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Tuatara: Volume 23, Issue 2, July 1978

Research on Aciphylla — a Progress Report

page 49

Research on Aciphylla — a Progress Report

*

With about 40 species the genus Aciphylla, popularly known as Spaniard or Speargrass, is one of the larger genera of New Zealand flowering plants. It is also one of the most distinctive as some of the species are so spinescent that it is difficult at first sight, even for botanists, to believe that they belong to the Umbelliferae (carrot family).

Much remains to be done in defining and understanding the relationships of the species, but it was thought that it would be useful to report the current state of knowledge as a matter of interest and also in the hope that it might stimulate observations and even perhaps collection of material by others.

In what follows, except where otherwise indicated, the observations are those of the first author. The Chatham Island species will be considered separately after those of the main islands.

The Large Species

On the main islands these are spinescent, mostly short-stipuled, and have narrow elongate inflorescences from a metre to 3 or more metres tall.

It was noted that some species exude a milky juice when cut, others a clear juice. Correlated features are short (4-5 mm), ribbed fruits and long (8-10 mm), winged fruits respectively. The milky juice group comprises A. aurea (figs. 1, 2), A. ferox, and A. horrida; the clear juice group A. squarrosa, A. squarrosa var. flaccida, A. glaucescens, A. subflabellata (fig. 3), A. scott-thomsonii and A. colensoi.

In the former group some populations of A. aurea are distinctive, probably in the genus as a whole, in having the stomata of the leaflets sunken in grooves. The latter group can be subdivided further into species with leaves three or more times pinnate, with the petiolules flattened in a plane at right angles to the lamina. (A. squarrosa, A. squarrosa var. flaccida, A. glaucescens, A. subflabellata); and species with leaves one to two pinnate (lower leaflets only), with the petiolules flattened in the plane of the lamina (A. scott-thomsonii, A. colensoi). page 50
Fig. 1: Aciphylla aurea. Mt. St. Bathans

Fig. 1: Aciphylla aurea. Mt. St. Bathans

(a) North Island

Aciphylla squarrosa occurs along the coasts and on adjacent hills on both sides of Cook Strait. The species has also been recorded on the Volcanic Plateau and the axial ranges, but this appears to be a page 51 distinct form which differs in not having appressed bract segments and having narrower leaf segments, which are often very flexible. Plants of this form from the Ruahines were described as A. squarrosa var. flaccida by Kirk and perhaps the variety should be raised to specific status. Records of A. glaucescens in the North Island are probably of this variety, but A. glaucescens mostly has leaf segments much wider than those of typical A. squarrosa, not narrower. A. colensoi occurs at a number of localities along the axial ranges.

(b) Northern South Island

Aciphylla ferox with its wide leaf segments and ascending to appressed bracts is common on the wet mountains of north-west Nelson. Records from Marlborough are very doubtful.

A. aurea, with narrower leaf segments and spreading bracts, is quite common on the drier Marlborough mountains. With predominantly short stipules this is a different form from the populations further south. It comes near to sea level at Woodside Gorge. The plants here have rather drawn-out flexible leaves, but this may be due to the shady habitat. Small plants similar to A. aurea have been collected at a few localities further to the west — Mt. Cann (see last section this article) and in marble crevices on Mt. Owen and Hoary Head. This may be a distinct variety.

A. glaucescens is abundant in places in north-west Nelson, but also occurs less abundantly in Marlborough in wet sites.

A. subflabellata, common in the eastern South Island, apparently reaches its northern limit in the upper Wairau Valley.

A. colensoi reaches its southern limit in this region.

(c) Central and Southern South Island

The typical form of Aciphylla aurea with long stipules and A. horrida are the large species with milky juice in this region. A. aurea can be common on the drier eastern side of the mountains. A. horrida favours wetter habitats in the west from Arthur Pass southwards. In its typical form it is clearly distinct from A. aurea, being larger with much broader leaf segments in which the stomata are not sunken in grooves. The leaves too are quite a dark green compared with the orangey green of A. aurea. Oliver states that this species often has only two pairs of leaflets per leaf. In the Eyre Mountains we found three pairs of leaflets to be equally common often with secondary pinnules on the lowermost pair. Stipules are more variable than those of typical A. aurea. Between or even within plants stipules may vary from long to short or even be absent.

At some locations of intermediate rainfall we seem to have encountered a problem in distinguishing the species. On Mt. Pisa page 52 and the eastern slopes of the Remarkables we took a common species to be A. aurea, but on closer examination began to have doubts. The plants were similar to A. aurea in size and narrowness of the leaf segments but were a darker green, had variable stipules and did not have the stomata sunken in grooves as did populations of A. aurea further east. This problem will need further investigation.
Fig. 2: Aciphylla aurea. Seed head. Porter's Pass.

Fig. 2: Aciphylla aurea. Seed head. Porter's Pass.

page 53
Fig. 3: Aciphylla subflabellata. Seed head with appressed bract segments forming a kind of cage. Porter's Pass.

Fig. 3: Aciphylla subflabellata. Seed head with appressed bract segments forming a kind of cage. Porter's Pass.

Aciphylla scott-thomsonii, for which an inflorescence 4m high has been recorded, represents the once-pinnate subgroup of those species with clear juice. This species occurs east of the divide, and is abundant in some wetter western localities, but is restricted to locally wet sites further east.

page 54

A. glaucescens and A. subflabellata belong to the several times pinnate subgroup. They are both eastern species, but the latter is like A. aurea in its tolerance of dry sites at low and middle elevations. The relatively short leaves with very compound stipules almost equalling the rest of the lamina are distinctive. An unusual feature is that the centre of the leaf rosette often lies several centimetres below ground level, presumably as a result of root contraction. This may be an adaptation related to dryness of habitat.** At Round Hill near Lake Tekapo there is a form of the species growing in a relatively moist situation near snow tussocks, which is somewhat larger and less glaucous than the typical form. Comparisons in cultivation will be needed to determine the status of this form.

A. glaucescens, as previously noted, requires moister conditions. In northern Southland we encountered plants near a rock outcrop, which had the tall inflorescences and spreading bract segments of A. glaucescens, but the leaf segments were only as wide as those of A. squarrosa.

It may be appropriate to consider the problem of Aciphylla inermis at this point. Oliver (1956) described the species from one herbarium specimen, but it has since been found (singly or in pairs) at three other localities in shrub vegetation near Mt. Cook. The leaves are soft, grey-green and two-pinnate with the petiolules laterally flattened. This suggests an affinity with the A. squarrosa group of the large species, although the inflorescences are only about half a metre tall. However, A. inermis has milky juice and the male inflorescences are broad and these features plus the soft texture raise the possibility, admittedly unlikely, of a relationship with A. dieffenbachii of the Chatham Islands. Unfortunately no female plants have been seen and until some are discovered the status and relationships of the species will be uncertain.

It has been suggested that A. inermis is a hybrid between Aciphylla aurea and Anisotome haastii (Wilson, 1976). If it is a hybrid we find it difficult to envisage the rigid leaved, spinescent A. aurea as one parent.

A few small plants of a soft, grey-leaved, as yet undetermined Aciphylla, reminiscent of A. inermis, have been collected on peaks on Banks Peninsula.

page 55

The Small Species

These are very diverse, but have inflorescences that are mostly less than half a metre high. They can be arranged into five groups, two of which appear to be related to the two groups of the large species.

Group A

The clear juice and relatively long, winged mericarps indicate a relationship with the comparable group of the large species. Inflorescences are narrow and elongate. None of the group is found in the North Island and in the South Island the species are mainly along and west of the main divide.

A. indurata is intermediate in size, having inflorescences up to 1 m tall and with its bright yellow midribs it is rather like a small version of A. colensoi. J. W. D. has collected this species on the Lyell Range, the type locality, and it is also known from other localities in south Nelson and northern Westland.

Three other species of the group also occur on the Lyell Range — A. hookeri, A. townsonii and A. trifoliolata. The first has distinctive short and broad coriaceous primary and secondary leaflets; the second very soft leaves with longer, narrow, almost threadlike leaflets; the third, two or three pairs of long, relatively broad, rigid leaflets.

A. hookeri occurs elsewhere in south and north-west Nelson and north Westland and A. townsonii has a similar range, although probably not extending to north-west Nelson. A. trifoliolata was not seen by J. W. D., but may occur on rocky outcrops at higher elevations. The Lyell Range is the type and at present only locality for A. trifoliolata.

A species of this group has recently been discovered in the south of Stewart Island and it is interesting that it bears some resemblance to the type specimens of A. trifoliolata.

A. crenulata ranges from Arthur Pass to Fiordland. It has simple to once-pinnate, often long and rather flexible leaves. Some segments of the inflorescence bracts extend at right angles to the stem.

A closely related species is A. anomala of south and north-west Nelson. It has less coriaceous leaves and the bract segments are not spreading.

A. takahea of Fiordland may also be related to A. crenulata, but we have little field experience of this species. Its leaves are more compound than those of A. crenulata.

Group B

This group is restricted to the southern third of the South Island in alpine habitats on and east of the divide. Milky juice and short, ribbed mericarps suggest a link with the second group of the large species. Stipules are long, which also accords with some members of the latter group. The leaves are once-pinnate and the inflorescences are narrow.

page 56

Aciphylla kirkii has rigid broad leafllets and is found at high elevations in the western part of the group's range. We have observed it at about 1800 m on rocky outcrops on the Remarkables, where the leaves had a distinct greyish bloom. A. kirkii has also been recorded at lower elevations on Coronet Peak and Ben Lomond, but the plants here grow among snow tussocks and have much longer leaves without any bloom, so their identity is uncertain.

Plants of this group on mountains further east are smaller than A. kirkii and were referred to A. hectori by Oliver. However, our observations suggest that there are two entities involved. On the Old Man Range there is one form at about 1000 m in moist grassy situations. This has ascending leaves with narrow leaflets marked with yellow cross veins. At about 1600 m in alpine tundra is an apparently different form with spreading leaves and wider leaflets lacking cross veins.

In cultivation in J.R.L.'s garden the differences between the two forms if anything increase. The larger form agrees fairly well with typical A. hectori, although plants of the latter from the type locality (Hector's Col, Mt. Aspiring) have acute not rounded leaflets. The other form matches the type of A. poppelwellii, which was merged with A. hectori by Oliver.

Ian Spence of Wendonside, nothern Southland, has observed the two forms on the Garvie Mountains and has also found that their differences increase in cultivation. It has yet to be decided whether the two forms should be treated as varieties or species.

A. verticillata is the last species of this group. It was described by Oliver and is only known from the type specimen from Mt. Kyeburn and a garden grown plant from ‘somewhere in Otago’. (Other records for the species in Otago and Westland are based on mixed sheets of uncertain origin and the leaves identified as A. verticillata match those of A. hectori.) We have visited Mt. Kyeburn and found the A. poppelwellii form, but nothing to match the larger A. verticillata. The answer to this problem may have been found in Ian Spence's garden where a plant of A. poppelwellii from the Garvies growing in a shaded situation had developed unusually long leaves similar to those of A. verticillata and also an inflorescence with the verticillate arrangement of the lower bracts on which the name of the latter was based. As one of the original specimens of A. verticillata was also garden grown in Southland this species may be based on an unusually large specimen of A. poppelwellii.

A frequent feature of this group is variability in numbers of leaflets and stipules within individual plants.

In the preceding groups of large and small species the mericarps usually have fewer than five ribs or wings and have many oil-tubes. In the following groups the mericarps usually have five ribs and few oil-tubes.

page 57

Group C

Here stipules are mostly short and the juice is clear. Some species have broad and others narrow inflorescences.

A. dissecta is the only species of the group in the North Island, being common in the southern Tararuas. It has broad inflorescences, soft, 3-4 pinnate leaves and compound stipules. The one record for the South Island (Boulder Lake) is probably incorrect.

In the northern South Island A. polita has been recorded from the Richmond Range in Marlborough and from the mountains of north-west Nelson. These plants also have broad inflorescences but are smaller than A. dissecta, with 2-3 pinnate leaves and fewer pairs of primary leaflets.

The type locality is in the Richmond Range and the populations here differ from those of north-west Nelson in a number of features. The former have fine, hair-like leaf segments and compound stipules, the latter coarser segments and mostly simple stipules. Within northwest Nelson there is some variation between localities in the width of leaf segments and in the north near Boulder Lake there is a form with particularly coarse segments. Perhaps the north-west Nelson populations should constitute a new species.

The record of A. polita in the Tararuas is probably erroneous.

A. monroi is common on the drier eastern mountains from Marlborough to mid-Canterbury. Records from north-west Nelson and Westland are doubtful. Leaves are once-pinnate, greyish green and the inflorescences are broad.

A. similis (fig. 4) is similar to A. monroi with once-pinnate leaves and broad inflorescences, but it is a larger plant and the leaflets are more numerous, yellow-green, broader and set at quite a wide angle to give the leaves a palm-like appearance. It is found on the main divide, but its range is probably much less than that given by Oliver. The type locality is Arthur Pass and it is found on other mountains in north Canterbury and adjacent Westland.

Oliver's treatment of certain species of this group south of Arthur Pass — A. lyallii, A. similis, A. gracilis, A. flexuosa — is confusing. These all have once-pinnate leaves, but, except for A. similis, narrow inflorescences.

The type locality for A. lyallii is in Fiordland and Oliver regarded the species as extending from there to the mid-Canterbury mountains with a doubtful disjunct record from the St. Arnaud Range in Nelson. It seems to us that the Fiordland populations are different from those further north. Typical A. lyallii has short female flower heads with broad bract sheaths which largely conceal the fruits. The leaves have evident joints at the top of the sheath and the petioles are concave above with acute, often cartilaginous, margins. The plants in populations further north have longer female heads with narrower bract sheaths and visible fruits and in the leaves the sheath joint is obscure and the petiole is flat to convex above with rounded margins. page 58
Fig. 4: Aciphylla similis. Male, left; female, right. Temple Basin.

Fig. 4: Aciphylla similis. Male, left; female, right. Temple Basin.

If it is decided that the two forms are specifically distinct then A. montana Armstrong, based on plants from the Rangitata Mountains, should be reinstated for the extra Fiordland plants. In what follows the name A. montana is used for convenience of reference.

Most records of A. similis from the Southern Alps south of Arthur Pass, often based on sterile material, are probably A. montana, e.g. at Mt. Cook. Apart from the marked difference in their inflorescences, adult, well developed leaves of the two species can also be distinguished. The former has 6-10 pairs of leaflets and the latter 3-4.

page 59

Some records of A. similis from mountains of West Otago and northern Southland east of the main divide are probably of an undescribed species. We have collected this on the Remarkables and there are also herbarium specimens from the Hector Range and the Garvie Mountains. This species has 3-4 pairs of leaflets often widely spreading, a broad male inflorescence and a female inflorescence basically of the broad type ** in which the head is quite small and the few compound umbels almost sessile. It differs then from typical A. similis in having fewer pairs of leaflets and a condensed female inflorescence. Plants from the Eyre Mountains with rather broader leaflets may be of a related form.

We have not studied A. lyallii in Fiordland yet, but as Oliver noted there seem to be several forms there.

Oliver based A. gracilis on two herbarium specimens, the type being from the Kirkliston Range. J. R. L. has examined populations at the type locality and we have both collected similar plants at the Hakataramea Pass and Mt. St. Bathans. This form seems to us close to A. montana, although the leaves do frequently have only two pairs of leaflets so it may warrant varietal status.

A. flexuosa was based on a single herbarium specimen from Mt. Alta. It agrees well with A. montana except that the stipules are unusually long. However sometimes leaves of A. montana have stipules longer than usual and, in addition, there is another herbarium specimen from the type locality collected by the same collector on the same day as the type, in which the stipules are quite short.

The problem will have to be investigated in the field before the status of A. flexuosa can be decided.

We have not yet investigated A. divisa and A. multisecta in the field. A possible new species in this group has recently been discovered on Mt. Alexander in Westland. It is very small, with soft 2-3 pinnate leaves and broad inflorescences. More material is required.

Group D

In this group A. pinnatifida occurs on mountains from Central Otago to Fiordland; A. traillii on Mt. Anglem in northern Stewart Island and A. traillii var. cartilaginea on mountains in southern Stewart Island. They have clear juice, but long stipules and narrow inflorescences in which broad bract sheaths largely obscure the fruits. The laminae are once-pinnate or simple to once-pinnate and are unusual in that the leaflets increase very little in length downwards and may be sub-opposite to alternate. In A. pinnatifida the stipules are also pinnate and very similar to the lamina. In A. traillii the lamina and stipules are often simple, although a few pairs of leaflets are often present in well-grown plants.

page 60

A. pinnatifida usually grows in very wet places and is strongly rhizomatous. A. traillii is not rhizomatous.

The two varieties of A. traillii require more detailed comparison. The var. cartilaginea appears to be a stouter plant with shorter flower heads, wider leaf segments and with more frequent development of leaflets.

Group E

The three species of this group are restricted to the mountains west of Lake Wakatipu and in Fiordland. The stipules are long and simple (sometimes with an accessory pinnule in A. congesta) and the lamina once-pinnate with none of the variation noted for Group B. The juice is milky and inflorescences broad.

A. crosby smithii has coriaceous yellow-orange leaves and forms large cushions. A. congesta and A. spedenii have softer grey-green leaves and often also form cushions. A. spedenii is unusual in having the petiole and intervals between the leaflets very reduced.

Group F

The species in this group also form cushions, which are very dense. The leaves are much smaller than those of Group D, with simple laminae and long stipules, except for A. simplex where stipules are absent. The juice is milky and inflorescences broad and the compound umbels are very compact due to the short peduncles of the simple umbels. Mericarps have not been seen for A. leighii but in the other two species — A. dobsonii and A. simplex — they are unusual in that there are usually no oil tubes in the intervals between the ribs.

All the species grow in rocky places and A. dobsonii (fig. 5) and A. leighii often in screes.

A. dobsonii has the widest distribution, being found at a number of localities near and east of the divide from near Lake Tekapo to North Otago.

A. simplex occurs on eastern mountains in north and central Otago.

A. leighii is only known from the Darran Range in Fiordland and female flowers and fruits have not yet been collected. Allan (1961) suggested that it might be just a reduced form of A. dobsonii, but new material shows it to be quite distinct. The leaves are smaller and paler and the leaf segments are rounded to notched at the tip rather than acute. The species needs fuller investigation.

Chatham Islands

The two species here are A. dieffenbachii and A. traversii. They have inflorescences up to 1 m high so can be regarded as large.

A. dieffenbachii has soft, several times compound leaves with stipules reduced to rounded lobes. Its fruits are distinctive in having mericarps with three and two wings and in being very broad. page 61
Fig. 5: Aciphylla dobsonii. Cushion about 60 cm diameter. Mt. St. Bathans.

Fig. 5: Aciphylla dobsonii. Cushion about 60 cm diameter. Mt. St. Bathans.

The species has sometimes been treated as a distinct genus, Coxella.

A. traversii, with its coriaceous, once-pinnate leaves with short but evident stipules and narrow 3-4 winged mericarps, has been regarded as very distinct from A. dieffenbachii. However closer investigation shows that the two species share a number of features, one of which is peculiar to them. They both have milky juice, broad inflorescences, winged mericarps with fewer than five wings and differ from other species of Aciphylla in having the mericarp veins out towards the tips of the wings instead of at their bases.

Special Features

(a) Tubercles

Some of the species have been described as having serrulate or crenulate leaflets. The latter are not truly toothed, but the appearance is due to the presence of small, more or less hemispherical multicellular protuberances on the strips of lignified tissue near the surface of the leaves and inflorescence axes. These tubercles are most abundant at the margins of leaflets but can also occur on the midribs and sometimes on all the lignified strips.

Not all of the groups of species have tubercles and of those that do some have coarse tubercles (fig. 6), visible to the naked eye, and others fine tubercles (fig. 7), visible only with magnification.

The groups of large species all have coarse tubercules as do groups A and B of the small species. Groups C and E have fine tubercles and the remaining groups no tubercles (fig. 8).

page 62
Fig. 6: Aciphylla takahea. Scanning electron micrograph of ventral leaflet surface. Margin to right. X 50.

Fig. 6: Aciphylla takahea. Scanning electron micrograph of ventral leaflet surface. Margin to right. X 50.

(b) Pulvini

Some species have soft tissue at the front of the base of the petiole extending a little to the back at each side. As a leaf ages this pulvinate tissue enlarges and the lamina curves away from the younger leaves. In some cases the pulvini are very pronounced, particularly in dried specimens, where they become brown and shrunken. In other species they are less clearly defined or absent.

Most of the large species appear to have pulvini, although they are often not very clearly defined morphologically. Most species of Group C of the smaller species have pulvini, sometimes very clearly defined, but in the remaining groups they seem to be absent.

Hybrids

Probable hybrids involving a number of species pairs have been observed in the field and some of these have been described as species. In the usual situation there are more or less uniform populations of two species and an occasional plant of intermediate appearance. Others can probably be added to the following list. None of the suggested hybrids has been investigated experimentally. page 63
Fig. 7: Aciphylla montana. Scanning electron micrograph of dorsal leaflet surface. Margin to right. X 50.

Fig. 7: Aciphylla montana. Scanning electron micrograph of dorsal leaflet surface. Margin to right. X 50.

Fig. 8: Aciphylla pinnatifida. Scanning electron micrograph of dorsal leaflet surface. Margin to right. X 50.

Fig. 8: Aciphylla pinnatifida. Scanning electron micrograph of dorsal leaflet surface. Margin to right. X 50.

page 64

A. aurea x A. crenulata? Mt. Cook. (H. D. Wilson)

A. aurea x A. montana? Mt. Cook. (H. D. Wilson)

A. aurea x A. scott-thomsonii Hakataramea Pass. (J. W. Dawson)

A. aurea x A. subflabellata Rangitata. (J. R. Le Comte)

A. aurea x Anistotome haastii? Mt. Cook, = A. inermis? (H. D. Wilson)

A. aurea x A. poppelwellii Dansey Pass. (J. W. Dawson)

A. colensoi x A. dissecta Mt. Hector; Mt. Holdsworth, = A. intermedia (J. W. Dawson)

A. colensoi x A. polita N.W. Nelson form. Glenroy Area. (J. R. Le Comte)

A. crenulata x Anisotome haastii Mt. Cook. (H. D. Wilson)

A. dissecta x Anisotome aromatica Mt. Hector. (A. P. Druce)

A. divisa x A. montana Mt. Cook. (H. D. Wilson)

A. divisa x Anisotome haastii Mt. Cook. (H. D. Wilson)

A. ferox x A. anomala Mt. Peel, N.W. Nelson. (J. W. Dawson)

A. hookeri x A. townsonii Lyell Range. (J. W. Dawson)

In the last case the probable hybrids were growing in large patches of granite boulders and were so varied that they must include back crosses.

A. hookeri x A. indurata Mt. Bovis. (W. R. B. Oliver)

A. horrida x A. similis Temple Basin, = A. latibracteata. (J. W. Dawson)

A. scott-thomsonii x A. poppelwellii Old Man Range. (J. W. Dawson)

Some backcrossing seems to have been involved here too. Some plants we regard as hybrids have been identified as A. kirkii from this locality.

A. squarrosa var. flaccida x A. dissecta Mt. Holdsworth (J. W. Dawson)

A. squarrosa var. flaccida x A. colensoi Mt. Holdsworth (J. W. Dawson)

Some Notes on Field-Work, Collection and Cultivation
(J. R. Le Comte)

The higher alpine species are noted for their lack of flowers, sometimes for years. This would seem to pose a problem for identification but in fact years of field-work suggest that most of the species can be distinguished easily, even by people with no botanical training, by leaf shape and arrangement alone. I am working on a vegetative key, using the inflorescence only as a ‘back-up’ when flowers are present.

The writer has 31 species growing successfully in the garden, as well as several variants, hybrids, and at least 2 unnamed species. With the exception of A. dobsonii and A. simplex all have proved relatively easy to establish in cultivation. Collected rosettes are page 65 treated as cuttings and root development is rapid. When planted into open ground thick roots develop but whereas in nature there is usually one main root, in the garden there are often several.

A. dobsonii and A. simplex have not been so easy. (A. leighii has not been tried at all.) They usually develop only fine white roots that will not sustain the plant in open ground. However material of A. dobsonii collected from above Lake Tekapo developed a much stronger root system and it is felt that these plants will establish in the garden. This adaptability is probably due to the fact that material collected was from small, young plants only. Because these species usually fail to show strong root development it is obvious that propagation from seed, though slow, offers the best chance of success. Seed collected in the summer of 1976 has germinated and growth will be watched with interest. I have grown many species from seed, but urge patience because often germination does not take place until two winters have elapsed.

Several Aciphylla species have flowered in the garden, and in cases where both sexes were flowering together seed has been produced.

Growing all these species in one uniform garden area is of real scientific value and may yet resolve some of the existing anomalies. For example, if habitat is the cause of observed regional variation this should even out after plants have been growing together for some years in the garden. If genetically divergent forms are involved, however, clearly one would expect them to remain distinct even under the same growing conditions.

I have noted that many high alpine species grow vigorously in a very narrow altitudinal band and that plants growing above or below this are much reduced and unlikely to flower. The leaves of such plants are often not at all characteristic of the species. In the group that has once-pinnate leaves and short, simple stipules, i.e. A. monroi, similis, montana, gracilis, the ‘out of bounds’ plants closely resemble A. monroi, so much so that they have sometimes been incorrectly identified as such. When grown in the garden, however, the plants became ‘normal’ in one season.

An interesting point to ponder is why a species will be stunted when growing 20 metres out of its zone, but quite normal when growing in the garden, about 1,300 metres below its zone!

I have collected A. similis from several areas north of the type locality (Arthur's Pass) and in general terms it can be said that the further north the station, the more reduced the plant. Specimens collected on the Mt. Cann Range (north of Lewis Pass) were so reduced that it was at first thought that the plant was A. monroi until closer examination proved it to be A. similis. After two seasons in the garden these plants now show that they are definitely A. similis, having grown to similar size and habit as plants of that species from other localities. When the Mt. Cann plants were collected we thought page 66 they were possibly a population halfway between A. monroi and A. similis; not hybrids, but part of a cline. The situation has been clarified in the garden.

A year earlier, I collected plants approximately 4 miles north of Mt. Cann in an area just south of the southern boundary of the Nelson Lakes National Park. All these specimens matched A. monroi. Garden cultivation has shown them to be the north-west Nelson form of A. polita (bipinnate), not A. monroi. Presumably they were reduced because of growing out of their usual habitat.

It is known, then, that A. similis extends northwards to a point only some 4 miles from the most southern habitat of the north-west Nelson form of A. polita. The intervening mountains would be interesting places to botanise and Aciphylla specimens from there should be grown on in the garden.

Also on the Mt. Cann Range, amongst hundreds of acres of A. colensoi, I found a small colony of a form of the northern A. aurea. No more than 30 cm high, and without the typical stipules of A. aurea, these plants were growing at over 1,600 metres and may deserve varietal status. Specimens are now well established in the garden and future growth will be watched with interest.

The most common problem in growing Aciphylla seems to be collar rot but this condition is not very prevalent in the author's well-drained mid-Canterbury garden. The most troublesome ‘beasties’ are mealy bugs that live and multiply alarmingly between the leaf sheaths, slowly killing the plant. Their presence is evident by the white ‘meal’ on the lower part of the leaves and a systemic spray should be used, thoroughly drenching the plant.

In the revision of the genus, the emphasis is on field-work and both authors have attempted to visit as many mountains as possible. Middle-age and available time place certain restrictions upon such plans.

We have had wonderful assistance from a West Coast helicopter firm which has enabled J.R.L. to visit many otherwise inaccessible areas, including many isolated peaks above bushline.

Every summer swarms of vigorous trampers and climbers are loose in the mountains; if even a little of this energy could be harnessed for botanical purposes, what a full and complete revision could be made. TRAMPERS please note: no offer of assistance will be refused.

Acknowledgements

We are grateful to Dr. L. B. Moore for helpful discussions and advice; to Hugh Wilson for comments on the manuscript; to the curators of the herbaria at Otago University, Botany Division, D.S.I.R., Canterbury University, the National Museum and Auckland Museum for access to and loan of specimens; and to Alpine Enterprises Ltd, for transport to a number of mountain tops.

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References

Allan, H. H., 1961: Flora of New Zealand. Vol. I. Government Printer, Wellington.

Oliver, W. R. B., 1956: The Genus Aciphylla. Trans. Roy. Soc. N.Z. 84: 1-18.

Wilson, H. D., 1976: Vegetation of Mount Cook National Park, New Zealand. National Parks Authority, Scientific Series, Number 1. Wellington.

* Botany Department, Victoria University of Wellington

No. 2 R.D., Ashburton

** J.R.L. recently repotted more than 100 two-year seedlings of A. subflabellata and the crown of each was well below the surface even though the mixture was always moist. Also, most of the seedlings had sent out a long ‘questing’ root from 60 cm to over a metre long. This is by far the most vigorous root development encountered so far.

Hybrids in many genera show reduced pollen fertility as judged by the percentage of shrunken or empty pollen grains. The pollen of a few Aciphyllas, including A. inermis, has been examined and the percentage sterilities were — A. lyallii, 1%; A. crenulata, 4%; A. inermis (Type), 4%; A. latibracteata (Type. Suspected hybrid), 31%; A. scott-thomsonii x A. poppelwellii (Old Man Range), 78%.

** As well as being broader, broad inflorescences also differ from narrow in usually having fewer compound umbels and in the terminal umbel being the largest.