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The Vegetation of New Zealand

2. The Elements of the Flora

2. The Elements of the Flora.

The endemic element.

The endemic species of Pteridophyta, Gymnospermae and Angiospermae (monocotyledons 294, dicotyledons 1077) number 1451 and constitute 78.6 per cent of the vascular flora. Taking each group separately, 36 per cent of the pteridophytes are endemic, 67 per cent of the monocotyledons and 88 per cent of the gymnosperms (20) and dicotyledons taken together.

The endemic species are by no means all of one class but range from those extremely distinct from any other species either of the New Zealand page 404or any flora (e. g. Simplicia laxa, Hectorella caespitosa) to those almost identical with species of other regions (e. g. Carex Gaudichaudiana, Oxalis lactea)

There are 40 endemic genera which like the endemic species show strongly different degrees of endemism, but here for convenience they are arranged in their systematic sequence. The following is a list such genera together with a brief account of the affinities of each: — Loxsoma (Filices) distantly related to Loxsomopsis of Costarica and Ecuador. Simplicia (Gramin.) monotypic considered by Hackel intermediate between Sporobolus (tropical and subtropical especially in America but only introduced in New Zealand) and Agrostis (see Cheeseman 1906:861).

Desmoschoenus (Cyperac), a monotype agreeing — according to Hooker (1864:303) — with Isolepis in its floral characters, as A. Richard had shown, but transferred by Boeckeler in 1878 to Scirpus under Banks and Solander's unpublished name S. frondosus. Sporodanthus (Restionac), a monotype, is allied to the Australian Lepyrodia from which it differs in its 1-celled, 1-seeded fruit, but Bentham and Hooker, considering the 1-celled ovary due to abortion, placed the species in Lepyrodia. Cheeseman, on the contrary, found no trace of a 3-celled ovary in young buds, and considered von Mueller's genus, Sporodanthus, would be restored. Chrysoboctron (Liliac), with 3 species, and, at least, one well-marked variety of one of them, was established by Hooker in 1844 but in 1864 was transferred by him to Anthericum and, later, by Bentham and Hooker (Genera Plantarum) and Engler (Pflanzenfamilien) it was merged into Bulbinella, a South African genus. Pentalochiius (Orchid.), with 2 species, founded by R. S. Rogers in 1924, is related to Caladenia and "approaches very closely to Glossodia" — a small Australian genus. Mida (Santalac), with 2 species and many hybrids between them, is closely related to the Australian genus Santalum, and it would not be endemic but for the fact that the only other known species of the genus — M. fernandezianum (Phil.) Sprague et Summerh. — is extinct "the last known tree having died between 1908 and 1916" (Sprague, T. A. and Summerhayes, V. S., Kew Bull. Misc. Inform., No. 5, 1927:198). Tupeia (Loranthac), a distinct monotype related both to the Viscoideae and the Loranthoideae. Dactylanthus (Balanophor.), is a very distinct monotype, and according to Hooker "a most remarkable" genus. Hectorella (Caryophyll.), is a monotype of somewhat doubtful affinity possibly related to the Kerguelan Lyallia (see Ewart, Journ, Linn. Soc. 38:1–3.) but placed by Hooker and others in the Portulacaceae. Wintera (Winterac), with 3 species, has been removed from the closely-related Drimys by Hutchinson, the latter name to be applied to the other members of the family which range from Central and South America to eastern Australia, New Caledonia and the Malay Archipelago. W. R. B. Oliver (1925:3) considers the name Drimys should be applied to the New Zealand species and Wintera to the South American, and I presume the other species. Pachycladon (Crucif.), page 405a monotype, according to Hooker is intermediate between the Sisymbrieae and the Lepidineae, Notothlaspi (Crucif.), 2 species, is placed by Prantl in the Thelypodieae Stanleyinae next to Pringlea of Kerguelen Land. Ixerba (Saxifragac), monotypic, belongs to the section Escallonioideae and is nearest to Brexia of Madagascar and the Seychelles. Carpodetus (Saxifragac.), monotypic, also belongs to the Escallonioideae and is placed by Engler between the Australian-New Caledonian Argophyllum and the Lord Howe Island Colmeiroa. Corallospartiun (Legum.), 2 species, is closely related to the almost endemic Carmichaelia. Chordospartium (Legum.), monotypic, confined so far as known to two valleys of the North-eastern district, comes nearest to Corallospartium but also possesses characters of Carmichaelia and the following genus. Notospartium (Legum.), 2 species, differs from the above Leguminosae in its rather long, linear many-jointed pod and would be accorded generic rank by any systematist. Entelea (Tiliac), monotypic, is related to the South African Sparmannia. Hoheria (Malvac), at least 6 species, belongs to the Malvineae-Sidinae and is related to the indigenous and Australian Plagianthus and to Sida, a genus of wide range including Australia. Tetrapathaea (Passiflor.), monotypic, is by some united with Passiflora, from which it differs in its dioecious and tetramerous flowers. Stilboearpa (Araliac), 3 species (2 confined to the Subantarctic Province and 1 to the Stewart and Fiord districts), is somewhat closely allied to Aralia (Malayan, North American, east Asian and Australian). Anlsotome (Umbell.), 21 species, is closely related to almost endemic Aciphylla (2 Australian) and is frequently placed in Ligusticum from which it differs according to Cheeseman "in the narrower fruit with the ribs often unequal in height and in the fewer vittae". Coxella, monotypic and confined to the Chathams, has been referred to Aciphylla, Gingidium, Ligusticum and Angelica, with none of which does it properly agree. Corokia (Cornac), 3 species and a well-marked variety of one of them, is placed by Harms between the Himalayan-east Asian Helwingia and Cornus, a genus wide-spread in the Northern-Hemisphere. Myosotidium (Borrag.), monotypic, and confined to the Chatham Islands, is a distinct genus belonging to the Borraginoideae-Cynoglosseae, its nearest ally appearing to be Paracaryum of Central Asia and the Mediterranean. Teucridium (Verbenac), monotypic, is related but not closely to the Himalayan-African Holmskioldia. Pygmaea (Scroph.), 3 species, is related to Hebe but all are herbs of cushion-form, the leaves minute and not quadrifarious, the flowers solitary and terminal and the calyx 5–6-Iobed. Siphonidium (Scroph.), monotypic, is closely related to Euphrasia, a common genus in New Zealand, but amply distinct. Rhabdothamnus (Gesneriac), monotypic, forms with the New Caledonian Coronanthera and the Lord Howe Negria the small group Cyrtandroideae-Coronanthereae-Coronantherinae. Alseuosmia (Caprifoliac), number of species doubtful through overshadowing by their hybrids, is perhaps more closely page 406related to Lonicera than to any other genus but differing from all members of the Caprifoliaceae in its alternate leaves. Colensoa (Campanulas), monotypic, is very closely related to Pratia from which it differs in its tall erect habit, large leaves, racemose intlorescence, large flowers and large stigmatic lobes, but by Schokland it was united to this genus — a course followed by Gheeseman in Illustrations of the New Zealand Flora, 1914, but reversed in his Manual ed. 2, 1925. Oreostylidium (Stylidiac), monotypic, is related to the Australian Stylidium, in which it was placed by Hooker, but differs in its equal corolla-lobes, erect short column and indehiscent capsule. Pachystegia (Compos.), a monotype of which there are probably several varieties. for a long time kept in Olearia, differs from that genus in the great multibracteolate, ovoid involucre with the bracts in many series and the uniseriate pappus with the hairs equal and clavate. Shawia (Compos.), 2 species and many hybrids between them, is closely related to Olearia with which it is generally united but it differs in the head consisting of only 1 florest which is tubular and hermaphrodite. Pleurophyllum (Compos.), 8 species, is confined to the Subantarctic province and differs only from the almost endemic Celmisia in habit and its racemose inflorescence. Haastia (Compos.), 3 species and some varieties, is related to no indigenous genus and apparently comes nearest to the Madagascan Psiadia. Raoulia, 22 species, is related closely to Helichrysum and Gnaphalium and "is founded more upon habit1 than upon fully good and distinctive characters" (Cheeseman 1925: 968) and it embraces the two subgenera dealt with below. Leucogenes (Compos.). 2 species2, is more closely related to Psychrophyton than to any other of the Gnaiphaloid-Compositae. Brachyglottis (Compos.), 2 species, which are closely allied to the shrubby section of the genus Senecio. Traversia (Compos.), monotypic, is very closely relatad to Senecio and by Bentham and Hooker united to that genus, but it differs in the rigid pappus, coriaceous involucral scales, and leaf-venation, as Hooker pointed out, and is allied to the Juan Fernandez genera Balbisia and Robinsonia.

Endemism, usually of a weaker character, is shown in the following endemic divisions of 14 genera: — Deschampsia (Gramin.) excluding D. caespitosa, contains 6 species, which differ from all members of the genus proper in the awn being terminal, very small or wanting. According to page 407Cheeseman (1925:164) "they may ultimately form a separate genus". Luzula (Juncac.) contains 6 species distinguished by their low stature and cushionform. Buchenau in Das Pflanzenreich gives no name to this distinct group but a rather long diagnosis. Cordyline section Dracaenopsis (Liliac.) includes all the New Zealand species (4) of the genus. Knightia (Proteac.) consists of 3 species, the type, K. excelsa, being endemic but the other 2 form a sub-genus, Eucarpa which is confined to New Caledonia. Beilschmiedia (Laurac), about 40 tropical and Australian species, is represented in New Zealand by 2 species for which Hooker established the genus Nesodaphne. Acaena section Mierophyllae (Rosac.) is distinguished from other species of the genus by the small leaves arid spines — present or wanting — without barbs. Carmiehaelia (Legum.) but for C. exsul of Lord Howe Island would be endemic, but in lluttonella it has a small endemic subgenus distinguished by its indehiscent pod. Hoheria (Malvac), a distinct endemic genus is sharply divided into two subgenera, Euhoheria — the Hoheria of the Manual, 3 species or more, distinguished by the 5–7 carpels, the capitate stigma and the fruit conspicuously winged; and ApterocarpaGaya of the Manual, 3 species, distinguished by the 10–15 carpels and the fruit either inconspicuously winged or wingless. Epilobium (Onagrac.) possesses the endemic section, Dermatopliyllae, 12 species, which are supposed to be distinguished by the semi-woody stems, particularly woody at the base, the more or less rigid coriaceous leaves, and the few terminal flowers. The group is not well-marked and its limits badly defined. Fuchsia (Onagrac.) is represented by the subgenus Skinnera, 3 or 4 species, distinguished by the constriction at the base of the calyx. Stilbocarpa (Araliac), a most distinct endemic genus, falls into 2 well-marked subgenera — Stilbocarpa proper, 1 species, and Kirkophytum, 2 species — the former distinguished by its 3–4-celled ovary and fruit hollowed at the apex, and the latter by its 2-celled ovary and fruit not hollowed at the apex. Hebe (Scroph.) has 3 most distinct endemic groups not connected with any other of the numerous species, namely, the whipcord group (H. tetragona &c), the H. epaeridea group and the H. macrantha group. Olearia (Compos.) has the group distinct from all its other species which includes O. angustifolia and its 3 allies. Celmisia (Compos.) possesses the very distinct section, Jonopsis, which contains the subantarctic C. vernicosa and C. campbellensis. Raoulia (Compos.) is made up of the subgenera Eu-Raoulia and Psychrophyton, the former with 5–150 thin, slender pappus-hairs and the latter with 15–25 thickened towards the apex; in this group come the vegetable-sheep with 4 or more species. Cotula (Campos.) has 2 Chatham Islands' species — Cotula Featherstonii and C. Renwiekii — quite distinct from any other species of the genus.

The palaeozelandic element.

In considering the origin of the New Zealand flora, and indeed that of islands in general, the custom is to assume that the land was gradually peopled by plants from adjacent land-surfaces. page 408But in the case of New Zealand, since the present dry land dates from mesozoic times; and, that long before the angiosperms had appeared on any part of the earth, its area, then quite extensive, was occupied by similar plants to the world at large, then, if there be anything in evolution, we must conclude that there is no reason why certain genera, now more or less wide-spread, should not be of New Zealand origin. In other words, it seems right to consider that tertiary New Zealand possessed a flora part of which had originated on her own soil, and that there exists to-day an ancient New Zealand element just as there does an Australian, Malayan or South American. Such an element was assumed by Engler, and it formed a portion of his palaeoceanic element. To this assumed autochtonic tertiary element I suggested the name palaeozelandic. As to what genera should be included is entirely a matter of conjecture. Certainly, the fact of endemism, at the present time, does not stamp a genus as palaeozelandic any more than does the occurrence of a common New Zealand genus in Australia, Malaya or even South America debar it from being so considered. Thus Cheeseman (1909:466) is of opinion that Edwardsia tetraptera and Hebe elliptica migrated from New Zealand to South America and not vice versa, as is generally believed. To go a little further, it seems not unlikely that various New Zealand plants, e. g., — Chrysobactron, Stilbocarpa, Aciphylla, Gelmisia &c. are quite as much "Antarctic" as even Nothofagus and Donatia.

The following are possibly palaeozelandic:Dacrydium (6 N.Z., 4 New Cal., 1 Tas., 3 Mal.); Phyllocladus (3 N.Z., 1 Tas., 2 Mal), Carex-Echinochlaenae (14 N.Z., 2 Tas., 1 Juan Fernandez, 1 Chile); Deschamspia, the group already referred to under the last head (6 N.Z.); Astelia (12 N.Z, 1 east-Aus.-Tas., 4 Pol., 4 Subant. S. Amer.); Phormium (1 N.-Z., 2 N. Z.-Norf. Id.); Chrysboactron (3 N. Z.); Herpolirion 1 N. Z. east-Aus.-Tas.); Hectorella 1 N. Z.; the group referred by Cheeseman to Nasturtium but probably an undescribed genus (6 N. Z., 1 Tas., 1 N. Z.-Tas.), Pachycladon (1 N. Z.); Carmichaelia (25 N. Z., 1 Lord Howe), the allied genera are here considered late Tertiary; Aristotelia (2 N. Z., 1 Tas., 2 eas Aus.,-1 New Guinea, 1 New Heb., 1 or 2 Chile); Melicytus (4 N. Z., 1 N. Z.-Pol); Hymenanthera (6 N. Z., 1 Norf., 1 Aus.); Gunnera-Milligania (9 N. Z., 1 Tas.); Nothopanax (7 N. Z., 2 Aus., 1 New Cal., 1 Lord Howe); Pseudopanax (7 N. Z., 2 Subant. S. Amer.); Aciphylla (29 N. Z., 2 east Aus.); Anisotome (21 N. Z.); Coxella (1 N. Z.); Angelica, the endemic group, distinct from the genus in general, and hardly belonging there (5 N. Z.); Corokia (3 N. Z.); Dracophyllum (28 N. Z., 5 New Cal., 10 Aus. or Tas.); Myosotidium (1 N. Z.); Myosotis-Exarrhena (13 N. Z., 1 east Aus.-Tas.), Hebe (64 and more N. Z., 2 N. Z.-Subant. S. Amer., 2 Aus.-Tas.); Pygmaea (3 N. Z.); Siphonidium (1 N. Z.); Coprosma (48 N. Z., 22 in Aus., Pol., MaL and Juan Fernandez); Oreostylidium (1 N. Z.); Lagenophora (8 N. Z., 4 Aus., 2 Pol., 2 Subant S. Am.), Pleurophyllum (3 N. Z.), Cel- page 409misia (53 N. Z., 1 N. Z.-Aus.-Tas., 1 Aus.); Raoulia (22 N. Z.);Haastia(3 N. Z.); Abrotanella (9 N. Z., 2 Tas., 1 east Aus., 3 Subant. S. Amer., 1 Rodriguez Id.) and Leucogenes (2 N. Z.).

The Australian element.

Dealing first with the genera, the following 38 genera, or subdivisions of such, are confined to New Zealand and Australia, a few of which have, however been already classed as palaeo-zelandic: — Phylloglossum (Lycopod.) 1 N. 1 Z.-Aus.; Althenia (Potamoget.) 1 N. Z., 3 Aus.; Amphibromus (Gramin.) 1 N. Z., Aus.; Microlaena (Gramin.) 5 N. Z., 1 N. Z.-Aus., 2 Aus.; Echinopogon (Gramin.) 1 N. Z.-Aus.; Carex-Inversae (Cyperac.) 2 N. Z., 1 N. Z.,-Aus. 1 Aus.; Herpolirion (Liliac.) 1 N. Z.-Aus.); Rhipogonum (Liliac.) 1 N. Z., 4 Aus.; Orthoceras (Orchid.) 1) N. Z.-Aus.; Caleana (Orchid.) 1 N. Z.-Aus., 3 Aus.; Calochilus (Orchid.) 2) N. Z.-Aus., 1 Aus.; Chiloglottis (Orchid.) 1 N. Z., 1 N. Z.-Aus., 5 Aus.; Adenochilus (Orchid.) 1 N. Z, 1 Aus.; Townsonia (Orchid.) 1 N. Z., 1 Aus.; Persoonia (Proteac.) 1 N. Z, 60 or more Aus.; Poranthera (Euphorb.) 1 N. Z., 1 N. Z.-Aus., 4 Aus.; Rhagodia (Chenepod.) 1 N. Z.-Aus., 10 Aus; Drosera-Bryastrum (Droserac.) 1 N. Z.-Aus.; Quintinia (Saxifrag.) 2 N. Z., 3 Aus.; Ackama (Cunoniac.) 1 N. Z., 1 Aus,; Clianthus Legum.) 1 N. Z., 1 Aus.; Swainsona (Legum.) 1 N. Z., 30 or more Aus.; Phebalium (Rutac.) 1 N. Z., 34 Aus., Plagianthus (Malvac.) 2 N. Z., 9 Aus.; Gunnera-Milligania (Halorrhag.) 9 N. Z., 1 Aus.; Actinotus (Umbell.) 1 N. Z.-Aus., 9 Aus.; Aciphylla (Umbell.) 29 N. Z., 2 Aus.; Pernettya-Porandra (Ericac) 1 N. Z., 1 Aus.; Pentachondra (Epacrid.) 1 N. Z.-Aus., 4 Aus.; Archeria (Epacrid.) 1 N. Z., 4 Aus.; Logania (Loganiac.) 1 N. Z., 17 Aus.; Liparophyllum (Gentian.) 1 N. Z.-Aus. — subantarctic in character; Myosotis-Exarrhena (Borraginac.) 13 N. Z., 1 Aus.; Mentha-Eriodontes (Labiatae) 1 N. Z., remainder Aus.; Isotoma (Campan.) 1 N. Z.-Aus.; 7 Aus.; Celmisia (Compos.), 53 N. Z., 1 N. Z.-Aus., 1 Aus.; Ewartia (Compos.) 1 N. Z., 4 Aus.; Craspedia (Compos.) 4 at least N. Z., several Aus., but genus in confusion owing to hybrids and epharmones.

Almost in the same class as the last are those genera which extend to Norfolk or Lord Howe Islands or even New Caledonia, e. g. Dichelachne (Gramin.) 1 N. Z.-Aus., 1 N. Z.-Aus.-Norf.; Xeronema (Liliac.) 1 N. Z., 1 New Cal.; Arthropodium (Liliac.) 2 N. Z., 6 Aus., 1 New Cal.; Prasophyllum (Orchid.) 2 N. Z., 2 N. Z.-Aus., 26 Aus., 2 New Cal.; Pterostylis (Orchid.) UN. Z., 2 N. Z.-Aus., 2 New Cal., 34 Aus.; Acianthus (Orchid.) 1 N. Z., 4 Aus., 2 New Cal.; Lyperanthus (Orchid.) 1 N. Z., 4 Aus., 1 New Cal., Pennantia (Ioacinac.) 1 N. Z., 1 Aus., 1 Norf.; Pomaderris (Rhamnac.) 2 N. Z., 3 N. Z.-Aus., 17 Aus., 1 New Cal.; Hymenanthera (Violac.) 6 N. Z., 1 Norf., 1 Aus.; Dracophyllum (Epacrid.) 28 N. Z., 10 Aus., 5 New Cal.

Certain genera are confined to New Zealand, Australia and subantarctic South America; such are as follows: — Carpha (Cyperac.) 1 N. Z.-Aus., also to New Guinea, 1 Sub. S. Am.; Carex-Echinochlaenae 14 N. Z., 2 Aus., 2 Sub. S. Am.; Gaimardia (Centrolepidac.) 1 N. Z., 1 Sub. S. Am., 1 Aus.; Libertia page 410(Iridac.) 3 N. Z., 1 N. Z.-Aus., 1 Aus., 5 Sub. S. Am., Nothofagus (Fagac.) 5 N. Z,, 8 Sub. S. Am., 3 Aus. — the evergreen section has 5 N. Z., 2 Aus. and 3 Sub. S. Am.; Colobanthus (Caryophyll.) 10 N. Z., 1 N. Z.-Sub. S. Am., 1 Aus., 8 Sub. S. Am., and 1 Kerguelan Land and 1 New Amsterdam; Caltha-Psycrophila (Ranun.) 2 N. Z., 2 Aus., 7 Sub. S. Am., but extending northwards along the Andes; Drosera-Psychophila (Droserac.) 1 N. Z., 1 Aus., 1 Sub. S. Am.; Acaena-Euancistrum (Rosac), 2 N. Z., 1 N. Z.-Aus., 1 N. Z.-Sub. S. Am., 17 or more Sub. S. Am. and also 1 New Amsterdam and 1 Tristan d'Acunha — the above species taken mostly in a very wide sense; Geranium-Chilensia (Geran.) 1 N. Z.-Aus., 22 Sub. S. Am.; Geranium-Andina (Geran.) 1 N. Z.-Aus.-Sub. S. Am., 16 Sub. S. Am.; Discaria (Rhamnac.) 1 N. Z., 1 Aus., 18 Sub. S. Am. and northwards; Aristotelia (Elaeocarp.) 2 N. Z., 2 Sub. S. Am., also 1 New Heb. and 1 New Guinea; Drapetes (Thymelaeac.) 4 N. Z., 1 Aus., 1 Sub. S. Am., also 1 Mal.; Epilobium-Sparsaeflora (Onagrac.) 3 N. Z., 1 Aus., 1 Sub. S. Am.; Schizeilema (Umbell.) 11 N. Z., 1 Aus., 1 Sub. S. Am.; Lilaeopsis (Umbell.), 2 N. Z., 3 Aus., 4 S. Am. with 1 Sub. S. Am. also 3. North Am. and 2 N. Am.-S. Am.; Oreomyrrhis (Umbell.) 3 N. Z., 1 Aus., 7 S. Am. with 1 or more in Mexico; Pernettya (Ericac.) 20 Central Am. to the Falklands and represented in N. Z.-Aus. by the section Pernandra with 1 N. Z. and 1 Aus.; Gentiana-Antarctophila (Gentian.) 1 N. Z., 1 Tas., 1 Aus., 1 Sub. S. Am.; Hebe (Scroph.) 64 and more N. Z., 2 N. Z.-Sub. S. Am., 2 Aus., Ourisia (Scroph.) 12 N. Z., 2 Aus., 12 Sub. S. Am., 7 Subtrop. Andes; Plantago-Plantaginella (Plantag.) 1 N. Z., 2 Aus., 9 Andine, Mexico to Falklands; Selliera (Goodeniac.) 1 N. Z.-Aus.-Sub. S. Am., 1 Western Aus.; Donatia (Donatiac.) 1 N. Z.-Aus., 1 Sub. S. Am.; Abrotanella (Compos.) 9 N. Z., 3 Aus., 3 Sub. S. Am., 1 Rodriguez.

Coming now to the species, and excluding the cosmopolitan and subcosmopolitan, the number supposed to be common to New Zealand and Australia (probably few are truly identical) is 236 — pteridophytes 72 (43% of the New Zealand total), monocotyledons 80 (18.6%) and dicotyledons 84 (only 6.8%) — and 57 families and 139 genera are represented the largest of which are as follows: — (families) Filices 63 (26.6%), Cyperaceae 28, Gramineae 17, Orchidaceae 16, Juncacea 9, Compositaee 8 only, Lycopodiaceae and Scrophularinaceae 7 each; (genera) Juncus 8, Asplenium, Lycopodium and Cladium 6 each, Adiantum, Carex and Drosera 5 each.

The New Zealand-Australian species may be arranged in the following group to each of which the number of species is appended: — (1.) species of Australian origin (pteridophytes 10, monocotyledons 48, dicotyledons 33); (2.) species of New Zealand origin (pterids. 12, monocots. 12, dicots. 19); (3.) species with equal claim for either Australian or New Zealand origin (pterids. 10, monocots. 6, dicots. 18); (4.) species of palaeotropic origin (pterids. 38, monocots. 9, dicots. 7); (5.) species of subantarctic origin (pterids. 1, monocots. 4, dicots. 7); also there is the South African page 411Todaea barbara and Carex Gaudichaudiana with a vicarious representative in the temperate Northern Hemisphere. Taking the 3 systematic groups together the total number of species for each class is: Class (1.) 91, class (2.) 43, class (3.) 34, class (4.) 54 and class (5.) 12.

Leaving the ferns on one side, most of them common forest-plants, about 70 of the remaining 173 species may be considered common and 30 of these extremely abundant, while 103 species are of restricted distribution, many being confined to some small special habitat, and 27 of these are extremely rare. With regard to the vertical distribution of the 236 species under consideration, it is as follows: — coastal 22, lowland 134, lowland-montane 28, lowland-subalpine 39, lowland-alpine 3, montane 1, subalpine 3, montane-subalpine 3 and subalpine-alpine 3.

It may be seen from the above that the importance of the Australian element is easily exaggerated, as also the floristic relation between the two floras. A considerable part of the species common to both occurs only on the mountains of Tasmania and the higher Australian Alps. Many families and genera, characteristically Australian, are either absent or very poorly represented, e. g. Eucalyptus, Callistemon, Melaleuca and other Myrtaceae, Proteaceae of which there are but 2 species in New Zealand, Dilleniaceae, Tremandraceae, genera of Leguminosae, e. g. Acacia and Pultenaea, the important family Rutaceae with the genera Boronia and Eriostemon, Casuarina, various monocotyledonous genera &c. It is hardly going too far to say that it would be possible for one to have an excellent acquaintance with the botany of Eastern Australia and yet to be acquainted with very few indeed of the species which extend to New Zealand.

The Subantarctic element.

It is the presence of a well-defined element common to New Zealand, Eastern Australia and Tasmania, subantarctic South America, and the extra-New Zealand subantarctic Islands that has given rise to endless speculations as to its origin.

In the first place as to genera, many are common to New Zealand and Subantarctic South America &c., as shown in the following list where the mark † denotes that the genus to which it is attached is absent in the Australian flora: — Hymenophyllum, Trichomanes, Dicksonia, Cheilanthes, Pellaea, Cystopteris, Pteridium, Pteris, Blechnum, Asplenium, Polystichum, Polypodium, Notochlaena, Gymnogramme, Gleichenia, Schizaea, Ophioglossum, Botrychium (Filices.); Azolla (Salviniac.); Isoetes (Isoetac.); Lycopodium (Lycopod.); Dacrydium, Podocarpus (Taxac.); Libocedrus (Cupress.); Triglochin (Scheuchz.); Potamogeton (Potamoget.); Hierochloe, Agrostis, Deyeuxia, Deschampsia, Trisetum, Danthonia, Koeleria, sect. Dorsae-aristatae; Poa, Festuca, Bromus (Gramin.); Schoenus, Cladium, (Vincentia) 1 species Juan Fernandez, Oreobolus, Uncinia, Carex (Cyperac); Leptocarpus (Restion.); Gaimardia (Centrolep.); Rostkovia†, Marsippospermum†, Juncus, Luzula (Junc.); Enargea†, Astelia (Liliac); Libertia (Iridac.); Spiranthes (Orchid.); Notho-page 412fagus(Fagac.); Urtica (Urticac.); Phrygilanthus (Loranth.); Knightia (Proteac.); reported as fossil in Seymour Isld. close to Grahamland, Polygonum, Rumex, Muehlenbeckia (Polygonac.); Chenopodium, Atriplex, Suaeda, Salicornia (Chenopod.); Mesembryanthemum, Tetragonia, (Aizoac.); Montia (Portulac.); Stellaria, Colobanthus, Spergularia, Scleranthus (Caryoph.); Ranunculus, Myosurus, Caltha sect. Psychrophila(Ranun.); Laurelia(Monimiac.); Cardamine, Sisymbrium, Lepidium (Crucif.); Drosera sect. Psychophila (Droserac.); Tillaea (Crassulac.); Rubus, Geum, Acaena, (Rosac.); Edwardsia† (Legum.); Geranium (Geran.); Oxalis (Oxalidac.); Linum (Linac.); Callitriche (Callitrich.); Coriaria† (Coriariac.); Discaria (Rhamnac.); Aristotelia (Elaeocarp.-Aristotel.); Hypericum (Guttif.); Drapetes (Thymel.); Myrtus, Eugenia (Myrtac.); Viola (Violac.); Epilobium, Fuchsia† (Onagrac.); Halorrhagis, Gunnera, Myriophyllum, (Halorrhag.); Pseudopanax† (Araliac.); Azorella†, Schizeilema, Apium, Lilaeopsis, Oreomyrrhis (Umbell.); Griselinia† (Cornac.); Gaultheria, Pernettya (Ericac); Samolus (Primulac.), Gentiana (Gentian.); Calystegia (Convolv.);. Myosotis (Borrag.); Tetrachondra†, Scutellaria (Labiat.); Jovellana†, Limosella, Veronica, Ourisia, Euphrasia (Scroph.); Utricularia (Lentibul.); Plantago (Plantag.); Coprosma (Juan Fernandez.); Nertera, Galium (Rubiac.); Pratia (Campan.); Selliera (Gooden.); Phyllachne†, Donatia (Stylid.); Lagenophora, Gnaphalium, Cotula sect. Leptinella, Abrotanella, Senecio, Taraxacum (Compos.).

In the second place, as to species there are at least 58 identical, or almost so, in the New Zealand and Subantarctic floras which have remained unchanged, intense isolation notwithstanding. Moreover there are 44 vicarious species.

The species supposed to be identical are as follows: Hymenophyllum rarum, H. ferrugineum† (restricted to Juan Fernandez), H. tunbridgense, H. peltatum, Pteridium esculentum, Histiopteris incisa, Blechnum penna marina, B. procerum or a close ally, Aspelenium obtusatum, Polystichum vestitum, P. adiantiforme, Polypodium Billardieri, Schizaea fistulosa var. australis, Botrychium lunaria (ilic.); Agrostis magellanica†, Trisetum subspicatum, Festuca erecta† — in New Zealand only on Macquaries (Gramin.); Scirpus aucklandicus (Amsterdam Island only), S. cernuus, S. nodosus (of wide range), Uncinia macrolepis†, U. compacta (Kerguelen, Amsterdam Island), C. Darwinii var. urolepis†, C. pumila (of wide range), C. trifida†, C. Oederi var. cataractae (Cyperac.); Rostkovia magellanica†, Juncus planifolius (Jancac.); Tetragonia expansa — of wide range (Aizoac.); Montia fontana — cosmopolitan (Portulac.); Ranunculus acaulis†, — R. crassipes† (Ranun.); Cardamine glacialis† — var. carnosa is the New Zealand form (Crucif.); Tillaea moschata† (Crassulac); Geum parviflorum† — according to Skottsberg there are minor differences between the forms of the two regions, Acaena adscendens† — in New Zealand on the Macquaries only (Rosac.); Edwardsia tetraptera† in a wide sense — E. chathamica is very close to the Chilian plant (Legum.); Callitriche antarctica† (Callitrich.); Halorrhagis erecta† (Juan Fernandez), Myriophyllum elatinoides (Halorrhag.); page 413Hydrocotyle americana†, Azorella Selago† — in New Zealand confined to the Macquaries, Oreomyrrhis andicola in a wide sense, probably the forms of the two regions are distinct; Apium prostratum (Umbel.); Samolus repens (Primulac.); Myosotis antarctica† according to Skottsberg occurs in south Patagonia, in New Zealand it is restricted to Campbell Island (Borrag.); Calystegia tuguriorum†, Dichondra repens — sub-cosmopolitan (Convol.); Gratiola peruviana, Hebe salicifolia var. communis†, H. elliptica†, X H. ellipsala†, Limosella tenuifolia (Scroph.); Nertera depressa (Rubiac.); Selliera radicans (Goodeniac.); Cotula plumosa†, C. coronopifolia and Taraxacum magellanicum† (Compos.).

Equally important phytogeographically as the identical species are the vicarious, many of which have usually been considered identical. The following is a list of the visarious species, the name given first being the New Zealand species: — Azolla rubra—A. filiculoides (Salvinac.); Lycopodium fastigiatum—L. magellanicum (Lycopod.); Koeleria superba† — K. Bergii; Poa litorosa† — P. novarae (St. Paul, and New Amsterdam): Poa foliosa† — P. flabellata; Hierochloe redolens—H. magellanica; Festuca novae-zelandiae† — F. magellanica (Gramin.); Oreobolus pectinatus† — 0. obtusangulus; Carpha alpina—C. schoenoides; Schoenus pauciflorus† — S. antarcticus; Carex pseudocyperus var. fascicularis — var. Haenkeana (Cyperac.); Gaimardia setacea† — G. australis (Centrolep.); Marsippospermum gracile† — M. Reichei; Luzula crinita† — L. alopecurus; L. Traversii† — L. racemosa; Juncus sp. unnamed of New Zealand Subantarctic Islands† — J. scheuzerioides (Juncac.); Astelia linearis† — A. pumila; Enargea parviflora† — E. marginata (Liliac.); Nothofagus Menziesii† — N. betuloides (Fagac.); Rumex neglectus† — R. cuneifolius (Polygonac.); Colobanthus muscoides† — C. kerguelensis; Colobanthus Hookeri† — C. subulatus, C. mollis† — C. quitensis (Caryoph.), Myosurus novae-zelandiae—M. aristatus; Caltha novae-zelandiae—C. sagittata (Ranun.); Laurelia novae-zelandiae—L. aromatica and L. serrata (Monimiac.); Drosera stenopetala—D. uniflora (Droserac.); Geranium sessiliflorum var. glabrum† — G. sessiliflorum (Geran.); Oxalis lactea—O. magellanica (Oxalidac.); Coriaria sarmentosa† — C. ruscifolia; C. lurida† — C. thymifolia (Coriariac.); Discaria toumatow† — D. discolor (Rhamnac.); Drapetes Dieffenbachii† — D. muscosus Thymelaeac.); Epilobium pedunculare† — E. conjugens (Onagrac.); Hydrocotyle novae-zelandiae— H. marchantioides; Lilaeopsis novae-zelandiae— L. ovina (Umbel.); Tetrachondra Hamiltonii† — T. patagonica (Tetrachondrac.); Euphrasia zealandica— E. antarctica (Scroph.); Plantago Brownii—P. barbata (Plantag.); Pratia angulata† — P. repens (Canipan.); Donatia novae-zelandiae—D. fascicularis (Donatiac.); Lagenophora pumila† — L. Commersonii; Abrotanella muscosa† — A. emarginata; A. caespitosa† — A. linearis. The above list contains far more plants of a subantarctic character than does the list of identical species and they are no mere waifs page 414and strays but a definite systematic and especially ecological group, which appears to point to a much larger group many of the members of which have perished.

The palaeotropic element.

Under the term palaeotropic come the Malayan, Australian-Malayan, Melanesian and Polynesian elements of the flora. The element stands out ecologically as most distinct from the closely-related palaeozelandic and Subantarctic elements.

The following are the principal families and genera: — (families) Burmanniaceae, Pandanaceae, Palmae, Chloranthaceae, Moraceae, Loranthaceae, Santalaceae, Balanophoraceae, Nyctaginaceae, Monimiaceae, Lauraceae, Meliaceae, Euphorbiaceae, Icacinaceae, Corynocarpaceae, Elaeocorpaceae, Tiliaceae, Passifloraceae, Myrtaceae, Araliaceae, Myrsinaceae, Loganiaceae, Apocynaceae, Convolvulaceae, Verbenaceae, Gesneriaceae, Rubiaceae, Cucurbitaceae; (genera) Hymenophyllum, Trichomanes, Cyathea, Hemitelia, Alsophila, Dicksonia, Davallia, Leptolepia, Lindsaya, Adiantum, Cheilanthes, Pellaea, Paesia, Pteris, Doodia, Diplazium, Athyrium, Nephrolepis, Gymnogramme, Gleichenia, Lygodium, Marattia (Filic.); Tmesipteris, Psilotum (Lyeopod.); Agathis (Pinac.); Freycinetia (Pandan.); Imperata, Paspalum, Isachne, Panicum, Oplismenus, Cenchrus, Alopecurus, Eleusine (Gramin.); Mariscus, Fimbristylis, Cladium (Cyperac.); Rhopalostylis (Palm.); Xeronema, Cordyline (Lil.); Dendrobium, Bulbophyllum, Earina, Sarcochilus (Orchid.); Macropiper, Peperomia (Piperac.); Ascarina (Chloranth.); Paratrophis (Morac.); Elatostema, Boehmeria (Urtic.); Elytranthe, Loranthus, Korthalsella (Loranth.); Euphorbia, Homalanthus (Euphorb.); Pisonia (Nyctag.); Hedycarya (Monimiac.); Litsaea, Gassytha (Laurac.); Weinmannia (Cunon.); Pittosporum (Pittosporac.); Canavalia (Legum.); Melicope (Rutac.); Dysoxytum (Sapind.); Corynocarpus (Corynocarp.); Elaeocarpus (Elaeocarp.); Hibiscus (Malvac.); Metrosideros, Eugenia (Myrtac.); Meryta, Schefflera (Araliac.); Sideroxylon (Sapotac.); Geniostoma (Loganiac.); Parsonsia (Apocynac.); Ipomaea (Convol.); Myoporum (Myoporac.); Vitex, Avicennia (Verben.); Solanum (Solan.); Sicyos (Cucurb.); Scaevola (Gooden.); Siegesbeckia, Bidens (Compos.).

For the most part the species of the above genera are endemic, nevertheless they form, as already explained, a distinct element of the flora which is in large measure restricted to the frostless parts of the Region comparatively few species gaining the subalpine belt or in the south leaving the coast-line.

With regard to the identical species if the numerous palaeotropical pteridophyta, the fairly large widely-distributed tropical and subtropical element and the Norfolk-Howe species be here left out of consideration, the few remaining species shared by New-Zealand with other palaeotropic floras are Podocarpus ferrugineus (Podocarp.), New Caledonia only; Cenchrus calyculatus (Gramin.), but to Kermadecs only; Cladium articulatum, C. glomeratum, Gahnia gahniaeformis (Cyperac.); Macropiper excelsum (Piperac.); page 415Melicytus ramiflorus (Violac.); Metrosideros villosa (Myrtac.), but Kermadec only.

The cosmopolitan element.

Here the term Cosmopolitan is used with a wide significance, and all those species are included that have a considerable range in either temperate or warm climates. Some, especially those of warm countries, are ecologically akin to weeds, to that it is difficult, or impossible to decide, whether their present distribution has come about by natural means, or whether, also, some of those found in New Zealand are truly indigenous. Even regarding the well-known floras of European lands, exposed as these have been for long periods to the influence of man, it must be a matter of great uncertainty as to what species are actually indigenous, and, it may well be, that many species, concerning the nativity of which no question has ever been raised, have originated far from what is now the centre of their greatest distribution.

The most important section, from the phytogeographical standpoint, consists of those species supposed to belong without question to the Northern hemisphere, a matter however taken rather for granted than proved. These species fall into the two classes of those in which the northern and southern forms are almost identical and those in which a species or group of species in the north has one or more vicarious southern representatives.

The following are important examples: — (identical species) Hymenophyllum tunbridgense, H. peltatum, Asplenium Trichomanes, Botrychium lunaria — also in Australia and Subantarctic America, but only recorded from one locality in New Zealand (Filic.); Potamogeton natans, P. polygonifolius, Ruppia maritima (Potam.); Trisetum subspicatum (Gramin.); Carex pyrenaica — there is var. cephalotes but it is known only in two localities, both in South Otago, C. diandra — only known in New Zealand in the Southern Hemisphere, C. stellulata — only known in Australia and New Zealand in the Southern Hemisphere, C. lagopina — in the Southern Hemisphere, only in New Zealand, C. pseudo-cyperus (Cyperac.); Montia fontana (Portulac.); Callitriche verna (Callitrich.); Calystegia Soldanella (Convolo.); (vicarious species) Pteridium esculentum—P. aquilinum; Cystopteris novae-zelandiae—C. fragilis, Ophioglossum, coriaceum—O. lusitanicum, O. pedunculosum—O. vulgatum, Botrychium australe—B. ternatum (Filic.); Hierochloe Fraseri—H. alpina, Agrostis Dyeri—A. canina, Deschampsia caespitosa var. macrantha—D. caespitosa, Koeleria novo-zelandica—K. cristata, Festuca novae-zelandiae—F. rubra (Gramin.); Carex appressa and its allies — C. paniculata to which Cheeseman, following Bentham and von Mueller, referred the whole C. appressa group in 1884, C. Gaudichaudiana—C. Goodenoughii, to which under better-known name C. vulgaris, C. Gaudichaudiana was referred by Cheeseman in 1884, but as a variety, C. Oederi var. cataractae—C. Oederi (Cyperac); Zostera tasmanica — Z. marina Potam.); Juncus polyanthemus—J. effusus, which is naturalized only, page 416J. maritimus var. australiensis (might be treated as a species) — J. maritimus, the remarkable series of Luzulae referred by Buchenau to L. campestris but as varieties, most of which I consider excellent species and others hybrids between such — L. campestris (Juncac.); Urtica australis and its near allies — U. dioica (Urticac.); Chenopodium glaucum var. ambiguum — C. glaucum (Chenopod.); Cardamine heterophylla—C. hirsuta (Crucif.); Potentilla Anserina var. anserinoides—P. Anserina (Rosac.); Geranium pilosum—G. dissectum (Geraniac.); Elatine gratioloides—E. americana (Elatinac.); Epilobium Billardierianum—E. tetragonum (Onagrac.); Apium prostratum—A. graveolens (Umbel.); Sonchus littoralis—S. asper, only naturalized in New Zealand, Taraxacum magellanicum—T. officinale (Compos.).

The Lord Howe-Norfolk element.

Something has already been said concerning the above when dealing with the Kermadec Islands. Here only a few special details are necessary. The following are the identical and vicarious species which are confined to the two floras: — (identical) Gahnia xanthocarpa, Muehlenbeckia complexa var. microphylla; (vicarious) Mariscus ustulatus—M. haematodes, Edwardsia microphylla and its near allies — E. howinsula the name given by W. R. B. Oliver as a variety of the linneon E. tetraptera, Melicope ternata—M. contermina, Hymenanthera novaezelandiae either identical, or a closely-related species, or the Norfolk Island H. latifolia, Coprosma retusa—C. prisca but a matter of opinion whether to treat both as varieties of the compound species, C. Baueri. More important than anything in the above list, unless it be the occurrence of Edwardsia, is the presence on Lord Howe Island of a species of Carmichaelia (C. exsul) — a genus otherwise endemic in New Zealand — for it raises the question as to whether Carmichaelia had once a far-wider distribution than at present and that C. exsul is the sole survivor.

With regard to the New Zealand-Norfolk Island floristic relationship the following are the identical species not occurring elsewhere and the vicarious species: — (identical) Phormium tenax, Muehlenbeckia australis, Olea apetala; (vicarious) Adiantum obtusatum—A. difforme according to R. M. Laing, Cyclophorus serpens—C. confluens according to R. M. Laing, Rhopalostylis sapida and R. Cheesemanii—R. Baueri, Cordyline australis—C. Baueri, Pennantia corymbosa—P. Endlicheri, Hymenanthera novaezelandiae—H. latifolia, Suttonia kermadecensis (Kermadecs only) — S. crassifolia, Sideroxylon novo-zelandicum—S. costatum.

1 1) This is hardly true, for it contains species of two essentially different life-forms — the mat and the dense coushion — nevertheless both develop from the beginning upon exactly the same plan and the cushion-form arises from the mat-form through the coining in of filling material, either inorganic (blown silt, sand &c), as in the case of R. lutescens, or organic (dead rotting shoots &c.) as for R. Haastii of stony river-bed and the hard, massive "vegetable-sheep". Cheeseman defines all the species in his diagnosis of the genus (1925:967) as "perennial herbs", but all are more or less semi-woody and most of the vegetable-sheep true shrubs, though quite unlike shrubs in general.

2 2) Leucogenes Grahami Petrie, admitted as a species in the Manual, is most likely Helichrysum Selago ( Leucogenes grandiceps