The number of species found on North Island mountains is only about one-third of that found in the Southern Alps. The general pattern of mountain vegetation is found on Mt. Egmont where mixed rain forest gives place to shorter trees and shrubs; Libocedrus, mountains totara, hebes, shrubs of the daisy family, and tall tussock. Above are the alpine meadows and then the loose scoria in which few plants can maintain a footing. Lichens are prominent and some moss in boggy places. In the chain of the Ruahine-Tararua mountains there is the same general pattern and many of the same species are found.

The Central Plateau

That the type of soil is one of the most important factors in plant association is shown in the volcanic region, as in the Dun Mountain of Nelson. On the eastern slopes of Ruapehu there are extensive areas of scoria and at the base of the mountain much volcanic ash. These slopes have the same aspects as the nearby Kaimanawas, but instead of mixed rain forest, there is on Ruapehu a beech forest showing great variation in leaf form. The plant associations here are patchy, in places sheltered from sun and wind; Nothofagus fusca and N. cliffortioides are predominant. Under beech trees there is often a layer of fallen leaves up to 2 in. deep, in which little undergrowth survives.

The belt of shrubs above is dense and consists of Phyllocladus alpinus, species of Dacrydium, Coprosma, Olearia, Senecio, Hebe, and Nothopanax. Some of these, in upper limits, are prostrate or creeping. Smaller plants are Libertia pulchella, and some species of fern such as Hymenophyllum multifidum, Blechnum, and Polystichum spp. On the western slopes the belt of shrubs above the mixed forest is more like that of the Southern Alps. On Tongariro there are deep gullies, at altitudes of 4,000 to 5,000 ft where better soil has accumulated and growth is more dense. The dominant species is Phyllocladus alpinus with species of Dracophyllum, Nothopanax, Olearia, Coprosma, also Leptospermum scoparium and Gleichinia cunninghamii.

In some cases bogs occur only in certain seasons, and here Luzula colensoi is seen of very much greater size than in its usual habitat of dry scoria. Sphagnum moss occurs in bogs and may become the bed for germination of seed of manuka. Arundo conspicua, Drosera spathula (a carnivorous plant), and species of Carex may be found. As the streams are swift and icy, few algae are found. Close to the banks are Ranunculus rivularia, Celmisias, Juncus, and Epilobium. In hot springs at Ketetahi there are some blue-green algae and the fern, Hystiopteris incisa. On the pumice-covered plateau in the centre of the North Island and on the lower slopes of the three volcanoes, Ruapehu (9,175 ft), Ngauruhoe (7,515 ft) and Tongariro (6,458 ft), there is scrub formation, mainly of manuka (Leptospermum scoparium), with the attractive small shrub Gaultheria oppositifolia (snowberry), as well as G. colensoi and G. paniculata. There are eight species of Gaultheria, all endemic. G. rupestris is widespread in both Islands, and G. subcorymbosa and G. crassa are found on the Ruahine and Tararua Ranges and in the mountains of Nelson. These little shrubs have a profusion of small flowers, but the berries are larger and more showy. In this region is Dracophyllum subulatum, one of the grass trees, which lives on the poor soil of the volcanic plateau, on the Rangitaiki Plains, and in the Ruahine Range. D. stricta and D. recurvum are found in similar localities in the centre of the North Island sub-alpine regions. Other species of the genus are found in South Island sub-alpine regions, or in lowland areas.

Two species of Ranunculus, R. nivicolus, a slender erect herb, and R. carsei, a prostrate hairy shrub, also R. ignis, are found on the three mountains of the central plateau, and also on Mt. Egmont. The willow herbs, species of Epilobium, E. pernitens, E. perplexum, and E. cockaynianum, may be found in pockets of earth on the Ruahine and Tararua Ranges and on Mt. Egmont. The little eyebrights, Euphrasia monroi, and E. tricolor on Ruapehu, Tongariro, and Egmont are partly parasitic in habit. On the scoria slopes of these mountains there is very little vegetation, but several species of Parahebe, P. spathulata with a root of great length and small, succulent, hairy leaves, and P. hookeriana, a much-branched, woody prostrate shrub, do survive. On Mt. Egmont are masses of alpine foxglove Ourisia macrophylla, which is also common on the volcanic plateau and Ruahines, where O. colensoi, O. caespitosa, and O. vulcanica are also found. Another common plant is Celmisia glandulosa, also C. spectabilis in patches of damp ground. C. incana and C. hieracifolia, with Astelia montana, form a conspicuous part of the vegetation of the Ruahine and Tararua Ranges, while the edelweiss, Leucogenes leontopodium, grows in large masses in alpine regions from the centre of the North Island to Canterbury, but the other species, L. grandiceps, is in South Island only. Of the Olearias, O. nummularifolia and O. ilicifolia are widely distributed mountain species. Senecios are very common subalpine plants. The shrubby groundsels, S. eleagnifolius and S. adamsii, are found in the Tararua and Ruahine Ranges but most species occur only in the South Island.

Similar plant covering was found on the slopes of Mt. Tarawera before the eruption of 1886 when large areas were covered by volcanic ash, in some places to a great depth. Where the covering of ashes was but a thin one, the vegetation reappeared in almost its original form, but in other areas there were great changes. Following the eruption very heavy rain caused changes in the land, so that many gullies were formed in the loose soil. Here some new species became established from seed brought by birds or blown by the wind. Masses of toetoe, Arundo conspicua, are now seen, with much tutu, Coraria sarmentosa and cushion plants of Raoulia australis. Some plants described by early botanists have not been found since the eruption: such is the case of Utricularia mairii, one of the unusual bladderworts, found floating in Lake Rotomahana and described in 1872 by T. Kirk and G. Mair.

Among the plants of our mountains are many endemic species and most of these belong to only a few genera. The genus Celmisia, of which there are 58 endemic species, are the mountain daisies which have been regarded as the dominant plants of these regions. The flowers are white and usually large and beautiful. These are herbaceous plants, with leaves covered by hairs, and of shape and arrangements which seem to guard against loss of water by transpiration. In C. sessiflora, C. argentea, C. lateralis, and C. laricifolia are leaves of this nature. C. gracilenta is a species which is very widespread, being found throughout New Zealand from sea coast up to about 5,000 ft. C. spectabilis is also common and is recognised by a thick covering of buff-coloured hairs on under surfaces of leaves. Olearia is another genus with a large number of endemic species. These are shrubs or small trees with hard, leathery leaves having white or buff-coloured tomentum on the under surface. There are 32 species, all endemic. Olearia paniculata is found near the sea but also at great altitudes. O. moschata, mountain musk, is common in sub-alpine scrub as a tree 5 to 15 ft in height. O. ilicifolia is found throughout both Islands and O. avicenniaefolia is widespread at high altitudes.

The genus Hebe is a large one which is highly developed in New Zealand where 79 species are recorded, the largest number of any native genus. Most are endemic. They are found from sea coast to the upper limit of vegetation on our mountains. For many years this genus was known as Veronica, with the Maori name koromiko applied to many species. H. salicifolia is most widespread; H. traversii is common particularly on the Southern Alps, with H. monticola and H. epacridea in all mountain districts from Nelson southward to Otago. Many Hebes have minute scale-like leaves, overlapping and closely appressed to thin wiry stems. These are the whipcord hebes.

Aciphylla is another genus of which all the 39 species are endemic. Most of them have long thin spike leaves, forming a dense mass of fearsome appearance. The flower stalks are long, covered with spines, and bearing large panicles of flowers. When young the leaves are soft and may be eaten by cattle and sheep. Aciphylla monroi is found in alpine and sub-alpine regions. A. colensoi and A. squarrosa, kuri-kuri or wild Spaniard, are the best known and from the latter the Maoris obtained a scented gum.

We have some striking examples of the “cushion” habit of growth in the genera Raoulia and Haastia. When these plants grow to a large size the extensive mass with white hairy leaves has an unusual appearance which has given rise to the name “vegetable sheep”. Two species very common in the Southern Alps are Raoulia eximia and R. mammilaris, R. haastii is a much-branched prostrate herb of mountain river beds. There are 20 endemic species of Raoulia and the genus Haastia is also endemic.

The plants of the mountain regions are mostly evergreen, whether they are tiny plants, or grow as mats or cushions, shrubs or stunted forest trees. This is true even of those which are covered in snow for half the year. One of the first impressions, during the flowering season, is of the profusion of flowers, and at the same time of the lack of colour. The flowers are nearly all white, and many of the leaves appear grey due to the thick covering of hairs. Even those plants which are found in other parts of the world with coloured flowers, in the New Zealand mountain areas have white flowers. Gentians elsewhere are known for their bright blue colours, but the 24 species here are white, or very faintly streaked with colour. Our forget-me-nots are pale or deep yellow, though in sub-Antarctic Islands the forget-me-nots are blue as are the gentians. In fact, blue flowers are very rare in New Zealand; the little orchid Thelymitra is blue but Wahlenbergia gracilis, the blue-bell, is usually a dingy white. A number of flowers are yellow such as Helichrysum coralloides and several species of Senecio which include some of our most beautiful shrubs. S. lautus is the most common, S. bellidioides is abundant in sub-alpine regions, S. lyallii with white or yellow flowers is common in alpine passes, while S. scorzonerioides, the snow groundsel, one of the most showy New Zealand plants, is found on wet herb fields. Some Hebes have tiny pale mauve flowers, and Cotula atrata, found on shingle slips, has flowers which are almost black. In contrast to the lack of colour in flowers are shrubs with brightly coloured berries (Coprosma, Myrsine, Gaultheria).

The plants of mountain areas have certain characteristics which enable them to withstand extremes of climatic conditions. In sunshine the stony ground may become hot though the water beneath is icy cold; frosts may occur at all seasons of the year and perhaps last for several days, while periods of drought or of rain and mist, together with strong winds and the constant breaking of rocks on mountain screes, combine to produce an unstable habitat. So the plants found are those which can exist for a period without supplies of fresh water or which have very long root systems capable of penetrating far into the ground to reach water. Many have a mat or cushion form of growth able to withstand winds as well as frost and snow. The leaves may be tough and leathery or thick and fleshy (in which water is stored), and most of them have a dense covering of hairs on one or both surfaces, thereby checking the rate of transpiration. In that interesting group of Hebes known as the whipcords, the leaves are reduced to close-set scales on thin, hard stems. Many plants which grow erect in other situations are, in exposed habitats, prostrate shrubs, mats, or have rosette forms.

The alpine flora of New Zealand is vastly different from that of the lowland areas, and also vastly different from the mountain flora of other countries. Alpine plants are fascinating for the variety of their leaf forms and for the clear colour of their flowers, though in New Zealand their colour is usually white, cream, or yellow, the flowers being produced in great profusion. An alpine meadow in January is a beautiful sight with masses of large white cups of Ranunculus lyallii and the large daisy-like flowers of Celmisias. Both North and South Islands are mountainous, the latter extremely so, with the Southern Alps running almost its entire length. The snow line is the main factor determining the distribution of mountain plants and this varies greatly according to aspect and climatic conditions. At an average of 5,000 ft altitude a new type of vegetation appears, together with an abundance of certain plants seldom seen at lower levels. There are about 500 species of flowering plants found only in the mountains; with others, the total of mountain species is about 950.

The lowland rain forest is gradually replaced by shorter trees which become more and more stunted in growth and these give place to subalpine scrub. Shrubs of divaricating growth-form and those with stiff spiny leaves form dense masses which are almost impenetrable. Above this region are tall tussocks, herb fields, and alpine plants. The latter are often very small, only a few inches high, with inconspicuous greyish leaves, but beautiful flowers, found growing in small valleys or in the shelter of rocks.

At different levels are representatives of the lower groups of plants; fungi (especially in Nothofagus forest), lichens, mosses, and liverworts, also lycopods and some ferns, as species of Asplenium on limestone screes.

Although many adventive species have little or limited significance as weeds, being spectacular rather than serious, for example, the Californian poppy (Eschscholtzia californica), the adventive flora has definite economic importance because of the troublesome weeds it contains. It is not inappropriate then to consider briefly the ways by which adventive species entered New Zealand initially. The means of introduction fall into two categories:

1. Deliberate Introductions: Introductions of domesticated plants for particular purposes have yielded a number of escapes from cultivation, the main contributors being: (a) Agriculture: From pastures have come the common grasses and clovers of roadsides; from crops have come comfrey (Symphytum spp.), linseed (Linum usitatissimum), and lucerne (Medicago sativa); and from hedges have come broom (Cytisus scoparius), gorse (Ulex europaeus), hakea (Hakea spp.), and kangaroo acacia (Acacia armata). (b) Horticulture: Over 25 per cent of this flora has been derived from this source; from ornamental subjects have come Japanese honeysuckle (Lonicera japonica), the ornamental grass Pennisetum macrourum, sweet briar (Rosa rubiginosa), and watsonia (Watsonia bulbillifera); from culinary subjects have come blackberry (Rubus spp.), wild parsley (Carum petroselinum), and wild parsnip (Pastinaca sativa); and from herbal subjects have come hemlock (Conium maculatum) and thyme (Thymus vulgaris). (c) Forestry: From this source have come lodgepole pine (Pinus contorta var. latifolia) and Pinus radiata. (d) Aquaria, fish raising, water gardening: From these have come Canadian pondweed (Elodea canadensis), oxygen weed (Lagarosiphon major), and water hyacinth (Eichhornia crassipes). (e) Cage-bird seed: From this source come broomcorn millet (Panicum miliaceum), Guizotia abyssinica, and Indian hemp or marihuana (Cannabis sativa).

2. Unintentional or Accidental Introductions: The greater proportion of the species in the adventive flora were accidental introductions due to: (a) Impurities in agriculture seeds. It is estimated that ±55 per cent of the total had this origin. Even in recent years with modern seed-cleaning techniques, impurities still arrive, as in French lucerne, hedge bedstraw (Galium mollugo) and yellow star thistle (Centaurea solstitialis); in carrot seed, barnyard grass (Echinochloa crus-galli), and (Trifolium cernuum); in linen-flax seed, cut-leaved mustard (Sinapis dissecta). (b) Ballast. This was a fruitful source in sailing days; Paspalum dilatatum and yellow weed (Galinsoga parviflora) are examples. (c) Impurities in grain imported for flour or stock feed. The Mexican poppy (Argemone mexicana) and saffron thistle (Carthamus lanatus) are being repeatedly introduced, and recently three European weeds of the cabbage family, coming in via bulk wheat for flour, have been appearing about ports, railway sidings, and flourmills. (d) Twitch-like stems in dirt about the roots of commercial plants such as field horsetail (Equisetum arvense), a spore-producing ally of the ferns, in the roots of Iris sp. from Japan, and gout weed (Aegopodium podagraria), with imported ornamental shrubs. (e) Impurities in horticultural seeds. Several species have appeared including a European plantain (Plantago arenaria) in night-scented stock beds. (f) In packing of merchandise. The horned poppy (Glaucium flavum), common about the shores of Wellington Harbour, came in with the Patent Slip machinery in the 1870s, and others have come in with plate glass, whisky, crockery, and other goods. (g) In packing of military equipment. A ripgut grass (Bromus rubens) came in with the American Armed Forces in the Second World War and established itself near Paekakariki. (h) Impurities in cage-bird seed. One noteworthy newcomer in recent times was the large, spiny-fruited, poisonous thorn apple (Datura ferox) at Geraldine. (i) Attached to merchandise. A number of tropical weeds, including the troublesome khaki weed (Alternanthera repens) came to North Auckland with imported fertiliser; an Argentine evening primrose (Oerothera longiflora) established itself about a hardwood sleeper dump at Christchurch, as did the American ragweed (Ambrosia artemisiifolia), which came in with American-manufactured railway lines. (j) Attached to or associated with imported animals. Kangaroo grass (Themeda triandra) was introduced to the Wairau Valley, Marlborough, with Merino sheep from Australia; and recently, at Oamaru, pods of snail clover (Medicago scutellata) came in with an Australian sheep crate.

The possible means of introduction are legion. How many species have been brought in attached to clothing, in trouser cuffs, or in mud on the footwear of overseas travellers is not known, but, from mud brushed off boots used in New Caledonia, over 350 plants have been grown, representing 35 species, with lesser numbers from footwear used in Curacao, Fiji, and Chile.

The expansion of New Zealand's overseas trade and increased importing of a wide range of products from many different regions of the world indicate that, if past history is any criterion, the species of adventive flora will steadily increase, with the further possibility of the arrival of some troublesome weeds amongst future introductions.

by Arthur John Healy, M.AGR.SC., Assistant Director, Botanical Division, Department of Scientific and Industrial Research, Lincoln, Canterbury.

The adventive flora may well have had its beginnings with the arrival of the Maori voyagers from A.D. 1150 onwards, with the probable introduction of “stowaway” plants in dirt about the roots of their food and fibre plants. The formal history of the adventive flora begins, however, with the recording of a Mediterranean canary grass (Phalaris canariensis) in 1786 by George Forster, a botanist on Captain Cook's second voyage of discovery. Whalers, sealers, and timber seekers were responsible for the introduction of further species, the number rising sharply with the onset and expansion of organised colonisation. With this came the widespread modification (at times complete destruction) of the aboriginal vegetation and the introduction of a range of agricultural and horticultural plants, accompanied by a wide variety of impurities. The two necessary prerequisites for the successful establishment of an adventive flora were being realised – provision of bare ground or living space by the disturbance of existing vegetation and the introduction of a range of non-native species. Contrary to the views expressed last century by prominent overseas botanists that adventive species were superior to the native species and vegetation which they would in time displace, the true position is that adventive species did not enter into and establish themselves in primitive vegetation. Before this could take place, some disturbance or modification by man and his agents (firing, cultivation, grazing, etc.) was necessary.

Although in this article only ferns and flowering plants are considered, the adventive flora in the broadest sense covers a wide spectrum of the plant kingdom, including species of bacteria, fungi, lichens, and mosses. This flora has built up steadily to the extent that, over a period of nearly 180 years, the flowering plants and ferns growing outside of cultivation number more than 1,500 species.

Most major geographical regions of the world are represented in the adventive flora; Australia has contributed kangaroo wattle (Acacia armata); South Africa, Cape weed (Cryptostemma calendula); tropical Africa, woolly nightshade (Solanum auriculatum); North Africa, apple of Sodom (Solanum sodomaeum); South America, nassella tussock (Nassella trichotoma) and Onehunga weed (Soliva valdiviana); Central America, mist flower or Mexican devil (Eupatorium adenophorum) and Oxalis (Oxalis latifolia); North America, Canadian fleabane (Erigeron canadensis); Europe, foxglove (Digitalis purpurea); Asia Minor, Grecian thistle (Chamaepeuce afra); Western Asia, horehound (Marrubium vulgare); India, Cotoneaster simonsii; Eastern Asia, Manchurian wild rice (Zizania latifolia) and strawberry-raspberry (Rubus illecebrosus); and the Pacific region, nutgrass (Cyperus rotundus).

The adventive flora, as distinct from the native (indigenous) and the cultivated plant floras, consists of all plant species which are not native of New Zealand and grow spontaneously outside of cultivation; examples of adventive species are wheat growing along a railway track, gorse in a pasture, or hemlock in a pasture. It is a significant flora, not only because some of its members play an important role in the vegetation by forming distinct communities alone or with native species, but also because it contains the majority of our most troublesome weeds. There are now few landscapes at lower altitudes in which adventive species are not prominent; some species are so widely distributed and are in such harmony with their adopted countryside as to have every appearance of their being natives here, and are sometimes mistaken for them.

(Order: Diptera)

The fauna of flies is extensive and widespread throughout New Zealand and the off-shore islands, every type of habitat available in the New Zealand environment being occupied by some members of the order. A few of the 1,850 species so far known are of economic importance. These include houseflies, mosquitoes, and midges in the field of public health, blowflies and ked (sheep tick) in animal husbandry, leaf miners and root maggots in plant husbandry.

The more primitive sub-order (Nematocera) is well represented in the New Zealand fauna and most of the moist forests of the North Island and parts of the South Island have provided ideal ecological habitats for the evolution of numerous species. Thus New Zealand has a very strong crane fly fauna with at least 600 endemic species already described. Gnats are abundant and some species are present in very large populations. About 300 species are known, including the glow-worm. Mosquitoes and sandflies are exceedingly numerous in some moist bush localities and around some areas of the sea shore. In all, about 12 species of mosquitoes and eight species of simuliid sandflies are known. Midges likewise have huge populations of adults and of larvae (blood-worms) and New Zealand probably has more than 50 endemic species. There are many species of the biting midge family but only one species in New Zealand is known to bite. There are indications of a strong representation of the gall-midge family in New Zealand.

The more highly evolved flies of the sub-order Brachycera are with some exceptions not represented by large numbers of species in any family. The exceptions are the Dance flies and Dolichopodid flies. Both these families are represented by well over 100 endemic species. The large predacious flies are fairly common and some are the most striking and conspicuous members of the fly fauna. Among such flies are the horse flies, soldier flies, and robber or assassin flies. Most of them are beneficial in that they attack other insects. Hover flies are by no means uncommon and several species are important predators of aphids. There is a strong representation of species of small flies of size ranging from 2 to 4 mm. They belong to the acalypterate group of the sub-order. They are rarely noticed in the field but are of interest because they include the leaf-mining flies, the small fruit flies of the well-known genus Drosophila, the true fruit flies (which in New Zealand do not attack fruit but rather the seed heads of the Compositae), the shore flies of brackish water, and the kelp flies. The most highly evolved flies are the Muscids which in the widest sense include the houseflies, stable flies, biting flies, blowflies, and the many parasitic tachinid flies. A fauna of blood-sucking wingless parasitic flies is present on warm-blooded animals and on birds in New Zealand but no study has yet been made of them.

by Roy Alexander Harrison, D.SC., Senior Lecturer in Agricultural Zoology, Lincoln Agricultural College.

(1886– ).

Industrialist.

A new biography of Fletcher, James appears in the Dictionary of New Zealand Biography on this site.

James Fletcher who was born at Kirkintilloch, Scotland, on 29 March 1886, was educated in Glasgow and came to New Zealand in 1908, when he established a building business. With his brother he formed the firm of Fletcher Brothers, which became in 1919 the Fletcher Construction Co. and, in 1940, Fletcher Holdings. During the Second World War he was Commissioner of Defence Construction, Superintendent of Military Works, and Controller of Shipping. His many interests include the I.C.I., the Tasman Pulp and Paper Co., and New Zealand Paper Mills. The ramifications of the business have spread into many fields, and today it is the largest organisation of its kind in the country concerned with building and developmental enterprises. He was knighted in 1946.