Immediately above this is a distinct belt of Xiphophora — beaches (Station 4) show a quite different zonation. On a peculiarly long and rather slender form which is either these platforms Hormosira banksii is very well developed a distinct species or an (marked) ecological variant. and Ulva lactuca is common. The pink basal structures Interrupting this brown belt in very, exposed places, as of Corallinas axe. abundant in more exposed places and on points and islets, are pure patches of the red algae, the erect calcareous thallus of this species frequently Pachymenia himantophora. dominates in the mtertidal pools. On shaded sides of the reefs Codium adhaerens is very common, while on exposed THE EAST COAST (STATION 2) rock faces (especially above the Xiphophora belt) Apophloea An interesting feature of the moderately exposed situations sinclairii is abundant. The oyster Saxostrea also occurs existing on the East Coast is the presence of Carpophyllum on these upper rocks of the supra-littoral fringe. Nerita maschalocarpum and C. elongatum growing together. The is conspicuous at the highest levels immediately in front C. elongatum dominates in the 'surge region' (lower-mid- of the narrow, moderately steep, shingle beach. littoral and upper infra-littoral fringe) whilst C. maschalo- carpum dominates below low tide mark in the infra- In conclusion it can be said that the zonation pattern littoral fringe proper. The presence of C. elongatum on of the Chickens appears to corrsepond closely with that the East Coast was at first puzzling, as this coastline is recognised so far by observers on other parts of the north• sheltered from the north by a low' reef and from the east east coastline of . (See Trevarthen 1954 and by another island of the group. The C. elongatum belt Dellow 1955.) was largely explained when local boatmen pointed out that although the prevailing winds come from the south• References : west, the stronger gales come from the south-east, to which Dellow, V., 1955: 'Marine Algae Ecology of the Hauraki quarter this coastline is very exposed. Gulf, N.Z.' Trans Royal Soc. N.Z. Vol. 83 : 1, pp. 1-91. THE SOUTH COAST (STATION 3) Trevarthen, C. B., 1954: 'Features of Marine Ecology of On the headlands a' rather similar 'exposed coast' pattern Little Barrier, Mayor and Hen Islands.' Tane, Vol. 6, is developed, but the broad midlittoral platforms on the pp. 34-60.

EARTHWORMS FROM WHAKAHAU AND MAROTIRI ISLANDS

By MARGARET M. ESSON

The earthworms, discussed below, collected in August found in the B horizon of grey brow'n crumbly clay. 1955, were kindly identified by Mr K. E. Lee of the S. gigantea was also found near the surface of the loose Soil Bureau. soil of the stream bed where surface litter was absent and where Metrosideros and Olea apetala were dominant. MAROTIRI ISLAND This species was also found near the Waipawa Stream of On Marotiri earthworms were predominantly large sub-soil Little Barrier in 1952. species of importance in the formation of soils. Those on Megascolides irregularis was found in the loose crumbly the Marotiri were found to be mainly of skeletal nature, clap topsoil of the upper and lower streams at stream or in the immature and semi-mature stages of develop• level under Metrosideros, Olea and Maeropiper and has ment. been found on Little Barrier near Waipawa Stream and Hoplochaetina subtiles, 5-6in. long, was found 9in. on Pohutukawa flat. deep, in the crumbly clay of the B horizon of the steep slopes in the vicinity of the petrel burrows, where surface Spenceriella shakespeari was commonly found in the litter was absent (spiders and insect larvae were present same habitat. It occurs widely on Little Barrier. in the soil). The vegetation included Metrosideros, Rhododrilus sp. was also found in this habitat. Mr Lee Leptospermum, Suttonia, Dysoxylum, Br achy glottis and notes that this may be R. sutherlandi which he described Asplenium. This species was not collected in 1952 on from Whangarei in Trans. Roy. Soc. Little Barrier or Mayor Islands. Spenceriella gigantea was found on the ridge 18in. deep WHAKAHAU in the flecked yellow brown crumbly clay of the C hori• A Megascolides sp. was collected by E. N. Milligan zon. Leptospermum was dominant; Suttonia, Pittosporum among litter under Metrosideros, Leptospermum, etc. Mr and Nothopanax were present and native grass and a Lee notes that these two small juvenile forms were deep mull litter covered the ground. No worms were probably M. maorica which was also collected on Little found in the litter, but smaller unidentified worms were Barrier in 1952.

15 AN ACCOUNT OF SINCLAIRII (PUKANUI) ON MAROTIRI ISLAND

By I. A. E. ATKINSON

Though Meryta sinclairii with its enormous leaves and Because no counts of juvenile were made on the regularly shaped habit is well known as an ornamental coastal cliffs, the figure for the younger age groups is in in Auckland gardens, few people have had the all probability much too low. When allowance is made opportunity to see it growing in its native habitat. The for these facts it appears that regeneration of seedling Three Kings and Hen and Chickens island groups are and sapling stages has been, and still is, at least suffici• its only places of natural occurrence. ent to maintain the numbers of the adult plant. Evidence In what sort of situations does Meryta occur and is it will later be brought forward to show that the Meryta increasing, decreasing or merely maintaining its numbers population of Marotiri is actually increasing. on these islands? Is there any explanation for the pecu• liarly discontinuous distribution of this plant? These THE COASTAL CLIFF HABITAT: questions are discussed in the following account which Meryta is frequent, its bright green foliage standing out summarises observations made on Meryta during a clearly against the sombre green of pohutukawa (Metro• week's visit to Marotiri (Big Chicken Island) in August, sideros excelsa). Along the northern and eastern coasts 1955. For a full account of the island's vegetation refer• it usually occurs singly but no plants were observed ence should be made to the paper in this volume by around the cliffs of the north-western portion of the C. A. Percy. island. Stands or groves have been established at several points along the southern coast, the largest of which is DISTRIBUTION: situated at Koputotara Point and numbers approximately Meryta is present on all islands of the Chicken group and 120 plants. Since this grove is typical of the way in reaches its greatest abundance on Marotiri where three which Meryta occurs on the coast it is described more main types of habitat may be recognised: fully. 1. Ridge including the upper half of the valley wall. The site is a south-facing consolidated talus slide 2. Valley including the lower half of the valley wall. which falls steeply to the sea and is flanked on both sides 3. Coastal cliff including debris slides and rocky out• by vertical cliffs. Both these cliffs and the slopes behind crops. are dominated by pohutukawa, but on the talus slide Total counts of Meryta plants observed in each of there is complete dominance by Meryta. The closely these habitats are summarised in Table 1, while the spaced trees, up to 17 inches in diameter, form an actual distribution is indicated by the figures on the uneven closed canopy at a height of 25 feet, below accompanying map (See fig. 1). which there are only a few Astelia plants. Seedlings and TABLE. I saplings of Meryta are restricted to the perimeter of the Habitat No. of plants observed grove which is apparently even-aged. Coastal cliff 286 Buddie (1948) has described larger but otherwise simi• Valley 203 lar groves on South West and North East Islands of the Ridge 87 Three Kings group. On the coastal cliffs Meryta usually grows on unstable Total: 576 debris material rather than rocky outcrops; a preference On the sea-cliffs these figures are counts of adult which may be related to the structure of the root plants only, while inland they are totals of juvenile and system. All specimens examined had strongly developed adults counted along traverses of valley-bottoms and tap-roots as well as a system of superficial lateral roots. ridge-tops. Although a wide coverage of the island was A deeply penetrating tap root would be suitable for made, many plants will have been missed. Nevertheless colonisation of unstable talus material though possibly a the total Meryta population of the island would probably disadvantage in establishment on rock surfaces. not exceed 1,000 plants. Reference to the map should enable future observers to follow any major numerical THE RIDGE HABITAT: fluctuations which may take place. On the kanuka (Leptospermum ericoides) dominated ridges, Meryta plants, both juvenile and adult, are widely POPULATION ANALYSIS: scattered. Along the western ridges no plants were ob• Though varying according to environmental conditions, served but on other ridge-tops, fruiting adult plants heights may be taken as a reasonable index of age. were seen up to 480 feet above sea-level. Juvenile plants Using a camera range-finder, 378 plants were measured, were confined to areas of Leptospermum scrub in which which when classed into height groups give an indication other species, particularly kohe-kohe (Dysoxylum specta- of the age group distribution of the population (See bile) were regenerating. fig. 2). On the south-west ridge leading towards Koputotara

16 Point, there is a small group of ten Meryta trees, up to It can be seen that Meryta is well established in each 30 feet high, which with some seedlings and saplings, of the three main types of habitat on the island. Never• are growing on the site of an old Maori pa. This associa• theless, apart from a few localised areas, it does not tion of Meryta with sites of Maori occupation has also dominate the island's vegetation as is the case with the been observed by Buddie (1948) on the Three Kings and less modified of the Three Kings Islands (Baylis, 1948; Cochrane (1954) on Hen Island. Buddie, 1948). Some of the factors limiting its spread on Marotiri will therefore be discussed. THE VALLEY HABITAT: Small groves of Meryta plants are often present in the FACTORS LIMITING THE SPREAD OF MERYTA valley mouths while further up the valley, seedlings and SINCLAIRII ON MAROTIRI: saplings as well as a few adults are found. Juvenile plants are particularly concentrated at the junctions of 1. Salt Spray stream-courses. A gradient of decreasing number of The effects of wind-carried salt spray are seen in the plants with increasing altitude and distance from the stunted growth-form of some of the coastal plants. A coast is typical of several of the valleys. Other valleys gradient of decreasing height with increasing proximity contain very few plants while 'North-east Valley' has to the sea can be clearly seen in the large grove de• only two Meryta plants growing at its mouth. scribed above, where the canopy is reduced from 25 feet

17 to little more than 8 feet in height. On the north coast greater abundance of Meryta in the valleys. no plants occur below 50 feet altitude, but on the more 4. Light sheltered parts of the south and east coasts, Meryta Meryta plants \ often grow in canopy gaps caused by descends to just above the splash zone where, on the sea• fallen trees. Healthy plants, were also growing in the ward side of the plant, salt-spray effects can be seen much reduced light conditions of some of the valley in the brownish burn patterns and thickening of the bottoms. Millener (1947) has also remarked on the shade- leaves. The complete absence of Meryta around the tolerance of Meryta. Counts were made of the number of north-western coast-line cannot be due to exposure since Meryta plants under the various types of canopy (See Meryta is growing in very exposed northerly aspect situ• Table II). The total counts in the right-hand column ations on the West King, Three Kings group (Cheese- are largely a reflection of the relative areas which the man, 1890; Buddie, 1948). different types of canopy occupy on the island. The re• 2. Soil Moisture maining figures are more significant. With the exception The soils of Marotiri are clay loams weathered from of pohutukawa canopies and full light conditions, there greywacke and are not deep, except in the valley bot• is a marked reduction of Meryta in the taller height toms. The greater abundance of Meryta in the valleys groups. These figures cannot be explained by assuming as compared to the better illuminated ridge-tops may be that above 10 or 15 foot Meryta is growing in full light; partly a result of the increased available moisture of the the forest canopy is usually 30 feet or more in height. valley sites. This might explain the gradient of decreas• It must also be pointed out that the higher figures for ing Meryta abundance as one progresses higher up the the 1-5 foot group are not a result of counting numerous Valleys, but factors of seed dispersal are probably also first-year seedlings. Of this group 56 per cent (76 plants) involved. That Meryta can tolerate low moisture condi• were between 3 feet and 5 feet in height, i.e., at least tions is shown by its dominance on excessively drained two years old (See growth rates). ciliff sites. Most of the plants belonging to this group were well 3. Seed Dispersal established saplings under a closed forest cover. Only 8 Many Meryta plants probably establish where seeds fall plants less than 12 inches high were observed. from the parent tree, which, by itself, would mean a very There are only two possible explanations accounting slow rate of dispersal. Buddie (1948), Baylis (1948, 1951) for the lack of representation of the taller height groups: and Turbott and Bull (1954) refer to the eating of 1. A high mortality rate of saplings would prevent Meryta fruit by red-billed gulls. They state that seeds of many plants from reaching the older age groups. Meryta could have been transferred by this means from 2. Widespread regeneration of Meryta under a closed South West Island or North East Island to Great Island, forest canopy has only begun fairly recently. where this species has become re-established. According 5. Mortality to Mr. E. G. Turbott (pers. comm.) this explanation A total of twelve dead or dying plants was counted, probably does not fully account for the appearance of eleven of which had been adult trees more than 20 feet Meryta on Great Island. On Marotiri other birds may high, while the twelfth was a 10 foot sapling. Four of feed from seed trees round the coast. Birds flying inland the dying plants possessed brownish blotchings on the would tend to keep to the forest of the valleys with its leaves and were exuding gum from the dying shoots. greater cover and possibly greater attractiveness to fruit- These symptoms are similar to those described by Miss eating species. This may be a contributing factor to the J. Hastings (1949) for a fungus disease of Meryta

TABLE II Type of Canopy Ht. groups of Meryta plants 1-5' 6-10' 11-15 16-20' >20' Total Metrosideros excelsa .. 10 17 16 28 47 118 Full light (e.g. canopy gaps) . . .. 15 7 3 13 41 79 Metrosideros excelsa over Dysoxylum spectabile ..34 8 0 0 0 42 Dysoxylum spectabile .. 20 6 6 0 0 32 Olea apetala ...... 10 9 3 2 0 24 Corynocarpus laevigata .. 15 3 2 1 0 21 Meryta sinclairii .. 8 7 4 0 1 20 Leptospermum ericoides 3 3 3 2 1 12 Vitex lucens .. 7 2 1 1 0 11 Metrosideros excelsa over Corynocarpus laevigata .. 3 1 2 0 0 6 Suttonia australis ...... 3 1 1 0 0 5 Hoheria populnea ...... 2 1 0 0 0 3 Phormium tenax .. 2 0 0 0 0 2 Pittosporumcrassifolium ...... 2 0 0 0 0 2 Pisonia brunoniana ...... 1 0 0 0 0 11 Totals 135 65 41 47 90 378

18 thought to be caused by the fusarium Hypmyces haema- (1914) mentions a Meryta tree in his garden which grew tococcus. Miss Hastings examined root material of a to a height of 20 feet in less than 10 years. healthy seedling and of a dying adult brought back from These measurements indicate that Meryta has an ex• the island. She could find no evidence of infection in ceptionally high growth rate although its adult size is the seedling but the adult material contained fungal limited. We can safely say that a 5 foot sapling growing hyphae, identification of which was not possible due to under a M. excelsa/D. spectabile canopy cannot be older the absence of fructifications. than 25 years and is probably much younger. The figures It is possible that this fungus has killed many trees in of Table I can thus be interpreted as showing a steadily the past since Mr F. Holman (pers. comm.) states that increasing influx of Meryta seedlings over the last 40 when he visited Hen Island in 1898 he saw many dead years. Meryta trees. It seems doubtful, however, whether this 7. Animals fungus attacks juvenile plants. Goats prevented regeneration of Meryta on Great Island, A small percentage of saplings had been severely Three Kings group, until their removal in 1946 (Baylis, chewed in the basal parts of the older leaves, which Mr 1948). J. S. Edwards suggested was possibly due to wetas. Mr E. Wright (personal communication states that Signs of other types of invertebrate damage were noted cattle were released on Marotiri during the early part in many plants, both juvenile and adult, but there was of the century. He last saw cattle on the island in 1924. no indication that any of these attacks would be suffici• Cranwell and Moore (1935) record that some years ent to cause high mortality. ago a few bullocks swam ashore from a scow in heavy Widespread deaths after prolonged drought seem un• weather off the biggest Chicken, causing much disturb• likely in view of the deep valley soils and the tolerance ance till their death. by Meryta of xeric conditions round the coast. The family to which Meryta belongs, the , Though we cannot dismiss the possibility that many is very palatable (Aston, 1911) and it is highly probable juvenile Meryta plants have died due to some unknown that Meryta is itself palatable to stock. If this is the case cause, it seems more probable that an influx of seedlings then the recent influx of seedlings already discussed and saplings in the valleys and to a lesser extent on the would at least be partly explained. However, other ridges has begun relatively recently. factors such as the dioecious habit, reproductive capacity 6. Growth Rates and methods of seed dispersal must also be invoked if we Miss V. J. Howie (1941) has made a detailed study of are to account for the rather slow rate of regeneration. the morphology and anatomy of Meryta. She found that Mr A. .H. Pickmere (personal communication) has growth was confined to characteristic bursts of activity noted chewed leaves and scratches on the bark of some with intervening quiescent periods. Such bursts, from two trees which have since recovered. This damage he be• to four per annum, might take place at any time during lieves was caused by native rats (Rattus exulans) which the year including winter. are common on the island. No scratchings or chewings Thirteen saplings and seedlings were encountered on which could be attributed to rats were seen during the the island which were undergoing bursts of growth, and period of observation a further 35 plants had recently completed a period of During her 1933 visit to the Hen and Chickens Island, activity. The extension growth of 34 of these plants was Miss L. B. Moore (pers. comm.) noticed many damaged measured and growth rates under full light and forest Meryta berries lying on the forest floor. This, she be• canopy can be compared (See Table III). lieves, was probably caused by Kakas (Nestor meridion- As is to be expected, the growth rate under a forest alis) which were common in the area at the time. Cran• canopy is considerably retarded but is nevertheless well and Moore (1935) attribute the death of Meryta appreciable. Other bursts of growth would be at least plants, on one of the Chicken slands, to the roosting of as great as the winter measurements recorded here. starlings migrating from the mainland. Growth rate measurements made on a number of sap• 8. Fires lings in Auckland gardens show that Meryta can grow Percy (this volume) has reached the conclusion that little at rates up to 2 feet per annum during the first three if any of the vegetation of Marotiri can be regarded as years of its life. Kirk (1889) records a Meryta tree which primary. Fires and cutting of timber for pa stockades grew to a height of 25 feet in 20 years and Cheeseman almost certainly took place in pre-European times with

TABLE III

Light conditions No. of measurements Range Mean with standard error of the mean

Full light 14 2-7" 4-2 ± 0-56" M. excelsa over D. spectabile 13 /2-2-5" 1-3 ± 0-15" Dysoxylum spectabile 7 1-3-5" 1-9 ± 0-3"

19 consequent modification of the primeval vegetation. Such 2. Meryta plants are killed by disease on Marotiri before clearing of the vegetation cover would have created fresh reaching larger diameters. sites suitable for colonization and Meryta would have 3. The present Meryta population of Marotiri has not established if seed were available and conditions for been established for any great length of time. germination suitable. HISTORICAL OBSERVATIONS OF MERYTA Judging by the present distribution of Meryta on ON MAROTIRI ISLAND: Marotiri, one or both of these conditions was not satis• The most recently published mention of Meryta on the fied, since there are no extensive groves of Meryta either Chicken islands is that of Cranwell and Moore (1935) on Marotiri, or any of the other Chickens, comparable who remark: 'abundant to locally dominant'. to the 3-4 acre stands mentioned by Buddie (1948) on Cheeseman (1890) states: 'Mr Reischek, who landed the outlying Three Kings Islands. several times on the Chickens while pursueing his The pattern of Meryta distribution on Marotiri has ornithological researches, also saw the tree, and has in• been partially modified by fires during the last hundred formed me that about twenty or thirty are all that exist years. Cheeseman (1890) records that recent fires had on the group. He observed, however, a solitary specimen destroyed several Meryta trees on the Chicken Islands. on the north side of the Hen Island.' In 1908, when the s.s. Muritai was wrecked on the Reischek, the German naturalist, visited the Chickens Western Chick, the crew came ashore on Marotiri and in December 1880, but Cheeseman himself had visited lit a fire which burnt the vegetation of West Bay (Mr the islands in the eighteen seventies when he 'saw 13 F. Holman, pers. comm.). At present there are two adult old plants and a few seedlings'. Meryta plants in the area although an 18-inch diameter The earliest account we have of Meryta is that of dead tree was also discovered. A total of 14 juveniles was T. Kirk (1869) who visited the Chicken islands and counted, mostly in canopy gaps. Dr W. R. B. Oliver's writes: 'Not more than eight plants were observed, of photograph of West Bay, taken in 1924, shows that at which six were in various stages of flower and fruit.' that time there were at least three Meryta plants in the Kirk (1889) mentioning this trip in his Forest Flora canopy. Large-scale regeneration of Meryta in this area remarks: 'The plants found at that visit were confined to could not have taken place after the 1908 fire. old Palaeozoic rocks on one of the small islands of the Mr E. Wright (pers. comm.) states that there have group. Mr Robert Mair has recently discovered a few been no fires on Marotiri during the past 40 years. plants on another island and Mr T. F. Cheeseman has In the foregoing discussion the effect of a number of found a single plant on the largest island, which is en• factors influencing the spread of Meryta has been tirely volcanic'. assessed. The situation has probably been over-simplified, Perhaps the earliest mention of Meryta occurs in a but allowing for the past occurrence of fires and loss of letter written by William Colenso to Dr Sinclair in 1839 adult plants by disease, there are still large areas of the (Bagnall and Petersen, 1948). Colenso writes: 'Have island where it is difficult to account for the absence of heard from good native authority of several strange adult and sometimes juvenile plants. In these sites, ex• plants, trees growing on the islets (only) on the E. Coast posure to salt-spray, soil moisture and light conditions, of N.Zd.—one, has very large leaves large enough (so though undoubtedly affecting the rate of growth, cannot say natives) to wrap a codfish in! This summer (D.V.) I be regarded as responsible for the absence of Meryta. shall be in the neighbourhood and then I'll get it.' The evidence we have indicates that the Meryta popula• The mention of only a single plant on Hen Island is tion of Marotiri is increasing. The rate of spread has particularly interesting. According to Mr F. Holman been slow, perhaps, due to methods of seed dispersal and (pers. comm.), Meryta was as abundant on Hen Island in the reproductive capacity of the plant. It was almost 1898 as it is to-day. The two observations, made 18 years certainly further retarded in its early stages by grazing apart, may not be incompatible in view of the high animals. Furthermore, the slow rate of spread and the growth rate of Meryta already discussed. lack of extensive Mertya stands, which one might have It is not possible to say for certain how thoroughly expected to have established after abandonment of culti• these islands were searched for Meryta by the observers vation areas and pa sites by the Maori, suggests that cited above. The only safe deduction which can be the initial parent population was a small one. drawn from these observations is that Meryta was far The largest living tree observed measured 17 inches in less abundant on the Hen and Chickens in the early trunk diameter, but most adult trees ranged between part of the nineteenth century than it is to-day. 6 and 10 inches in diameter. This is much smaller than Marotiri was once populated by the Maori, as is the 30-36-inch diameter specimens noted by Buddie shown by the numerous pa sites and abandoned cultiva• (1948) on the Three Kings and suggests three possi• tion areas to be found. Fires in pre-European times have bilities: clearly taken place on both the Hen and the Chickens 1. Climatic and edaphic conditions on Marotiri are not islands. It is possible that during this period the numbers as suitable for the growth of Meryta as the conditions of Meryta were greatly reduced and increase in numbers on the Three Kings. Comparative growth rate has taken place only since the Maori left in 1821 measurements should be made to clarify this point. (Cranwell and Moore, 1935). This explanation is not alto-

20 gether satisfactory since the Three Kings Islands, which Meryta reached New Zealand in the early Tertiary at a were also settled by the Maori, are in many places time when there were northward connections either by dominated by Meryta (Buddie, 1948). In his account of a continuous land bridge or a series of closely spaced North East Island, Major Buddie says: 'The greater part islands. The inability of Meryta to cross large stretches of the puka grove, perhaps three or four acres, has been of sea would also indicate that the Three Kings Islands cleared of stones and walled and terraced by Maoris: in have been isolated for a very long time as has been some cases the walls are still standing, but mostly are postulated by Oliver (1948). now represented by piles and lines of stones, through That Meryta reached New Zealand via the Three which pukas up to 3 feet in diameter and 30 feet in Kings route seems probable. The problem, however, is height are now growing: these have the appearance of still before us. The Hen and Chickens Islands are separ• having grown since the date of the last Maori occupa• ated from the Three Kings by a distance of approxi• tion.' mately 180 miles. It is also possible that the numbers of Meryta on the The lowering of sea-levels which took place during the Hen and Chickens have been greatly reduced in the Pleistocene (Brothers, 1954) would presumably have past by fungus disease. There have been no reports of placed the Hen and Chickens in connection with the Meryta plants dying in this way on the Three Kings. mainland several times. During the last glaciation, with A third possibility is that Meryta was never present its climax some 30,000 years ago, the coastline was in large numbers on the Hen and Chickens at any time. probably many miles eastward of its present position, possibly somewhere about the present forty-fathom mark (Searle, 1956). Study of the Admiralty charts would sug• • DISCUSSION: gest possible land connections with Little Barrier, Great Meryta sinclairii occurs naturally only on the Three Barrier and Coromandel peninsula as well as with the Kings and Hen and Chickens islands. Plant distribution mainland at this time. Ocean depths off the North Cape arguments based on absences are liable to be dangerous. indicate that the Three Kings islands remained in iso• Nevertheless Meryta is such a conspicuous plant that it lation. If Meryta was growing on the Hen and Chickens seems doubtful whether it will be. recorded from any at this time, one might have expected it to have extended additional localities. (The Poor Knights Islands and the its range. Whangarei Heads would be the most likely places in Thus the present distribution of Meryta does not ap• which to search.) There may therefore be some justifica• pear to be readily explicable in terms of past climates tion for attempting to discuss the problem of its dis• or previous land connections. It is possible that some continuous distribution; if only for the purpose of bring• disease has wiped out Meryta in localities where it for• ing this problem to notice. merly grew, leaving the plants on the Three Kings and Meryta is the only plant in the Flora with this par• Hen and Chickens islands as the only survivors. ticular distribution. The climate of Auckland and North •Nevertheless it seems worth while to suggest that the Auckland is clearly suitable, as is shown by the growth present distribution pattern of Meryta may be a second• of ornamental plants in gardens. In Auckland, Meryta ary one, i.e. Meryta has reached the Hen and Chickens seedlings often establish close to parent trees and grow from the Three Kings by the agency of man—in this to maturity. Meryta is intolerant of frosts (Howie, 1941) case the Maori. It could possibly have been a case of and it is possible that temperature has been a limiting chance transport but it seems more likely that the Maori: factor to its range in the past. The first possibility, then, actually transplanted it from the Three Kings to the is that Meryta was once on the mainland but disappeared Hen and Chickens since there is definite evidence that with, the onset of an unfavourable climate. The present they planted Meryta plants in other places. Such a rare distribution would then represent places where Meryta and unusual plant was probably a cherished and jeal• had survived in a more favourable climate. The difficulty ously guarded possession of the tribe in whose territory with this hypothesis is to account for the absence of it grew. Meryta from other apparently equally favourable locali• The original type description for the species was made ties, e.g. Little Barrier Island, Moko Hinau Islands, Poor from a solitary tree growing at the head of Whangaruru Knights Islands and sheltered parts of the mainland Harbour. This plant the Maori claimed had been coast. brought from the Poor Knights Islands. It was strictly Oliver (1953) considers Meryta to be a Tertiary immi• tapu and surrounded by a high fence (Kirk, 1839; grant from the Pacific where the genus is represented Cheeseman, 1890). When the Maori discovered that by 24 other species (Cheeseman, 1925). At present the Mr Robert Mair had taken fruits from this tree, they 38 mile gap between the Three Kings and Cape Reinga cut it down (Kirk, 1889). is a barrier to migration. Carriage by wind, sea or birds Kirk (1869) records that: 'The Maoris at Ohora stated is apparently ineffective over this distance, though the that they, some years back, planted a young tree on one 3 mile and 1 mile gaps between South-West King, Great of the Fanal Islands, which is still living although it King and North-East King islands were not barriers to has grown but little.' This story is almost certainly au• migration of Meryta after goats had been removed from thentic since Miss Noelle McDonald, who visited Fanal the Great King (Baylis, 1951). This may indicate that Island (Moko Hinau group) during 1954, found a Meryta

21 tree, some 15-20 feet in height, growing in a sheltered capacity, its germination requirements and the fungus bushed valley towards the centre of the island. disease studied by Hastings (1948). Perhaps there is no final answer to this problem. Of the possibilities discussed it appears that reduction of ACKNOWLEDGEMENTS: numbers by disease or transplanting by the Maori could I wish to thank Miss L. B. Moore, Mr E. G. Turbott and best explain the present distribution of Meryta sinclairii. Dr L. H. Millener, each of whom read the manuscript It is hoped that this article will encourage further of this paper and made valuable criticisms and sugges• work on the biology of this fascinating plant. In particu• tions. I would also like to thank other members of the lar we need to have more information on its methods of club who assisted me with many relevant observations seed dispersal, its breeding system and reproductive whilst on Marotiri.

REFERENCES

Aston, B. C, 1911. Some effects of imported animals on the Hastings, J. M., 1949. A Fungal Disease of Meryta sinclairii. Un• indigenous vegetation Proc. N.Z. Inst. Pt. 1. pp. 19-24. published thesis. Auckland University College.

Bagnall, A. G. and G. C. Petersen, 1948. William Colenso, p. Howie, V. J., 1941. Some Observations on Meryta sinclairii. Un• 83. A. H. and A. W. Reed, Wgtn. published thesis. Auckland University College.

Baylis, G. T. S., 1948. Vegetation of Great Island, Three Kings Kirk, T., 1869. An Account of the Puka. Trans. N.Z. Inst. Vol. Group. Rec. Auck. Inst. Mus. Vol. 3, pp. 239-252. 2, pp. 100-102.

Baylis, G. T. S., 1951. Incipient Forest Regeneration on Great Kirk, T., 1889. The Forest Flora of New Zealand, pp. 245-247. Island, Three Kings Group. Rec. Auck. Inst. Mus. Vol. 4, pp. 99-109. Millener, L. H., 1947. A Study of Entelea arborescens R. Br. ('Whau') Trans. N.Z. Inst. Vol. 76 pp. 267-288. Buddie, G. A., 1948. The Outlying Islands of the Three Kings Group. Rec. Auck. Inst. Mus. Vol. 3, pp. 195-204. Oliver, W. R. B., 1948. The Flora of the Three Kings Islands. Rec. Auck. Inst. Mus. Vol. 3, pp. 211-238. Brothers, R. N., 1954. The Relative Pleistocene Chronology of the South Kaipara District, New Zealand. Trans. Roy. Soc. Oliver, W. R. B., 1953. Origin of the New Zealand Flora. Proc. Seventh Pacific Science Congress Vol. V. Wellington, Govern• N.Z. Vol. 83, pp. 677-694. ment Printer. Cheeseman, T. F., 1890. Further Notes on the Three Kings Islands. Trans. N.Z. Inst. Vol. 23, pp. 408-424. Percy, C. A., 1956. A Primary Survey of Marotiri Island. Tane, Vol. 7. Cheeseman, T. F., 1914. Illustrations of the New Zealand Flora. Reischek, A., 1930. Yesterdays in Maori Land, p. 97. Cheeseman, T. F., 1925. Manual of the New Zealand flora, 2nd Searle, E. J., 1956. Aspects of the Pleistocene and Recent History Ed. p. 638. of the Auckland Isthmus. New Zealand Geographer, Vol. Cochrane, G. R., 1954. A Geography of Northland's Outlying 12, No. 1. Islands. Unpublished thesis. Auckland University College. Turbott, E. G. and P. C. Bull., 1954. A Bird Census and Some Cranwell, L. M. and L. B. Moore, 1935. Botanical Notes on the Recent Observations on Birds on Great Island, Three Kings Hen and Chickens Islands. Rec. Auck. Inst. Mus. Vol. 1, Group. Rec. Auck. Inst. Mus. Vol. 4, No. 4. pp. 245-262. No. 6, pp. 301-318.

FUNGI OF MAROTIRI ISLAND

By ELEANOR CRANWELL

Fungi were collected from Marotiri during the August Corticium corniculatum G. H. Cunn. Scientific Camp, but only a limited number were found, Favolus intestinalis Berk. doubtless due to the season of the year. Most common Fomes setulosus Lloyd were the Agarics in all shades of blue, white, red and F. scuporics G. H. Cunn. fawn. Thanks are given to Miss J. Dingley of P.D.D. Fuscoporia punctata (Fr) G.H.C. Mt Albert for identification. Geastrum velutinum (Morgan) Fischer Agarics Lycoperdon scabrum (Lloyd) G. H. Cunn. Aleurodiscus ochraceoflavus (?) Lloyd L. pyriforme Schaeffer ex Pery Auricuiaria aureojuclea Scleroderma bovista Fr. Clavaria sp. Stereum lobatum Coriolus sp. (?) velutinus (Pers ex N) Tremella sp.

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