. The shorter branches emerge at the surface to form the e [ unclear: ] ect aerial shoots. These latter, when growing amongst thick scrubby vegetation, are extremely slender, and attain a height of from 2 ft. to 3 ft. On open ground they are short and stout, and often reddish in colour. The cones are short, and are normally lateral and sessile. In some cases, however, individual cones are borne on short leaf-covered peduncles, and they must then be regarded as terminal. Pritzel's description of this species in Engler and Prantl is rather misleading. He there states that the Cernua section comprises forms without a widely creeping main axis, mostly like a little tree. It is to be noted that it is only the aerial branches which are tree-like in the two New Zealand species L. laterale and L. cernuum. The main body of the plant in L laterale is subterranean and widely ramifying.
L. cernuum Linn.
This species is well known from the writings of Treub and of Jones (13). It grows very abundantly throughout the northern part of the North Island of New Zealand on clay moorlands as described for the preceding species. It thrives especially in North Auckland amongst scrub vegetation of the Gleichenia-Leptospermum association, individual plants often attaining to a length of 12–15 ft., and the upright branches to a height of 1–4 ft. It is also extremely common on the Volcanic Plateau, in the neighbourhood of hot water and near fumaroles. The
main stem of the adult plant is above ground, and has a serpentine habit of growth. It extends in a succession of loops and nodes, at each node the stem being fastened to the ground by a group of adventitious roots, which arise in the first place immediately behind the stem-apex on its ventral side, while from the loops arise the branches of limited and unlimited growth. The branches are borne laterally right and left on the main stem, but the erect tree-like fertile branches take their origin from its dorsal side. Here, again, Pritzel's description is misleading: only certain of the branches—namely, the fertile ones—are tree-like; the main body of the plant is widely creeping and branched. The figure which he gives in Engler and Prantl illustrating this species is that of an erect fertile branch only; the group of roots at the base should not be so figured. There are numerous short cones borne at the ends of the branchlets in the fertile regions.
L. densum Labill.
This species grows abundantly throughout the Auckland Province on clay land amongst light open “scrub” vegetation, and also in the more open parts of kauri forest near its outskirts. (For general habit see Cockayne, L., loc. cit., Fig. 16.). The main rhizome, which is from 4 ft. to 10 ft in length, is stout, and there are also subterranean branches both of limited and also unlimited growth, borne laterally on the main stem. The branches of limited growth emerge from the ground as rigid, erect, much-branched, tree-like, aerial shoots, generally from 1 ft. to 3 ft in height. I have often observed that when the plants are growing amongst tangled scrub the aerial shoots may be as much as 8 ft or 9 ft. in height, and in some cases remain totally unbranched. Stout adventitious roots arise ventrally from the main rhizome and branches, and are borne singly, generally immediately behind a point of branching. There are three distinct varieties of this species, corresponding to differences in the general size of the leaves with which the aerial branches are covered. The numerous short cylindrical cones are solitary and terminal on the ultimate branchlets. In the particular variety which is characterized by the acicular form of its leaves the branchlets on which the cones are borne are more or less modified as peduncles.
L. volubile Forst.
This species is common throughout New Zealand, excepting in the driest districts, growing freely amongst Leptospermum and other heath-like vegetation. It has a scrambling habit, or at times is a winding liane, spreading over the ground or over low-growing bushes Individual plants are often so much as 12–15 ft in length. There is a main axis of growth, on which are borne laterally, in the plane of the surface on which the plant is growing, branches of limited and also of unlimited growth. The leaves are dimorphous, as has been noticed and commented upon by Boodle (1), the larger laterally borne, sickle-shaped, and distichously spreading, the smaller linear, scale-like, and borne dorsally and ventrally. The distichous character is for the most part confined to the smaller branchlets on the branches of limited growth An account of the development of heterophylly in this species and in L. scariosum has been given in a former paper by the writer (11, p. 366). Here it need only be mentioned, as Goebel has already pointed out, that certain leaves on the main shoots are hook-like,
and so probably climbing-organs (10, p. 346). Adventitious roots are borne ventrally at intervals along the main axis. In places where the plants are scrambling over low-growing bushes these roots may attain a length of 3–5 ft. before reaching the ground. In the late winter and early spring a very characteristic feature is the thick envelope of mucilage which covers from 3 in. to 12 in. of the growing root-tip before it has reached the ground. The fertile spikes are thin and cylindrical, and from 1 in. to 4 in. in length, and occur in large terminal much-branched panicles. They are figured in Engler and Prantl (9). The fertile branches are to be found for the most part in those regions of the plant which are elevated on some low-growing vegetation, and they are thus generally pendulous. Although the panicles of spikes in their normal form are very distinct from the ordinary vegetative branches, yet close observation shows that all stages of transition may occur. Isolated sporangia are sometimes to be found on sterile branches; in other cases fertile and sterile branchlets are indiscriminately mixed; while in others, again, sterile tracts may appear in the spikes themselves.
L. ramulosum T. Kirk.
I have gathered this species from the peaty flats at the head of the Rakiahua Arm of Paterson Inlet, Stewart Island, and from bogs in the neighbourhood of Hokitika and Kumara, Westland. It occurs abundantly, covering the ground with mats of interlacing plants. It is common in such a habitat all over Stewart Island, ascending to the summits of the mountains; and is found also in bogs, both lowland and subalpine, throughout Westland and north-west Nelson. The individual plant is very short—from 2 in. to 9 in. in total length—and is irregularly branched both above and below ground. The study of this species as growing in Stewart Island shows that the subterranean portions are of two distinct kinds. Those stems nearer the surface are whitish in appearance, and are thickly covered with scale leaves; from these the aerial branches arise. Those portions which penetrate the peaty humus more deeply are brownish in colour, and are more or less naked of scale leaves, and are the ones which more frequently bear the adventitious roots. The two kinds of stem arise from one another without transitions. The aerial branches are procumbent or ascending, and are much branched. The short solitary cones are borne terminally on erect branches, but occasionally they may occupy a lateral position.
L. fastigiatum R. Br.
This species is common on open mountainous country throughout the South Island, especially on tussock grassland. It also occurs in subalpine Nothofagus cliffortioides forest, where it assumes a more mesophytic habit. In Southland and Stewart Island it also descends to low levels. There is a subterranean creeping main axis, which is usually from 1 ft. to 3 ft. in length, but which may be as much as 5 ft. long. Branches of limited and also of unlimited growth arise from the main axis, the former emerging from the surface to form the erect greenish or reddish tree-like aerial branches. These latter are from 6 in. to 12 in. in height, and are densely branched, but when growing amongst thick tussock-grass are much more slender in habit, and are taller. When growing on sour peaty soil the branches may be flattened to the ground. The cones are from 1 in. to 2 in. in length, and are borne, usually singly but sometimes two or more together, at the end of the branchlets on distinct peduncles.
L. scariosum Forst.
This species, like the last, occurs fairly commonly in open situations at fairly high elevations, especially throughout the South Island. In such a situation it is always creeping on the surface of the ground. Individual plants may have an extreme length of 5–6 ft., but are generally shorte [ unclear: ] . The stout and rigid main stem bears branches both of unlimited and of limited growth. The former are closely adpressed to the surface of the ground. and bear the adventitious roots. The branches of limited growth are heterophyllous, and are markedly flattened in the plane of the ground. The development of the heterophylly is different in this species from that in L. volubile, and has been fully described else-where (11, p. 366). The cones are from. 1 in. to 2 in. in length, and are borne singly at the ends of branchlets on peduncles, in the same manner as has been described for L fastigiatum, and as is so well known in the European species L clavatum. When growing amongst thick fern vegetation—as, for example, on the tailing-heaps in the neighbourhood of the old alluvial gold-mining claims in Westland—it is noticeable that this species may show an almost entire absence of the usual dorsiventral appearance of its branches. The lateral branches are erect, and, except in the older parts of the branches, the leaves are scattered and tend to be acicular in form, while in the ultimate branchlets they are reduced to mere scales. The general habit of the plants in these cases is almost scrambling, and the long, rigidly erect, naked, and closely crowded ultimate branchlets present a very characterstic and forest-like appearance. The tips of certain of these branchlets become fertile and develop as cones, while isolated fertile regions may also be found occasionally on other branchlets.