Other formats

    TEI XML file   ePub eBook file  

Connect

    mail icontwitter iconBlogspot iconrss icon

Tuatara: Volume 9, Issue 2, November 1961

A Key to the Coprosmas of New Zealand — Part II

page 43

A Key to the Coprosmas of New Zealand — Part II

The Maori people of New Zealand discovered and used a yellow dyestuff from the bark of Coprosma australis and C. lucida to colour their flax cloth. A cut in either of these trees near ground level shows the inner bark to be vividly yellow or orange and would suggest possible tinctorial properties to a sharp observer. The colour is most intense in or near the root and best developed in older trees, but even in seedlings; the root system of these species is yellow coloured. This provides a simple distinction between the seedlings of pigmented and non-pigmented Coprosmas such as C. lucida whose yellow roots clearly contrast with the dull brown roots of C. robusta. These species are otherwise easily confused in their young stages.

After the discovery of synthetic dyes, natural dyestuffs declined in importance and were largely superseded. However, during the First World War synthetic khaki dyes were difficult to obtain, and Aston was led to investigate systematically the dyeing properties of Coprosmas, illustrating his published results by actual samples of dyed wool. Depending on the mordant and the process used to extract the dye liquor from the Coprosma bark, he found a variety of colours could be produced, including black, orange, yellow, maroon and page 44 shades of brown. He also showed that differences in the colour of the bark are exhibited by many Coprosma species, and that the colour often changes characteristically on addition of sodium hydroxide solution.

The chemical investigation of Coprosma begun by Aston has been developed and extended by Professor Briggs and research workers at the University of Auckland. They have shown quite a number of the colouring matters of C. australis, C. lucida, C. areolata, C. acerosa and C. rubra to be anthraquinone derivatives, having the following structure: Diagram of an anthraquinone derivative The different derivatives have the basic three-ring structure with one or more of the numbered positions substituted. Coprosma lucida bark has no less than eight free anthraquinone derivatives including anthragallol, this being its first recorded occurrence in nature. By contrast, the stem bark of C. arborea, C. tenuifolia, C. pumila, C. repens, C. rhamnoides, and C. robusta is devoid of anthraquinones, and these species therefore possess no dyeing qualities. The bark of C. arborea and C. tenuifolia does include a small percentage of sucrose.

One of the famous dyestuffs of ancient times was madder, a red dye extracted from the crushed roots of Rubia tinctorum, which was known in ancient India and predynastic Egypt. It is interesting to note that the dye compounds of madder, alizarin, rubiadin and purpurin, are substituted anthraquinones. Thus the botanically related Rubia and Coprosma are also found to be chemically allied. There is hope that chemical studies of Coprosma species may provide supplementary information on their relationships, and certainly the chemical facts gained must be taken into account with the other evidence in any systematic arrangement, although they cannot take precedence over the traditional methods of taxonomy. The field most susceptible to chemical investigation is undoubtedly the elucidation of hybrids.

Taxonomists who have studied Coprosma have been unanimous in complaining of the difficulties both of defining the limits of its variable species, and of classifying individual plants. In fact anyone who has tried to identify Coprosmas will be heartened to know that page 45 Cheeseman summed up the genus as the most puzzling in the New Zealand flora apart from Hebe. In areas being recolonised after disturbance, such as road cuttings, slips, burn scars, flood plains and even fire breaks, or the floor of ageing Pinus plantations where the canopy is opening to admit light, it is noticeable that Coprosma populations can be very variable, whereas in more stable habitats they tend to be more uniform. Some of the variability was accounted for when in 1919 Cockayne crystallised his growing suspicion that hybridism is rife in the New Zealand flora, by making a definite suggestion that Coprosma cunninghamii is a hybrid between C. robusta and C. propinqua. Ten years elapsed before Allan had crossed the presumed parents artificially and raised two generations of progeny, but his plants proved beyond doubt that Cockayne had been right. Cockayne and Allan published a list of hybrids in 1934. including 23 inter-specific crosses for Coprosma, of which they regarded only two as debatable. The diploid chromosome number for all New Zealand species that have been counted is 44, and the chromosomes themselves are small and difficult to study. However, in a list of chromosome numbers of Macquarie Island plants. Coprosma pumila is reported to have 2n = about 154. It seems that eytology does not furnish an easy method for studying hybridism if many species have the same chromosome number, but it may be useful in some cases. The direct approach by conducing breeding experiments takes up a great amount of time and requires a massive enthusiasm for gardening, but would probably be very rewarding.

An interesting recent biochemical approach to the problem has been the study by A. O. Taylor of variations in C. robusta, C. propinqua var. propinqua and C. propinqua var. latiuscula using in particular the polyphenolic compounds (e.g. tannins, flavones and catechins). This group of substances as a whole is widespread in the higher plants and is primarily responsible for properties like the distinctive taste and smell of tea and coffee. A pattern of polyphenols occurring in the young shoots was worked out for the three taxa, and as the situation in C. propinqua var. latiuscula was found to be intermediate between the other two, it was concluded that this variety probably originated as their hybrid. This may prove to be a relatively quick and reliable method which could be extended to determine the parentage, or detect other hybrids in the genus. In connection with polyphenols it is interesting to recall that J. C. Crawford once served ‘coffee’ made from roasted, ground Coprosma seeds at a meeting of the Wellington Philosophical Society. Laing and Blackwell mention the incident but dismiss it lightly. remarking that it was not repeated. Nevertheless the polyphenolic content in Coprosma is rich enough to justify optimism, and the leaves might be tried for brewing an aromatic ‘tea’ with a reasonable chance of success.

page 46

In his comprehensive monograph of Coprosma, Oliver put forward a theory of relationships and evolution within the genus which depends on the assumption that smaller and simpler species are primitive, and gave rise by a progressive growth and multiplication of parts to the large-leaved tree species. It is equally possible to read the Coprosma series in reverse order, and regard the smaller simpler species as derived by reduction from the larger. Carrying this hypothesis a step further, Nertera could be regarded as an herbaceous genus derived from Coprosma and filling niches at the geographical and ecological limits of Coprosma distribution. Evidence for this second theory is not altogether lacking. We know that New Zealand had a mild, equable climate before the Ice Age. and divaricating, semi-prostrate and mat forms in Coprosma indicate an adaptation to rigorous conditions which would have been unnecessary until the glacial period, and could have been evoked in response to it. With the return of more favourable conditions the surviving diversified Coprosma flora may have been reinforced by the arrival of some forest forms from the north, and a burst of speciation occurred which is still in progress as indicated by the variation and hybridism in the genus. The high polyploid chromosome number reported for C. pumila from Macquarie Island also seems to argue against its being an ancestral form.

The present key deals with the small-leaved species of Coprosma, or those with leaves generally less than an inch long. As in the previous key the emphasis is on vegetative characters, leaf shape and stipules being the most important. In species with leaves in fascicles, stipules can be hard to find, it being necessary to observe them on a ‘leader’ shoot with undeveloped axillary buds. As in many cases it is necessary, and in all it is desirable to have supplementary information for checking identifications, there is also a descriptive list of species which can be amplified by consulting a standard flora. Nomenclature follows Allan's Flora of New Zealand, with a minor deviation in the case of C. rhamnoides. This is a highly polymorphic species, as its leaves vary from linear through oval to rounded, and all kinds may sometimes be found on one branch. Allan followed Oliver in distinguishing two species from the assemblage of different forms, C. rhamnoides with thicker, more leathery leaves, which is roughly the North Island form, and C. polymorpha with thin leaves, most abundant in the South Island. In this key both are included as C. rhamnoides. Similarly, C. intertexta has been included in C. brunnea. Some of the other possibly difficult species are C. parviflora, C. pseudocuneata, C. cheesemanii and C. rigida, where each name covers more than one taxonomic entity, some or all of which may perhaps be worthy of higher rank.

Finally, a reminder that Coprosma is a notoriously variable genus and Cheeseman's warning advice should always be kept in mind when dealing with it: page 47 'In attempting to determine the species of Coprosma, really good and well-selected specimens showing both foliage and flowers are indispensable. Both sexes should be collected; and, as important characters are often afforded by the fruit, it should be obtained also, if possible from the same plant from which the female flowers were taken, notes being preserved of the shape, size, colour and other characters lost in drying. Note should also be kept of the habit and mode of growth, some of the closely allied species being easily distinguished by that alone. As the characters on which the species are founded are to a great extent comparative, the student must not expect to make much progress until he has collected a considerable number of the species and carefully compared one with another. It is thus no easy matter to identify the species, even when they are examined in a fresh state, while in the case of dried specimens, it requires the utmost care to arrive at any satisfactory conclusions.

There will probably always be some specimens which it is impossible to name. But after all, to name is not necessarily to understand, and it is more honest as well as scientifically useful to admit bafflement than to make a perfectly labelled herbarium collection giving the false impression that no doubts remain. In Coprosma there are still many uncertainties awaiting further study. Here is a rich field for both amateur and professional, the very difficulty of which presents a challenge and hope of reward that better defined taxonomic groups do not.

Section B Small-Leaved Coprosmas

1 Plant has a strong unpleasant smell when broken. — 2
Plant without an unpleasant smell. — 3
2 Plant low and scrambling, leaf notched at the tip, pubescence of young stems occurs in a longitudinal groove below the stipule (Figs. 10, 29). crenulata
Plant an erect shrub or small tree, leaf tip variously pointed, rounded or notched, with the midrib projecting into a small point, longitudinal groove below the stipule usually hairless or with a few sparse hairs (Fig. 2). foetidissima
3 Plant completely prostrate and mat forming. — 4
Plant shrubby, or if scrambling not mat forming. — 5
4 Leaf narrow-oval and pointed, with scattered white hairs at least when young, stipule margin slightly convex with a few tiny denticles amongst the fringe of short hairs, branchlets pubescent (Fig. 57). petriei
Leaf typically diamond-shaped, hairless, stipules bluntly triangular with a well-developed median denticle and short marginal hairs, branchlets hairless (Fig. 56) pumila
5 Leaf rounded and thick with a whitish bloom on the lower surface (Figs. 6, 31). crassifolia
Leaf without whitish bloom. — 6page 48
6 At least some leaves regularly truncate or notched at the tip. 7
Leaves never notched or truncate. — 13
7 Leaf with colourless border and minute crenulations on the margin especially towards the tip. — 2
Leaf without colourless crenulate border. — 8
8 Stipules with a dense fringe of white tangled hairs aggregated into a central tuft obscuring the denticle (Figs. 9, 30). astonii
Stipules hairless, or with a fringe of short hairs not obscuring the median denticle. — 9
9 Stipule bluntly triangular with a small median denticle (Figs. 1, 32). rigida
Stipule with a central ridge crowned by a prominent median denticle. — 10
10 Leaf with an approximately parallel-winged petiole, as long as or longer than the blade, domatia like tiny pinholes. 11
Leaf without a long parallel-winged petiole, domatia large, with a conspicuous raised area above and a round or oval slot entrance below. — 12
11 Pubescence of young stems (if present) is evenly distributed and pigmentation uniformly dark, bark of older stems brownish, lower surface of leaf has a clear pattern of small veins between the main secondaries extending close to the midrib (Figs. 5, 38). juv. arborea
Pubescence of young stems occurs in a longitudinal tract below the stipule and the greenish colour of young leaf bases and stipules contrasts with darker pigmentation above and below, bark of older stems whitish, lower surface of leaf has an obscure pattern of small veins between the main secondaries fading out altogether towards the midrib (Figs. 8, 35). spathulata
12 Leaf long and narrow (Figs. 4, 36). banksii
Leaf broad and round (Figs. 3, 34). colensoi
13 Leaf bearing hairs on one or both surfaces (use lens). — 14
Leaf not bearing hairs. — 18
14 Leaf bearing hairs above and below as well as in a prominent marginal fringe. — 15
Leaf bearing hairs on one leaf surface only, marginal hairs inconspicuous or absent. — 16
15 Leaf rounded and narrowed abruptly into a long petiole, domatia have a conspicuous tuft of close fur, and leaves, petioles, stipules and young branchlets bristle with long brownish hairs, stipules tubular and sheathing (Figs. 20, 47). rotundifolia
page 49
PLATE I 1a-d, C. rigida; 2a-c, C. foetidissima; 3a-b, C. colensoi; 4a-c, C. banksii; 5a-c, C. arborea juvenile; 6a-c, C. crassifolia; 7a-c, C. wallii; 8a-c, C. spathulata; 9a-c, C. astonii; 10a-b, C. crenulata; 11a-c, C. propinqua var. propinqua; 12a-c, C. propinqua var. latiuscula; 13a-c, × C. cunninghamii. (Figures one and a third times natural size.)

PLATE I
1a-d, C. rigida; 2a-c, C. foetidissima; 3a-b, C. colensoi; 4a-c, C. banksii; 5a-c, C. arborea juvenile; 6a-c, C. crassifolia; 7a-c, C. wallii; 8a-c, C. spathulata; 9a-c, C. astonii; 10a-b, C. crenulata; 11a-c, C. propinqua var. propinqua; 12a-c, C. propinqua var. latiuscula; 13a-c, × C. cunninghamii. (Figures one and a third times natural size.)

page 50
Leaf variably rounded or oval but without a distinct petiole, hairs on the leaf surface generally sparse and not usually as conspicuous as the marginal ones which form a regular eyelash fringe, young branchlets pubescent, stipules triangular, not sheathing (Figs. 21, 46). ciliata
16 Hairs long, silky and white, borne on the lower surface of the leaf and on stipules and branchlets, leaf has a ‘marbled’ appearance and very clear arching secondary veins when held up to the light (Figs. 16, 42). areolata
Hairs short and bristly, not obvious to the naked eye (use lens) but imparting a rough or ‘blotting paper’ feel to the leaf. — 17
17 Hairs present on the lower surface of the leaf, very clear arching secondary veins as well as a fainter network visible below, stipules triangular with a small median denticle, leaf sometimes has a ‘marbled’ appearance and a yellowish blotch near the base, leaf usually symmetrical (Figs. 15, 45). tenuicaulis
Hairs present on the upper surface of the leaf, a few on the margin towards the apex make the edge appear irregular, secondary veins neither strongly arched nor more obvious than the vein network below, stipules triangular with a long median denticle, leaf often markedly asymmetrical (Figs. 18, 41). rubra
18 Stipules joined above each pair of leaves to form a tube sheathing the stem. — 19
Stipules not so joined. — 24
19 Stipules of sheath type, sometimes bearing hairs but they never obscure the prominent median denticle, branchlets slim, leaf usually flat. — 20
Stipules of mixed type, with both sheath and cup, denticles obscured by a fringe of dense hairs, branchlets stocky, leaf often folded slightly about a depressed midrib. — 23
20 Leaf uniformly narrow, blade tapering evenly into petiole. 21
Leaf broader at the blade and more or less abruptly narrowed into a parallel-margined petiole. — 22
21 Branchlets and stipules very dark, stipule tube about 5 mm. long and crowned by a denticle and tuft of whitish hairs, stipules very persistent, not becoming papery with age, midrib straight (Figs. 28, 58). linariifolia
Branchlets and stipules light greyish or brownish, stipule tube about 2.5 mm. long or less and conspicuous only at branchlet tips, stipules deciduous, becoming thin and papery with age, midrib often changes direction at a domatium (Figs. 11, 50). propinqua var. propinqua
page 51
PLATE 2 14a-e, C. rhamnoides; 14f-k, C. rhamnoides (= polymorpha); 15a-c, C. tenuicaulis; 16a-d, C. areolata; 17, C. virescens; 18a-b, C. rubra; 19a-f, C. parviflora; 20a-b, C. rotundifolia; 21a-d, C. ciliata; 22a-c, C. microcarpa; 23a-c, C. cheesemanii; 24a-c, × C. kirkii; 25a-d, C. acerosa; 26a-c, C. antipoda; 27a-c, C. rugosa; 28a-b, C. linariifolia. (Figures one and a third times natural size.)

PLATE 2
14a-e, C. rhamnoides; 14f-k, C. rhamnoides (= polymorpha); 15a-c, C. tenuicaulis; 16a-d, C. areolata; 17, C. virescens; 18a-b, C. rubra; 19a-f, C. parviflora; 20a-b, C. rotundifolia; 21a-d, C. ciliata; 22a-c, C. microcarpa; 23a-c, C. cheesemanii; 24a-c, × C. kirkii; 25a-d, C. acerosa; 26a-c, C. antipoda; 27a-c, C. rugosa; 28a-b, C. linariifolia. (Figures one and a third times natural size.)

page 52
22 Shrub densely divaricating or sometimes emi-scrambling, leaf trowel-shaped or oval, midrib and a few main secondaries the only veins visible on the lower surface, leaf usually less than 1 cm. long (Figs. 12, 51). propinqua var. latiuscula
Shrub normally branched and erect, leaf broad or narrow oval with an apical point, a network of veins visible between the main secondaries on the lower surface, leaf usually more than 2 cm. long (Fig. 13). × cunninghamii
23 Plant low and scrambling, leaf oval, narrowed at the base into a short or longer petiole and bearing a conspicuous tuft of close white fur at the tip when young (Fig. 37). depressa
Plant an erect shrub, leaf oval or slim and pointed, narrowed at the base into a short petiole, leaf tip hairless (Fig. 39). pseudocuneata
24 Leaf narrow, with midrib the only conspicuous vein. — 25
Leaf broader, with secondary veins or a network visible on the lower surface at least. — 33
25 Stipules with a slightly convex margin, cup type. — 26
Stipules triangular, not strongly cupped. — 30
26 Plant an erect shrub. — 27
Plant low and scrambling or semi-prostrate with branches ascending towards the tips. — 28
27 Branchlets greyish, slender, neither strongly divaricating nor swollen at junctions, leaf thin, widest near the tip where the 1 or 2 domatia occur (Figs. 26, 52). antipoda
Branchlets reddish, stout, and strongly divaricating at right angles, swollen at junctions, leaf thick, domatia extremely rare (Figs. 27, 55). rugosa
28 Plant semi-prostrate with branches ascending towards the tips, leaf more than 3 mm. broad with a few obscure secondary veins almost parallel to the margin (Fig. 24). × kirkii
Plant strongly divaricating, scrambling and intertangled, leaf usually less than 1.5 mm. broad with midrib the only visible vein. — 29
29 Branchlets yellowish and smooth with a small amount of pubescence in a longitudinal strip below young stipules (Fig. 25). acerosa
Branchlets brown or grey, transversely ridged when older, conspicuous pubescence completely encircling the stem below young stipules (not illustrated). brunnea
30 Midrib distinct only near the leaf base, leaf margin with a thickened border, apex of mature leaves usually blunt and surmounted by a small colourless pointed projection (Fig. 33). obconica
page 53
PLATE 3 29, C. crenulata; 30, C. astonii; 31, C. crassifolia; 32, C. rigida; 33, C. obconica; 34, C. colensoi; 35, C. spathulata; 36, C. banksii; 37, C. depressa; 38, C. arborea juvenile; 39, C. pseudocuneata. (Figrues twice natural size.)

PLATE 3
29, C. crenulata; 30, C. astonii; 31, C. crassifolia; 32, C. rigida; 33, C. obconica; 34, C. colensoi; 35, C. spathulata; 36, C. banksii; 37, C. depressa; 38, C. arborea juvenile; 39, C. pseudocuneata. (Figrues twice natural size.)

page 54
Midrib visible the length of the leaf, leaf margin without a thickened border, or border restricted to near the apex, leaf apex not as above. — 31
31 Leaf wider towards the tip, apex not usually pointed (Figs. 19, 48, 49). parviflora
Leaf with parallel sides or wider towards the base, apex pointed. — 32
32 An erect shrub with a main stem, branchlets forming flat sprays, leaves thin and flat often curved in the plane of the leaf, usually with a matt upper surface, margin not thickened, stipules dark with a small central tuft of white hairs (Figs. 22, 53). microcarpa
A semi-scrambling or erect shrub without a main stem, branchlets not forming flat sprays, leaves thick, leathery and shining, usually folded about the midrib and curled, sometimes yellowish or bronze, margin with a reddish thickened border towards the tip, stipules and branchlets pale, slightly pubescent (Figs. 23, 54). cheesemanii
33 Leaf shape variable, including rounded, oval or diamond shaped, and narrow to almost linear (Figs. 14, 40, 43, 44). rhamnoides
Leaf shape uniform. — 34
34 Leaf narrow with more or less parallel margins and one or two pairs of secondary veins running nearly parallel to the midrib. — 35
Leaf not uniformly narrow, secondary veins arched at an angle to the midrib. — 36
35 Stipules strongly cupped, with small marginal denticles scattered amongst hairs, domatia of the leaf rare and inconspicuous (see 28), (Fig. 24). × kirkii
Stipules sheathing, with a single median denticle usually placed slightly forward of the stipule margin at the tip of the median ridge, domatia of the leaf usually conspicuous, sometimes displacing the midrib slightly (see 20), (Figs. 11, 12, 50, 51). propinqua
36 Leaf rounded, thick and blunt at the apex (Fig. 7). wallii
Leaf not rounded and thick. — 37
37 Leaf widest towards the apex and steadily narrowed towards the base, no distinct petiole. — 38
Leaf with a broad blade distinctly marked off from the petiole by an abrupt narrowing. — 39
38 Older branchlets greyish, young branchlets distinctly pubescent, stipules with marginal hairs aggregated into a median tuft, leaf apex smooth, sometimes obscurely pointed (Figs. 19, 48, 49). parviflora
page 55
PLATE 4 40, C. rhamnoides; 41, C. rubra; 42, C. areolata; 43-44, C. rhamnoides (= polymorpha); 45, C. tenuicaulis; 46, C. ciliata; 47, C. rotundifolia, 48, C. parviflora (a) exposed shoot (b) sheltered reversion shoot from same plant, Desert Road; 49, C. parviflora, Kaitaia. (Figures twice natural size.)

PLATE 4
40, C. rhamnoides; 41, C. rubra; 42, C. areolata; 43-44, C. rhamnoides (= polymorpha); 45, C. tenuicaulis; 46, C. ciliata; 47, C. rotundifolia, 48, C. parviflora (a) exposed shoot (b) sheltered reversion shoot from same plant, Desert Road; 49, C. parviflora, Kaitaia. (Figures twice natural size.)

page 56
Older branchlets usually reddish brown, polished, sometimes transversely ridged, young branchlets and stipules hairless or with an evanescent fine velvety pubescence, leaf apex pubescent when young, always blunt (Figs. 1, 32). rigida
39 Petiole usually as long or longer than the leaf blade, blade may be broader than long, leaf apex with a small pubescent projection. — 11
Petiole not usually as long as the leaf blade, leaf apex without a pubescent projection. — 40
40 Leaf blade with only the midrib and a few main secondary veins translucent when held up to the light, takes a long time to shrivel after picking, petiole often has dark margins, stipule slightly sheathing. — 22
Leaf blade thin and translucent with a fine network of veins visible when held up to the light, curls up and shrivels relatively soon after picking, petiole not dark margined, stipule not sheathing. — 41
41 Stipules cup type with a dense hair fringe when young, leaf not more than 8 mm. long, diamond shaped with some deciduous hairs at the apex, branchlets often yellowish (Figs. 17, 59). virescens
Stipules not cupped, almost hairless or with a central hair tuft, leaf usually more than 10 mm. long, apex hairless, branchlets greyish or reddish brown. — 42
42 Leaf smooth to the touch, hairless (see 33), (Figs. 14, 40, 43, 44). rhamnoides
Leaf feels rough or like blotting paper, one surface bearing minute hairs. — 17

Supplementary Information on the Species

C. acerosa

A coastal shrub, often found growing on sand dunes. Branchlets zigzag and trailing with secondaries arching backwards at more than 90°. Fruit oval, translucent, with variable intensity of pale blue surface pigmentation sometimes arranged in longitudinal stripes.

C. antipoda

A southern shrub, upland and montane, in beech forest and scrub. Leaves may bear clusters of short hairs when young (as in C. rugosa and C. brunnea). Fruit oval, translucent, white.

C. arborea

A northern tree. Leaves are tipped by a group of short furry hairs, often carried on a small apical projection. Fruit in dense globular clusters, rounded or slightly elongate, translucent white, sometimes with dark surface colour. Juvenile plants have smaller leaves, often reddish blotched or bordered.

page 57
PLATE 5 50, C. propinqua var. propinqua; 51, C. propinqua var. latiuscula (a-c) exposed shoots (d) sheltered reversion shoot; 52, C. antipoda; 53, C. microcarpa; 54, C. cheesemanii (a) Desert Road (b) Kaimanawa Range; 55, C. rugosa; 56, C. pumila; 57, C. petriei; 58, C. linariifolia; 59, C. virescens. (Figures twice natural size.)

PLATE 5
50, C. propinqua var. propinqua; 51, C. propinqua var. latiuscula (a-c) exposed shoots (d) sheltered reversion shoot; 52, C. antipoda; 53, C. microcarpa; 54, C. cheesemanii (a) Desert Road (b) Kaimanawa Range; 55, C. rugosa; 56, C. pumila; 57, C. petriei; 58, C. linariifolia; 59, C. virescens. (Figures twice natural size.)

page 58

C. areolata

Lowland shrub or small tree, usually in forest. Leaves remain greenish on pressing. Branchlets fastigiate rather than divaricating. Leaf veins may be coloured pink. Fruit globular, dark violet-blue to black.

C. astonii

A southern shrub, montane, in forest or scrub. Leaves taper steadily from apex to base, are often curved and are tipped by a group of short furry hairs. Stipules are white and papery in decay. Fruit globular, scarlet-red.

C. australis

A tree with the largest leaves for Coprosma in New Zealand. Leaves stay fairly green on pressing. Fruit in loose clusters, oblong, orange-red, borne 1-3 per peduncle, the peduncle being swollen just below the fruit.

C. banksii

An undershrub in upland and montane forest. Young stems have a darker transverse pigment band immediately above and below the stipule cup, and a longitudinal pubescent strip below the central denticle. Bark whitish. Leaves stay green on pressing and are tipped by a small group of short furry hairs. Fruit oblong, dark red, borne on a curved peduncle. Hybridises with C. colensoi and C. foetidissima.

C. brunnea

A tangled semi-prostrate shrub with rooting branches. Lowland or more usually upland or montane, usually in shingly situations. Young leaves bear clusters of short hairs. Habit and fruit similar to C. acerosa but blue surface colour of fruit usually more intense, sometimes arrange in longitudinal stripes. See also C. rugosa.

C. cheesemanii

Low or scrambling montane or subalpine shrub found usually in scrub or snowgrass. Fruit globular, orange or scarlet.

Forms (1) An arching and scrambling shrub interlacing with other plants, with linear often yellowish leaves.
(2) A shrub with erect branches and oval green leaves.

C. ciliata

Upland to montane shrub growing in forest and scrub. Exposed leaves may be hairless, all leaves are thin and wither quickly. Fruit globular white (Westland specimen): yellow (Oliver): dark blue to black (Allan): red (Bot. Divn. herbarium).

C. colensoi

An undershrub in upland and montane forest or scrub. Young stems have a darker transverse pigment band immediately above and below the stipule cup, and a longitudinal pubescent strip below the central denticle. Bark whitish. Leaves stay green on pressing and are tipped by a small group of short furry hairs. Fruit oblong, dark red, borne on a curved peduncle. Hybridises with C. banksii and C. foetidissima.

page 59

C. crassifolia

A coastal and lowland shrub, in open vegetation or sometimes in forest. Branchlets stiff, divaricating at right angles, bark brown. Leaves may be hairy below besides having the white bloom. Fruit globular or oblong, translucent white or yellowish.

Forms (1) Erect shrub with slender sometimes pliant branchlets, in forest.
(2) Cushion shrub with thick, stiff branchlets and small semi-fleshy leaves, in coastal habitats.

C. crenulata

A South Island montane and subalpine shrub, found in scrub or boggy places. Branchlets prostrate and trailing. Leaves glossy, blacken on pressing and are tipped by a group of short furry hairs. Young stems have a darker transverse pigment band immediately above and below the stipule, and a longitudinal pubescent groove directly below the central denticle. Fruit oval, orange-red.

× C. cunninghamii

A hybrid shrub exhibiting gradations in habit, foliage and fruit between its two parents, C. robusta and C. propinqua. Fruit oblong, oval or globular, translucent white, pinkish or yellow, sometimes with blue surface stippling especially where injured.

C. depressa

A prostrate shrub, sometimes trailing and rooting, montane or subalpine. Leaf is tipped by a group of white furry hairs. Stipules conspicuously white and papery when old. Fruit globular, scarlet to dark red.

Forms (1) Leaves thick, shining and leathery, almost sessile. Branchlets thick and trailing.
(2) Leaves thinner and dull, abruptly contracted into a petiole. Branchlets fine, plant shrubby.

C. foetidissima

A small tree or shrub, lowland or montane. Dense and compact in exposed situations, but not divaricating. A darker transverse pigment band occurs on young stems immediately below and above the stipule cup. Bark whitish. Leaves blacken on pressing and are tipped by a group of short furry hairs, carried on a small apical projection. Fruit oblong, orange, sometimes translucent. Hybridises with C. banksii and C. colensoi.

× C. kirkii

A variable semi-erect or sprawling ‘waterfall’ shrub known from scattered North Island coastal localities, and occasionally cultivated on banks or rockeries. Fruit oblong, pearly white, sometimes with magenta or purplish surface stippling. A hybrid between C. repens and either C. acerosa or C. propinqua.

C. linariifolia

A shrub or small tree, lowland to montane. Wood yellow. Branchlets dark and fastigiate rather than divaricating. Fruit oblong, translucent white (Oliver), ultimately black (Allan).

page 60

C. lucida

A shrub or tree. Leaves remain green on pressing. Fruit in loose clusters, oval or oblong, orange-yellow to orange, peduncle slightly wider just below the fruit.

C. macrocarpa

A northern coastal shrub or tree. Leaves become black on pressing. Fruit in loose clusters, oblong, orange-red.

C. microcarpa

A lowland to montane shrub, found in beech forest or scrub. Fruit small, globular, translucent white. Exposed plants tend to have yellowish leaves, and have branchlets not forming flat sprays.

C. obconica

Semi-deciduous shrub found only in the Wairoa Gorge, Nelson. Exposed branchlets often bare or with stunted leaves. Leaves shining and slightly wrinkled on the upper surface, pale below with a dark green margin. Fruit obconic, yellowish white.

C. parviflora

A lowland to montane and subalpine shrub growing in forest or scrub. Branchlets more or less divaricating. Leaves sometimes have a yellowish blotch near the base.

Forms (1) Fruit globular, white, sometimes with magenta-purple surface colour. Branchlets divaricating or in flat sprays.
(a) Large-leaved northern form.
(b) Widespread smaller-leaved form with larger leaves occurring sometimes on sheltered (juvenile reversion?) shoots.
(2) Fruit globular, red. Branchlets strongly divaricating, and tend to be recurved at the tip. Found often in bogs.
C. parviflora var. dumosa

C. petriei

A prostrate and mat-forming plant, montane and alpine, in tussock or open places. See also C. brunnea.

Forms (1) Fruit globular, translucent, with blue surface pigmentation or sometimes white (Burrows). Leaf with clusters of short often recurved hairs on both surfaces, stipule margin hairy. C. petriei var. petriei.
(2) Fruit globular, translucent wine red, leaf either hairless or with an occasional long hair on the surface or at the apex, stipule margin smooth and hairless. C. petriei var. atropurpurea

C. propinqua

A shrub or small tree, coastal, lowland or montane, usually in open situations. Branchlets divaricating at right angles. Petiole margin often pinkish or brownish. Stipule bears a single median denticle placed slightly forward of the sheath margin at the tip of the median ridge. Fruit varies from globular translucent with blue surface pigmentation to oblong navy blue or almost black.

page 61
Forms (1) Form found often but not always in swamps, with consistently narrow leaves, brownish polished branchlets and dark fruit. C. propinqua var. propinqua
(2) Form with wider leaves, very short stipule tube, greyish pubescent branchlets and whitish to blue fruits, found from Cook Strait southwards usually on or near the coast. Plants may be semi-prostrate and have larger leaves occurring on sheltered (juvenile reversion?) shoots C. propinqua var. latiuscula
(3) Forms with variation towards × C. cunninghamii.

See also × C. cunninghamii.

C. pseudocuneata

A montane and subalpine shrub, growing in forest, scrub or herbfield. Leaf very glossy and leathery, often curved. Stipules are conspicuous and characteristically dark with a white fringe when young, becoming white and papery in decay. Fruit oval, orange-red to red.

Forms (1) Leaf oval, folded slightly about the midrib.
(2) Leaf narrow almost linear. Found usually in the South Island.
(3) Leaf extremely large and thick. Found on Mt. Egmont.
(C. egmontiana Cockayne)
(4) Leaf small, rounded and yellowish. Plant semi-prostrate with branches ascending towards the tips. This form is found growing in open boggy or windswept places.

C. pumila

A prostrate and mat-forming plant, montane and subalpine, in tussock or herbfield, sometimes near bogs. Leaf conspicuously glossy on both surfaces. Stipule cup persistent. Female flowers large with 3 or 4 styles. Fruit globular, orange-red.

C. repens

A semi-prostrate shrub, erect shrub or small tree from coastal habitats, widely cultivated as a hedge or shelter tree. Some plants are not completely hairless, but have young stems and the lower surface of the leaf covered with fine velvety pubescence. Leaves become black on pressing. Fruit in dense, globular clusters on the peduncle, obovoid and laterally flattened, orange to orange-red.

C. rhamnoides

Shrub, coastal and lowland to montane, in forest or open scrub. Branchlets divaricating at right angles. Leaves stay greenish on pressing, and often have a yellow blotch towards the base. Fruit globular, wine-red to black.

Forms (1) Large-leaved forest undershrub.
(2) Pale-leaved, rigid, reddish-stemmed form in the open.
(3) Form with generally narrower, thinner, faintly shining leaves.
C. polymorpha
page 62

C. rigida

Shrub, lowland to montane in forest or scrub, often in swamps, branchlets divaricating. Domatia wide and shallow. Leaf has a group of deciduous furry hairs at the apex. Fruit obconic with apex indented.

Forms (1) Smaller thick-leaved form, in the open, fruit pearly white or yellow.
(2) Larger thinner-leaved form, in forest, fruit translucent white, pinkish or orange.

C. robusta

A shrub or tree. Leaves blacken on pressing. Fruit in dense clusters, narrowly oval, orange-red.

C. rotundifolia

A shrub or small tree, chiefly lowland, usually in forest or near its margin. Branchlets divaricating. Plants in the open have purplish or bronzy foliage. Fruit broader than long, indented at the apex and very strongly 2 lobed, orange-red, or sometimes whitish (Allan).

C. rubra

Lowland shrub, in forest and scrub. Branchlets divaricating, bark usually red-brown. Leaf thin, sometimes with veins pinkish. Fruit oblong, yellowish or pearly white.

C. rugosa

An upland and montane shrub found usually in scrub. Branchlets divaricating at right angles. Young leaves may bear clusters of short hairs. Fruit oval, translucent, with blue surface markings.

Forms (1) Erect shrub with rigid brownish stems.
(2) Semi-scrambling shrub with dark brownish or purplish slender wiry stems found in inland Otago.
C. intertexta
(See also C. brunnea.)

C. serrulata

A small montane to subalpine shrub found in the South Island. Bark white. Leaves become black on pressing. Fruit oblong, scarlet-red.

C. spathulata

A northern shrub or small tree found in forest. Branchlets fastigiate rather than divaricating. Young stems have a darker transverse pigment band immediately above and below the stipule, and a longitudinal pubescent strip below the central denticle. Leaves sometimes bronze coloured, blotched with red, or with reddish veins, and tipped by a group of short furry hairs, often carried on a small apical projection. Fruit globular or oblong, dark red to black.

C. tenuicaulis

Lowland shrub, in scrub or forest, usually near a swamp. Leaf feels harsh and rough, its margin is slightly crenulate and it often has a yellow blotch near the base. Branchlets dark at the tips and divaricating at right angles. Fruit globular with apex indented, black.

page 63

C. tenuifolia

A North Island shrub or tree. Leaves blacken on pressing. Fruit in small clusters, oval or oblong, pale orange to orange-red.

C. virescens

Deciduous shrub or small tree, lowland to upland, mainly found in the South Island. Branchlets yellowish, divaricating. Cavity of domatia large with a small slot entrance. Leaf has a group of deciduous furry hairs at the apex and sometimes a reddish margin. Stipule cup persistent as a white membranous structure. Fruit globular, whitish. Juvenile branchlets zigzag and interlacing.

C. wallii

A shrub found in a few isolated localities in Canterbury. Resembles C. crassifolia but has smaller leaves less than 1 cm. long. Branchlets extremely rigid and thick, set at right angles to each other. Fruit broader than long, two-lobed, dark red.

I wish to acknowledge the debt I owe to a number of colleagues, fellow botanists, students and friends, and especially Miss L. B. Moore and Mr. N. Potts. I am most grateful to all those who have helped me by collecting fresh specimens, giving me access to herbarium material, sharing their knowledge with me, or by making valuable suggestions and criticisms.

Glossary

  • abscission zone: a separation layer e.g. between leaf and stem or stipule and stem.
  • axil, adj. axillary: the angle between a leaf and the stem.
  • cotyledonary node: the point of attachment of the seed leaves to the stem.
  • crenulations, adj. crenulate: tiny rounded projections or scallops occurring along a margin.
  • denticle: a small toothlike outgrowth of the stipule.
  • domatium: a depression or cavity in a leaf opening to the under-surface.
  • fascicle: a cluster or bunch.
  • fastigiate: having groups of erect almost parallel branches, willow-wand branching.
  • obconic: approximately conical with attachment at the narrow end. teardrop shaped.
  • obovoid: egg-shaped with attachment at the narrow end.
  • peduncle: the stalk of a flower or fruit.
  • petiole: leaf stalk.
  • pit: = domatium.
  • pubescence, adj. pubescent: a covering of short, soft, usually vertical hairs.
  • sessile: without a stalk.page 64
  • stipule: an appendage of the leaf base which derives its venation from that of the leaf.
  • stipule cup; stipule sheath: see Fig. 1 in Part I.
  • truncate: appearing as if cut off abruptly at the apex.
  • whorl: an arrangement of 3 or more lateral organs in a circle surrounding the stem.

References

Allan, H. H. (1924). On the hybridity of Coprosma cunninghamii J. D. Hook. N.Z. Journ. Sci. Tech. 6: 310-18.

—— (1926). The F1 progeny resulting from crossing Coprosma propinqua female with C. robusta male. Genetica 8: 155-60.

—— (1929). The F2 progeny resulting from the crossing of Coprosma propinqua female with C. robusta male. Genetica 11: 335-46.

—— (1931). Significance of Hybridism in the N.Z. flora. A.N.Z.A.A.S. Report 20: 429-77.

—— (1961). The Flora of New Zealand. Vol. 1.

Aston, B. C. (1918). The genus Coprosma as a source of dyes. N.Z. Journ. Sci. Tech. 1: 264-7, 346-51.

Boodle, L. A. (1923). The bacterial nodules of the Rubiaceae. Kew Bull. 9: 346-8.

Briggs, L. H. (1947). Plant products of New Zealand. J. Roy. Soc. N.S.W. 80: 151-77.

Briggs, L. H., et al (1948-54). Chemistry of the Coprosma genus. Parts 1-9. J. Chem. Soc.

Cheeseman, T. F. (1887). On the New Zealand species of Coprosma. T.N.Z.I. 19: 218-52.

—— (1925). Manual of the N.Z. Flora.

Cockayne, L., and Allan, H. H. (1934). An annotated list of groups of wild hybrids in the N.Z. flora. Ann. Bot. 48: 1-55.

Crawford, J. C. (1877). On N.Z. coffee. T.N.Z.I. 9: 545.

McEwan, J. M. (1954). A study of some Coprosma species of the Wellington area. Thesis unpub. V.U.W. library.

Moore, D. M. (1960). Chromosome numbers of flowering plants from Macquarie Island. Botaniska Notiser 113: 185-91.

Oliver, W. R. B. (1935). The genus Coprosma. B. P. Bishop Museum Bulletin 132, Honolulu.

Shirley, J., and Lambert, C. A. (1922). On Coprosma baueri Endlicher. Proc. Roy. Soc. Victoria 35: 19-23.

Sinnott, E. W., and Bailey, I. W. (1914). Nodal anatomy and the morphology of stipules. Amer. J. Bot. 1: 441-53.

Stevenson, G. B. (1953). Bacterial symbiosis in some New Zealand plants. Ann. Bot. N.S. 17: 343-5.

Taylor, A. O. (1960). A biochemical approach to some taxonomic problems in the genus Coprosma. Thesis unpub. V.U.W. library.