Mosses together with the liverworts form a very natural and usually distinct group, the Bryophytes. The mosses, especially, can usually be placed as such in the field and are easily collected, requiring only drying and packeting, as they moisten out well for later examination. Their main drawback is their small size, some being only a millimetre or two high, even when in fruit, so that a microscope is required for their examination, as also for the minute structure of leaves and peristomes of the larger species, some of which reach the unusual size for mosses of 1 ½ feet or more.

Mosses are widely spread in New Zealand, ranging from mountain rocks to coastal sands. We have our share, too, of very interesting species, and a high endemism, given as nearly 40 per cent, by Martin, but, of course, there is the usual cosmopolitan element.

Some of our mosses were included in Dr. W. J. Hooker's “Musci Exotici,” published in 1818-1820, and in 1847-1859 Sir J. D. Hooker published further figures and descriptions in his Flora Antarctica, Flora Novae-Zelandiae and Flora Tasmaniae. In 1867 he credited us with 350 species in the “Handbook”. These had been worked up by Hooker himself, by Dr. Taylor and Wm. Mitten. Mosses have a wide appeal and while Hooker and Colenso had collected many of the above mosses, many others had sent in collections, including Cunningham, Lyall, Sinclair, Menzies, Knight and Hector and Buchanan.

Various collections were made after this, notably by T.W.N. Beckett; by Robert Brown of Christchurch; and by S. Berggren of Sweden. Beckett and Brown published many papers in the Transactions of the N.Z. Institute from 1882, to 1908. These and other papers were collected by Brotherus in the moss section of Engler and Prantl's “Pflanzenfamilien” published in 1924.

H. N. Dixon, however, laid the foundation for an up to date Manual of our mosses with his “Studies in the Bryology of New Zealand” which was published in six parts, 1913-1929, by the N.Z. Institute as Bulletin No. 3. In this Dixon collected and critically examined all records of our mosses and brought the nomenclature up to date. He credited us with under 500 mosses, grouped into about 170 genera. This work revived interest in the mosses and a small keen band of collectors has since carried out extensive field work which it is hoped will make the compilation of a manual possible.

At present no such recent work exists but students will find the following works useful:

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Dixon's work mentioned above, which has six plates and mentions all the mosses then known to grow in New Zealand, but, while discussing critical species in detail, it often gives no description of the well known species. Dixon's “Student's Handbook of British Mosses,” 1924, is an excellent book so far as it deals with our genera. W. Martin published a check list of our mosses with much other information in Volume 76 (1946) of the Transactions of the Royal Society and also a good popular account of our mosses with several plates in his “Flora of New Zealand” (3rd edition).

Mosses are divided into three sub-classes, based on the structure and development of the capsule: (i) Sphagnales (ii) Andreaeales and (iii) Bryales, the first two containing only one genus each. The Bryales are divided up into two clans, based on peristome characteristics: the Nematodonteae have solid teeth, not tranversely barred, derived from several concentric layers of the cells of the Sporogonium and include seven families: the Arthrodonteae have the teeth (sometimes absent) thin and membranous, derived from a single layer of cells of the sporogonium, and are transversely barred and articulate and include the rest of the mosses—some 67 families. These latter are again divided up into 3 Sub-clans on peristome characteristics, so that it can be seen what an important part the capsule plays in the classification of mosses and it should be collected whenever possible. The Sub-clans are divided into orders, families and genera on characters taken from the gametophyte as well as from the sporophyte.

The main divisions of mosses can be told as follows:

Sphagnales: White or whitish green mosses with fascicled or whorled branches, growing in bogs or wet ground. Leaves of very narrow long cells which anastomose to form a network of large wide thin-walled cells which are often strengthened with evident spiral thickenings: operculum falling: no peristome (Figs. 17, 18) Sphagnum.

Andreaeales: Small reddish to dark purple or black mosses usually growing on alpine rocks, very occasionally larger and growing in mountain streams. Leaves inserted all round the stem, cells dot like. Capsule black, erect, dehiscing by 4 lateral slits, the operculum never being shed. Andreaea.

Bryales: The operculum is usually shed, though in exceptional cases this is not so and then the capsule wall rots or breaks irregularily (not by regular slits) to release the spores. Includes all the other mosses.

Miss Adams' contribution in supplying the drawings is gratefully acknowledged.

The Key below gives characteristics for 123 of the Commonest Genera of New Zealand Mosses out of the total of about 170.

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Key to the Genera of Mosses

page 134 page 135 page 136 page 137 page 138 page 139 page 140 page 141 page 142

Glossary.

• Acuminate: tapering to a gradually diminishing point: more drawn out than “acute”.
• archegonium: the female sexual organ which after fertilization develops into the sporophyte.
• alar cells: a usually conspicuous group of cells at the outside base of a leaf differing greatly in size or wall thickness from the surrounding cells, (Fig. 7).
• apiculus: a short abrupt point to a leaf usually but not always acute (Fig. 14).
• apophysis: the swelling sometimes present at the union of the capsule and seta.
• calyptra: the upper part of the ruptured archegonium, which is carried up by the capsule as it develops and forms a covering for it, (Fig. 45).
• campanulate: more or less bell shaped with entire base.
• cernuous: nodding.
• ciliate: having the margin fringed with hairs, (Fig. 11).
• clavate: club shaped, broadest about the middle.
• cleistocarpous: of a capsule from which the operculum does not separate.
• cochleariform: spoon shaped, i.e., strongly concave with obtuse apex.
• complanate: flat or plane: of leaves or stems.
• conic: cone shaped, circular in cross section: height only once or twice the diameter of the base.
• cordate: heart shaped.
• corticolous: living on bark.
• crenulate: margin provided with small rounded notches.
• cuculiate: of a calyptra split up on one side, (Fig/. 45).
• dehiscence: the manner in which a capsule opens to scatter its spores.
• discoid: of a male flower, disc like with a broad flat top.
• distichous: arranged in two vertical rows, (Fig. 32).
• dorsal: the upper face or surface: cf. ventral.
• emergent: a capsule wholly included in the perichaetial leaves is termed “immersed” (Fig. 36): if the capsule is partly above them, it is “emergent”: the perichaetial leaves do not reach the base of the capsule, it is “exserted”.
• excurrent: of a nerve, extending beyond the leaf apex as an extension or awn, (Fig. 5).
• exserted: see “emergent”.
• falcate: sickle shaped: curved like a scythe blade.
• fascicled: arranged in a small bundle or close cluster.
• fibrillose: furnished with fine fibres or threads.
• gametophyte: in mosses, the leafy plant, which bears the leaves and sexual organs; page 143 an archegonium develops into the capsule and seta, the sporophyte, which is parasitic on the gametophyte.
• gemmae: outgrowths on stems or leaves of few or many cells which are shed to reproduce the plant vegetatively, (Figs 10, 43).
• gemmiform: of a male flower; shaped like a small bud, ovoid with a narrow top.
• hyaline: translucent: colourless, (Fig. 18).
• immersed: see emergent, (see fig. 36).
• lamellate: furnished with lamellae or thin plates of tissue at right angles to the face bearing them, (Figs. 1, 9).
• lanceolate: shaped like a lance-head: broadest near the base, tapering upwards from a narrow ovate base.
• linear: narrow and elongated with parallel margins.
• mitriform: of a calyptra, campanulate, not split up one side as in a cucullate calyptra, (Fig. 46).
• obovate: inversely ovate, with the broadest part near the apex.
• operculum: the lide of the capsule, which usually is shed so that the spores can be scattered, (Figs. 22, 25, 27, 28).
• ovate: shaped like the longitudinal section of an egg with the broadest part near the base.
• papilla: a small superficial elevation.
• papillose: provided with papillae, (Fig. 2).
• percurrent: of a nerve, hardly reaching the apex of a leaf.
• perichaetial: of leaves (Fig. 42), those at the base of the seta (Fig. 32), which often differ from the others.
• peristome: the teeth which form a single or double row of appendages to the capsule mouth, seen on the fall of the operculum: sometimes absent, when the capsule if “gymnostomous”.
• piliferous: bearing long hair-like points, (Figs. 5, 12).
• pilose: furnished with rather long and soft distinct hairs.
• pinnate: “feather-like” with more or less regular lateral branching, (Figs. 40, 41).
• plicate: furnished with “plicae” or folds like those of a fan, (Fig. 14).
• p.p. (pro parte) in part: indicates that another section of the genus appears in another part of the key.
• protonema: the branched thread like growth arising from the germinated spore which gives rise to the moss plant, (Fig. 31, b).
• pyriform: pear-shaped.
• rostrate: beaked with a long slender point.
• secund: turned or pointing to one side only.
• serrate: furnished with saw like teeth.
• serrulate: minutely serrate.
• sessile: without a stalk.
• seta: (a) a bristle, (b) the capsule stalk, (Fig. 32).
• setaceous: bristle like.
• setose: sparsely provided with bristles.
• spathulate: rounded or shortly oblong with the lower end narrow and drawn out: like a druggist's spatula, (Fig. 4).
• sporophyte: see gaemtophyte.
• squarrose: with points spreading widely, giving a rough appearance to the plant.
• stegocarpous: of a capsule, with the operculum falling normally.
• stipes: the lower simple erect stem of a branched moss.
• subula: the longer narrowed part of narrow leaf: the broader basal part is the “lamina”.
• subulate: awl shaped.
• terete: round, not angled or grooved.
• tomentum: a densely matted woolly covering.
• turbinate: top shaped.
• vaginant: sheathing, as the base of an iris leaf, (Fig. 8).
• ventral: the undersurface or face: cf. “dorsal”.

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Key to Plates

1.	Transverse section of leaf of Polytrichum commune showing lamellae on the upper surface.
2.	Leaf of Dicnemoloma showing papillose lower surface.
3.	Leaf of Leptobryum pyriforme.
4.	Leaf of Pterigophyllum dentatum with forked nerve and denticulate margin.
5.	Leaf of Tortula princeps showing the nerve excurrent in a long dentate, flexuose, piliferous point.
6.	Leaf of Hypnum cupressiforme, strongly curved and nerveless.
7.	Leaf of Acrocladium auriculatum with short nerve and conspicuous alar areas.
8.	Leaf of Fissidens leptocladus showing the nerve reaching the apex, vaginant leaf base (stippled) and thickened margins.
9.	Leaf of Polytrichum commune showing dentate margins and upper surface opaque owing to the numerous longitudinal lamellae.
10.	Leaf of Calyptopogon mniodes showing the apical mass of gemmae on the upper surface.
11.	Leaf of Catharomnion ciliatum showing the remarkable ciliation.
12.	Leaf of Hymenodon piliferus showing piliferous apex and nerve not reaching the apex.
13.	Leaf of Rhizogonium mnioides with thickened, dentate margins.
14.	Leaf of Cladomnion ericoides, nerveless, plicate and with recurved apiculus.
15.	Leaf of Ctenidium pubescens showing the margins dentate almost to the base.
16.	Leaf of Dicranoloma dicarpum with strongly spinulose upper margins.
17.	Branch leaf of Sphagnum cuspidatum.
18.	Sphagnum: part of a branch leaf surface, strongly magnified to show the long chlorophyllose cells enclosing the larger hyaline ones which are strengthened with “spirals” or cell wall thickenings.
19.	Capsule of Polytrichum juniperinum and front view of its mouth showing the (ruptured) circular membrane held in place by the 64 short teeth.
20.	Capsule of Tortula princeps, erect, with twisted peristome rising from the entire basal part.
21.	Capsule of Ceratodon purpureus, inclined and ribbed.
22.	Capsule of Bryum truncorum, pendulous with conical operculum.
23.	Capsule of Weisia viridula, erect, with short peristome teeth.
24.	Capsule of Conostomum pusillum, striate and horizontal.
25.	Capsule of Polytrichadelphus magellanicus with operculum.
26.	Capsule of Trematodon suberectus, inclined with long neck.
27.	Capsule of Hypnum cupressiforme, inclined and with conicomamillate operculum.
28.	Capsule of Ptychomnion aciculare, inclined and striate with the strikinly long operculum.
29.	Capsule of Leptobryum pyriforme.
30.	Capsule of Orthotrichum hortense, erect and ribbed with short, recurved outer peristome. The inner peristome consists of 8 filiform processes which remain more or less horizontal across the mouth, but may be soon lost.

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Key To Plates

31.	(a) Archephemeropsis trentepohlioides, part of tuft with young capsules and male flowers. (b) Enlarged piece showing male flowers.
32.	Fissidens leptocladus showing terminal seta.
33.	Cyathophorum bulbosum, ventral side, showing the three rows of leaves and capsules.
34.	Hypopterygium setigerum showing umbrella-like growth habit.
35.	Pterigophyllum dentatum showing leaves inserted in several rows but spreading laterally to form a flattened “frond”.
36.	Hedwigia albicans with immersed capsules.
37.	Leptobryum pyriforme.
38.	Macromitrium longipes.
39.	Physcomitrium conicum with gymnostomous capsule.
40.	Thuidium furfurosum with bi-pinnate branching.
41.	Weymouthia mollis showing irregular or sub-pinnate branching.
42.	Dicranoloma fasciatum showing the perichaetial leaves sheathing the whole seta.
43.	Tetraphidopsis pusillus showing terminal heads of gemmae.
44.	Hypnum cupressiforme with the densely placed curved leaves giving the stems a turgid appearance.
45.	Fringed cucullate calyptra of Campylopus torquatus.
46.	Entire mitriform calyptra of Cyathophorum bulbosum.