Boletus leptospermi displays a marked ecological preference for Leptospermum scrub or forest containing L. ericoides. Field observations suggest that it may form mycorrhizas with members of this genus.

Boletus leptospermi falls within sect. Subpruinosi as defined by Singer (1947). Of the species included in this section, it appears to be most closely related to a group of East Asian species, which includes B. nanus Mass. and B. aureomycelinus Pat. and Baker, by reason of the short spores (Q=2 or less) and disorganised trichodermium. However, in contrast to the latter species, the basal mycelium of B. leptospermi is white instead of yellow. The hymenophoral trama of B. leptospermi is not entirely typical of the Boletus subtype for, although the mediostratum is heavily pigmented, the hyaline lateral stratum is mixed rather than strongly divergent.

B. leptospermi is characterised by the multicoloured pileus, brightly coloured, subglabrous to finely subvelutinate stipe, broad spores, and bluing hymenophore and context.

COLLECTION EXAMINED: Under L. ericoides and L. scoparium, Auckland, Kerikeri, Opito Bay, 26 Apr 1966, G. B. Rawlings (HOLOTYPE, PDD 25896).

The xerocomoid habit, subvelutinate stipe, medium to large pores, and cuticle composed of a poorly organised trichodermium indicate that Boletus rawlingsii belongs in sect. Subpruinosi as defined by Singer (1947).

The species is named in honour of Mr. G. B. Rawlings, who first collected this fungus and whose fieldwork on the introduced Boletaceae of this country amply deserves recognition.

B. rawlingsii may be recognised by the yellow fruitbodies, unchanging context and hymenophore, and broadly elliptic-subfusiform spores.

Gyroporus castaneus is widely distributed throughout temperate regions of the northern hemisphere, where it occurs in association with both coniferous and broad leaved trees. The fact that both the above collections were found in relatively undisturbed native forest suggests that it is indigenous to New Zealand. Singer (1945b) noted an unconfirmed report of its occurrence in Australia, but did not state whether it was indigenous or introduced. G. castaneus is reported to be an edible fungus by European mycologists.

The species is readily recognisable by the chestnut brown fruit bodies, hollow stipe, pallid stramineous spores, and presence of clamp connections. It has not previously been recorded from New Zealand.

TYPE LOCALITY: France.

It seems likely that Phaeogyroporus portentosus is an indigenous species, for an immature specimen, indistinguishable from similarly aged specimens of  P. portentosus, has been collected in dense native forest near Rotorua by Mr. G. B. Rawlings. When the natural geographical distribution of the species is considered (Australia, Ceylon, Indonesia), its presence in the warmer parts of New Zealand is not unexpected.

The mycorrhizal status of P. portentosus is uncertain. Earlier descriptions contain little information about its habitat, but, on the basis of field observations, Fisch (1945) suggested that in Australia it formed mycorrhizal associations with Eucalyptus. The fungus has appeared in the Auckland Domain for a number of years and is restricted to a small area in a planted border of native trees and shrubs. The only plant with which it could form an association in this area is a single tree of Nothofagus truncata. The collection from Meadowbank was not associated with any known mycorrhizal plant.

New Zealand specimens agree closely with earlier descriptions of the species and with Australian specimens identified by Cleland (ADW), except that both Fetch (1907) and Boedijn (1951) described the pileus as smooth. P. portentosus readily fits within Singer's (1962) circumscription of Phaeogyroporus. although cystidia are absent. It seems likely that Phaeogyroporus is a later synonym of Phlebopus (Heim) Singer 1936. Singer (1962) regarded Phlebopus as a nomen dubium on the doubtful grounds that the type specimen of Boletus colossus Heim, the only species originally described in the genus, was no longer in existence. Heim (1965) recently pointed out that specimens of B. colossus are preserved in Paris (PC). The two genera appear to be closely related and, if on re-examination of B. colossus the presence of clamp connections is demonstrated, it will be difficult to maintain them as separate genera.

The genus Phaeogyroporus contains some of the largest Agaricales known: Cleland (1935) reported that specimens of P. portentosus reached 60 cm in diameter and weighed up to 7 lb 2 oz. P. portentosus is regarded as an edible species in Australia.

The species may be distinguished by the large, olive brown fruitbodies, short-elliptical spores, and the presence of clamp connections. It has not previously been recorded from New Zealand.

Suillus brevipes is an introduced species typically associated with 2-and 3-needle pines in North America. Three varieties of S. brevipes have been described, all based primarily on colour differences and minor morphological characters such as length of stipe. New Zealand collections agree most closely with the type variety.

In some fruitbodies the stipe is somewhat longer than is usual in var. brevipes. This difference is perhaps not important for, as Smith and Thiers (1964) pointed out, the length of the stipe probably '"depends largely on the compactness of the substratum. A possibly more significant character is the reddish coloration at the extreme base of the stipe. This character, which is relatively constant in New Zealand collections, was noted by Coker and Beers (1943), but was not mentioned by Singer (1945b) and Smith and Thiers (1964).

S. brevipes has been found only in association with Pinus radiata in New Zealand. An interesting situation was observed at Woodhill State Forest in autumn 1966 where Suillus brevipes was fruiting abundantly under Pinus radiata, but was absent from adjacent compartments of P. pinaster and other species. The fruiting period of Suillus brevipes often extends well into the winter and in 1966 and 1967 it was still fruiting when all other Suilli had disappeared. Coker and Beers (1943) and Smith and Thiers (1964) also noted that it often appeared late in the season. It is reported to be an edible species by North American writers.

S. brevipes is allied to S. granulatus, but may be distinguished by the relatively short stipe, paucity or absence of glandulae and typically darker colour of the pileus. The range in colour of the pileus is similar to that encountered in S. luteus. S. brevipes has not previously been recorded from New Zealand.

TYPE LOCALITY: New York State, U.S.A.

Suillus granulatus is an introduced species associated with Pinus in the temperate zone of the northern hemisphere and is widely distributed in both Europe and North America. The relatively large degree of variability encountered in Suillus granulatus over its natural geographical range has resulted in the recognition of a large number of infraspecific taxa. Of the more recent attempts to divide the species the most comprehensive treatments are those of Singer (1945a) and Blum (1965).

Singer distinguished four subspecies on the basis of minor differences in spore size, small differences in colour of the fruitbodies, geographical distribution, and mycorrhizal associations in nature. The results of applying this classification to New Zealand specimens are inconclusive, for many collections possess spore and colour characters intermediate between two subspecies. However, it should be noted that Singer's classification arose from observations on specimens growing in their indigenous habitats. It is possible that under New Zealand conditions, where both fungus and mycorrhizal partner have been introduced, a degree of morphological modification of Suillus granulatus has occurred, with the result that subspecific differences are no longer distinct. The high degree of taxonomic significance attached to mycorrhizal associations of the subspecies by Singer (1945a) is not supported by field observations in New Zealand. No constant differences could be found between specimens growing under Pinus strobus and P. pinaster, although according to Singer these specimens should belong to Suillus granulatus ssp. snellii Singer and ssp. leptopus (Pers.) Singer respectively.

Blum (1965) recognised five varieties of S. granulatus based primarily on spore size and colour differences in the fruitbodies. As with Singer's scheme, it is not possible to place New Zealand specimens with any degree of certainty using this classification.

In view of the difficulties in assigning them to any of the described subspecific taxa, New Zealand collections are simply referred to the species. Smith and Thiers (1964) also encountered difficulty in defining S. granulatus ssp. snellii, the subspecies restricted to North America, and relegated it to the excluded species. Smith and Thiers (1966) later concluded that a number of variants of S. granulatus existed, in which small variations in spore size were apparently correlated with certain groups of the genus Pinus. Four variants were distinguished on this basis but because of the small differences involved, it was considered not worth naming them.

Suillus granulatus is an excellent edible fungus but as with most Suilli, the mucilaginous pellicle of the pileus should first be removed,

S. granulatus may be recognised by the buff yellow, tan, or reddish tan pileus, presence of glandulae on the stipe, and absence of an annulus. Which was first recorded from New Zealand by Walker (1931).

Suillus grevillei is an introduced species, which under natural conditions forms mycorrhizal associations solely with Larix. However, Young (1940) has shown that in pure culture it is capable of forming mycorrhizas with Pinus caribea and P. taeda. In New Zealand it is commonly associated with Larix decidua and has been observed under L. leptolepis (W. A. Holloway, pers. comm.).

Slipp and Snell (1944) and Smith, Thiers, and Miller (1965) recorded exannulate fruitbodies of Suillus grevillei. In one of the above collections (24341), a quarter of the fruitbodies lacked an annulus, and in some there were no indications of velar remnants on the pileus margin. The species is reported to be edible, but opinions differ as to its quality.

S. grevillei may be distinguished by the presence of an annulus, absence of glandulae on the stipe, and its association with Larix. Which was first recorded from New Zealand (as Boletus elegans) by Rawlings (1951).

TYPE LOCALITY: Scotland.

COLLECTIONS EXAMINED: Under Pseudotsuga menziesii, Auckland, Rotorua, Hikurangi State Forest, May 1964, J. W. Gilmour and R.F.R. McN., 23606; J. M. Dingley and G. B. Rawlings, 23607; Canterbury, Ashley Forest, Jul 1964, R. M. J. Mackenzie, 23601; Winchester, Mar 1966, R.F.R. McN., 25089; Marlborough, Rai-Wangamoa State Forest, Apr 1965, W. A. Holloway, 24639; Nelson, Golden Downs State Forest, Apr 1965, W.A.H., 24640.

S. luteus is common in the exotic coniferous plantations of New Zealand and may be recognised by the presence of glandulae and a broadly sheathing annulus on the stipe. In mature fruitbodies growing under wet conditions the annulus may disintegrate leaving little trace. The first record of the species in this country appears to be that of Walker (1931).

Suillus lakei is endemic to the west coast of North America where it is typically associated with Pseudotsuga. In New Zealand it occurs only under P. menziesii. Smith and Thiers (1964) erected a variety of Suillus lakei, var. pseudopictus, which differed from the type in the redder and more scaly pileus. On these characters, New Zealand collections agree most closely with var. pseudopictus. In the type description of S. lakei, however, Murrill described the pileus as " . . . fulvous with latericeous tints, appearing testaceous, densely imbricate-floccose-scaly . . . ". It appears that the differences between the two varieties are not constant and, for this reason, the above collections are described under the type variety.

There is some disagreement as to the specific status of this fungus. Singer (1966) recently considered S. lakei a synonym of Boletinus amabilis (Peck) Snell, and transferred the latter species to Suillus. Before this, Singer (1945b) had tentatively separated the two by differences in spore width, but in the later publication considered that the range in spore width overlapped to a large extent and that the differences were largely imaginary. In contrast. Smith and Thiers (1967) maintained S. lakei and S. amabilis as distinct species on the grounds of differences in spore size and shape, context colour, cuticular structure, and habitat. In all New Zealand collections the spores are less than 4 µm. wide and thus agree with measurements from the type of S. lakei as described by Smith and Thiers (1964) rather than those obtained by either Singer (1966) or Smith and Thiers (1967) from the type of S. amabilis. At present it is considered preferable to regard S. lakei as a distinct species.

S. lakei may be distinguished by the squarrose, often red-tinted pileus, radially elongated pores, and annulate stipe. Was first recorded from New Zealand by Rawlings (1958).

TYPE LOCALITY: Corvallis, Oregon, U.S.A.

Suillus luteus is an introduced species indigenous to the temperate zone of the northern hemisphere.

Singer (1945b) considered that in its natural habitat, S. luteus was associated with 2-needle pines belonging to sect. Lariciones of the genus Pinus, but later (Singer, 1965) added Picea abies and possibly Larix decidua to the list of mycorrhizal partners. Smith and Thiers (1964) commented that Suillus luteus occurred with Pinus and Picea in North America and remarked that its distribution in native coniferous forests was yet to be ascertained. It seems likely that over its natural geographical range Suillus luteus shows a preference for certain species of 2-needle pines, but in New Zealand is capable of forming associations in the field with species of 2-, 3-, and 5-needle pines in the absence of its preferred partners. Experimental data support this conclusion, for in pure culture S. luteus has been shown to form mycorrhizas with a number of 2-, 3-, and 5-needle pines as well as Picea abies, Larix decidua, and L. occidentalis (Slipp and Snell, 1944). Birch (1937) has proved experimentally that Suillus luteus forms mycorrhizas with Pinus radiata in New Zealand.

Suillus luteus is an excellent edible fungus. Only young and firm fruit-bodies should be selected, and the mucilaginous pellicle of the pileus should first be removed.

TYPE LOCALITY: Europe.

Suillus piperatus is an introduced species indigenous to temperate regions of the northern hemisphere. Of the two commonly recognised varieties of this species, var. piperatus and var. amarellus (Quel.) Singer, New Zealand collections agree with the type variety. The possession of a reddish hymenophore is an unusual character among the Suilli. This character, together with the absence of both glandulae and an annulus, led Singer (1938) to erect the section Piperati to accommodate Suillus piperatus. Two further species were later transferred to this section by Singer. Smith and Thiers (1964) excluded sect. Piperati from Suillus on the grounds of a number of features correlated with the reddish hymenophore, but did not suggest an alternative disposition of the section.

Suillus piperatus also differs physiologically from other Suillus. Tyler, Benedict, and Stuntz (1965) showed that of the 17 species of Boletaceae tested for urea accumulation, including nine species of Suillus, only S. piperatus showed a moderate level of urea; the remainder were urea-negative. It would be of interest to see whether tests on S. rubinus (W. G. Smith) O. Kuntze and S. rubinellus (Peck) Singer, the remaining two species included in sect. Piperati by Singer (1962), produced similar results.

It has been shown in Europe and North America that S. piperatus is capable of forming mycorrhizal associations in nature with many genera of conifers as well as angiosperm genera such as Fagus, Quercus, Betula, and Populus. In New Zealand, the species has been collected only under introduced conifers. Rawlings (1951) recorded its association with Pinus contorta var. latifolia and P. ponderosa, in addition to the two species named above.

The peppery taste of Suillus piperatus makes it unsuitable for eating in quantity. However, it is not a poisonous species and may be added in small quantities to other edible species to sharpen the flavour.

S. piperatus is characterised by the dry to slightly mucilaginous pileus, reddish hymenophore, absence of glandulae and an annulus, and small fruitbodies. Was first recorded from New Zealand by Rawlings (1951).

SPORES: spore print yellowish brown (between Cinnamon and Clay Color); spores pallid melleous, elliptic-subfusiform to oblong-elliptical, 7.8-9.1-(9.8) X 3.0-3.6-(3.9) µm, smooth. HYMENIUM: basidia hyaline, clavate, 21-30 X 5-7.5 µm., 4-spored; cystidia crowded in groups at or near tube mouths, no solitary cystidia seen, thin-walled, subclavate to clavate, 35-70 X 5.5-8.5 µm., vinaceous in KOH. HYMENOPHORAL TRAMA: bilateral of the Boletus subtype; clamp connections absent. CONTEXT OF PILEUS: white to pallid yellow, usually with large brownish areas, unchanging on exposure to air. TASTE: mild. SMELL: not distinctive. CHEMICAL REACTIONS: KOH on pileus—dark brown with vinaceous tints; on context of pileus—immediate, red flush turning mauve; NH4OH on pileus—dark reddish brown; on 'context— faint red to mauve.

Suillus subacerbus is probably of North American origin. In New Zealand it has been found only in association with Pinus radiata.

Suillus subacerbus appears to belong to the S. granulatus - S. pungens -S. acerbus complex of species as described by Smith and Thiers (1964) in their extensive study of North American Suilli. Of these species, S. subacerbus is most closely related to S. pungens Thiers & A. H. Smith and S. acerbus A. H. Smith & Thiers, both of which are recently described species naturally associated with Pinus radiata in California. However, it differs from both these species in a number of characters. In pileus colour, Suillus subacerbus most closely resembles S. pungens, but differs in the absence of a marginal roll of white tissue when young, shorter spores, vinaceous colour produced by KOH on cuticle and cystidia, and absence of a harsh taste and strong pungent smell. It is perhaps more closely related to S. acerbus, from which it may be separated by the combination of colours in the pileus, smaller spores, constant vinaceous colour produced by KOH on cuticle and cystidia, and absence of an unpleasant taste. Although these may appear to be but minor differences, the distinctions between many species of Suillus are not great, and S. subacerbus cannot satisfactorily be accommodated within any of the species so far described.

S. subacerbus may be distinguished from other Suilli occurring in New Zealand by the combination of colours in the pileus, presence of glandulae, absence of an annulus, and vinaceous colour reaction to KOH.

The above description differs from that of Stevenson in that cystidia are numerous and distinct, the range in spore size is considerably greater, and the spore print is brownish orange. The unchanging, bitter tasting context which does not stain yellow with KOH indicates that Tylopilus formosus belongs in sect. Tylopilus as defined by Singer (1962).

Field observations strongly suggest that T. formosus is capable of forming mycorrhizal associations with both Nothofagus and Leptospermum.

Tylopilus formosus may be recognised by the velutinate, dark brownish-black pileus and stipe, pallid brownish-orange hymenophore, and white, bitter tasting context.

Xerocomus chrysenteron is an introduced species, which is widely distributed throughout temperate regions of the northern hemisphere. In its native environment it occurs under both coniferous and broadleaved trees. There are conflicting reports in the literature as to the edibility of this species and it appears that it is not highly esteemed as an edible fungus.

X. chrysenteron may be distinguished by the dry, irregularly creviced pileus which shows a red or pink colour in the crevices, red streaked stipe, and hymenophore which rapidly turns blue where damaged. It has not previously been recorded from New Zealand.

TYPE LOCALITY: France.

The short, smooth-walled spores and hymenophoral trama of the Phylloporus subtype indicate that this species belongs in the Boletaceae rather than Strobilomycetaceae. It readily fits within Xerocomus, but in the absence of information on the ammonia reaction of fresh pilei it is not possible to assign it to one of the sections recognised by Singer (1962).

X. lentistipitatus may be recognised by the dry, pallid brown to cinnamon brown pileus, yellow hymenophore, and pallid stipe. The presence of basal rhizomorphs appears to be a relatively constant character.

Xerocomus mcrobbii has the general appearance of a Boletellus, but may be distinguished from members of that genus by the short smooth spores and hymenophoral trama of the Phylloporus subtype. Although the ammonia reaction of fresh pilei is not known, the short spores (Q=2) indicate that Xerocomus mcrobbii most probably belongs in sect. Pseudogyrodontes. The fact that it has been found only under Nothofagus in two widely separated localities suggests that it is a mycorrhizal species.

Xerocomus mcrobbii may be recognised by the olive pileus, which becomes fibrillose-scaly at maturity, yellow tubes and deep red pores, and short spores.

The elongate spores and absence of ammonia reaction of fresh pilei indicate that Xerocomus nothofagi belongs in sect. Xerocomus. The collection of the species under Nothofagus in three widely separated localities suggests that Xerocomus nothofagi may form mycorrhizal associations with members of this genus.

X. nothofagi may be distinguished from other Xerocomus species occurring in New Zealand by the relatively large fruitbodies, dull carmine pores, and apically concentrated pink to carmine granulae on the stipe.

Xerocomus rufostipitatus cannot be placed in one of the sections recognised by Singer (1962) as the ammonia reaction of fresh pilei is not known.

The species may be recognised by the velutinate, cocoa brown to chocolate brown pileus, dark red pores and stipe, and small fruitbodies. X. mcrobbii also possesses dark red pores and a reddish stipe, but differs in the coarsely fibrillose-scaly pileus, yellow base to the stipe, and broader spores.

In the absence of information on the ammonia reaction of fresh pilei it is not possible to insert Xerocomus squamulosus into Singer's (1962) subgeneric classification.

The species is characterised by the cinnamon brown to chestnut brown, finely squamulose pileus, yellow hymenophore, which turns greenish blue where damaged, and large angular pores.