The Lichen Genus Cladonia, subsection Cladina, in
[Read before Otago Branch, August 11, 1959; received by the Editor, August 24, 1959.]
Cladonia pycnoclada, hitherto regarded as the commonest member of the subsection Cladina in New Zealand, has been recorded by Santesson as endemic to South and Central America. The present review of the New Zealand members of the subsection shows that both Cladonia pycnoclada and C. sylvatica must be eliminated from the indigenous flora of New Zealand, C. leptoclada replacing what was regarded as C. pycnoclada form flavida, C. impexa replacing C. pycnoclada f. exalbescens, and C. mitis replacing C. sylvatica C. alpestris and its f. portentosa are retained.
The subsection Cladina of the genus Cladonia has a world-wide distribution, but together with the genus Stereocaulon it constitutes the dominant vegetation of much of the Arctic tundras where three species are together known as “Reindeer Moss”. Till recently the Cladinae were deemed to be a subgenus of Cladonia, but in a recent revision of the genus, Mattick (8) placed the Cladinae as a subsection of the section Perviae in the subgenus Eucladonia. The species comprising the subsection are characterized by a crustose primary thallus giving rise to intricately branched, interlocking podetia forming compact or open cushions sometimes of considerable extent.
The surface of the podetium is rarely corticate, being more commonly arachnoidtomentose (cobwebby), with or without superficial areolae or verruculae. The colour is variously white, cream, yellow, yellowish-green, ashy, grey, or grey-green, and the ramification is variously dichotomous, trichotomous, or polytomous, or a combination of these. When one branch of a dichotomy or whorl develops more strongly than the other or others a sympodial axis may result. In some species (e.g., C. alpestris) such a sympodium may extend from base to apex, while in others (e.g., C. impexa) it may be evident only in the lower half of the podetium. Sometimes a single branch may occur between two whorls, unilaterally in C. sylvatica, divergent in C. mitis.
Apothecia and spermagonia are small or even minute, both being situated on the apices of the terminal branchlets. The spermagonial contents are embedded in either a clear or reddish jelly, the colour being constant in each species but rarely available at a suitable stage for diagnostic purposes.
Species discrimination is rarely easy. Many species are superficially much alike, and only careful examination of the ramification, the nature of the ultimate branchlets, of the colour, of the axils, and often of the lichen substances present in the podetia, can reveal the true identity of a specimen. The ultimate branchlets may be short or long, curved or straight, stout or slender, spreading or deflexed, and then unilaterally or divergent.
Santesson (11) has observed that in the Cladinae the lichen acids are fairly constant for each species, and therefore are of great value in the discrimination of single specimens; but both he and Mackenzie Lamb emphasize that in their view, “the morphology and anatomy of the plant is fundamental in species discrimination,
and the presence or absence of a lichen acid in morphologically identical specimens of a normally acid-bearing species cannot be regarded as an important taxonomic difference”. With this contention the writer is in fullest agreement Fortunately in the Cladinae morphological distinctions do separate most of the species at present recognized, and total reliance on chemical differences is rarely necessary save in the case of atypical specimens.
In his monograph of the Cladinae (2) in 1939 as modified by later amendments, Des Abbayes has grouped the various species in five categories or series termed Rangiferinae, Alpestrae, Impexae, Bicornutae, and Tenues. These groups are fairly well defined and are of much service in classification, but the observation made by Bruce Fink, in 1903, still holds good that, “Nothing but the most careful observation will enable one to determine Cladoniae with any certainty, even with the best descriptions,” and this is specially true of the Cladinae where so many species are superficially very much alike.
History of the Cladinae
For a time the only species recognized by the early lichenologists in the Cladinae was Cladonia rangiferina, though two others were listed as var. alpestris and var. sylvatica, and to these var. pycnoclada was later added. The next step was the raising of the three varieties to full specific status with the consequent limitation of C. rangiferina. From C. rangiferina, C. sylvatica, and C. pycnoclada, most subsequent species have been segregated. The relationship of the commoner species at present recognized is shown in the following table:—
In the above table species indigenous to New Zealand are indicated by an asterisk. Some forms of C. impexa, C. confusa and C. leptoclada are so closely alike in both morphological and chemical features as only to be distinguishable in the mass, and as has already been pointed out, it is sometimes necessary to know the origin of the plant before it can be named. It would be quite logical to regard these three “species” as nothing more than geographical races of C. implexa. They all contain usnic acid and perlatolic acid, and consequently are K−, P−, and KC+, where K represents an aqueous solution of KOH, P an alcoholic solution of p-phenylene-diamine, and KC an aqueous solution of KOH followed by an aqueous solution of bleaching powder.
Des Abbayes recorded that in plants formerly regarded as C. pycnoclada four species differing both morphologically and chemically could be distinguished. These
he named C. fallax (K−, P+); C. evansi (K+, P−); C. impexa (K−, P−); and C. sandstedei (K+, P+). The name C. pycnoclada was dropped by him as a “nomen confusum” on the grounds that the type had been lost and that it was uncertain which of the four species listed was in fact the typical form. Santesson, however, gave good grounds for restoring C. pycnoclada and regarding C. fallax as a synonym, as it alone of the four occurs in the Falkland Islands, the type locality. Santesson further added that C. pycnoclada was endemic to South and Central America and that plants from elsewhere did not belong to that species.
Now the history of the Cladinae in New Zealand shows that Cladonia rangiferina alone was recorded at first, to which C. pycnoclada was later added. With the segregation of C. alpestris and C. sylvatica as valid species it was seen that C. rangiferina in its restricted connotation was not present in New Zealand, though the two segregates supposedly were. However, when C. mitis was in turn segregated from C. sylvatica, it now became clear that this latter species must also be expunged from the list of indigenous species, and it may be that C. alpestroides and not C. alpestris is present.
Santesson's opinion that C. pycnoclada is restricted to South and Central America demanded a re-examination of the numerous specimens from New Zealand which Kusan, Sandstede, Allan and others had so labelled. Through the courtesy of Dr. Rolf Santesson, I received for comparison authentic material of the true C. pycnoclada from South America, whic invariably gives a P+ reaction. Though closely similar morphologically New Zealand plants in no case gave a P+ reaction. What had been regarded as C. pycnoclada var. exalbescens in New Zealand proved to be C. impexa and “var. flavida” proved to be C. leptoclada, and specimens submitted to Dr. A. W. Evans were so labelled by him. These two species contain perlatolic acid, which is absent in C. pycnoclada. Whether C. leptoclada and C. impexa should be retained as separate species I much doubt, as they intergrade to such an extent that many specimens could well be placed under either species. C. confusa, however, is a morphologically distinct plant so far as I can gather from such specimens as I have for comparison, though perhaps little more than a geographic race of C. impexa.
New Zealand plants labelled C. sylvatica all prove to be P−, whereas the true species is always P+. Though frequently lacking the characteristic unilateral deflection of the ultimate branchlets, New Zealand plants appear to be forms of C. mitis. Thus of the four species listed by our early botanists—C. rangiferina, C. alpestris, C. sylvatica and C. pycnoclada, C. alpestris alone remains as a New Zealand species. It occurs in both the typical form and as var. portentosa.
Species of Cladinae Arranged According to Des Abbaye's Classification,
With Chemical Reactions
Series 1. Rangiferinae.
Podetia with ramification mainly polytomous and with distinct sympodial axes. Tips of branchlets usually unilaterally deflexed.
|Cladonia rangiferina (L.) Web.||K+,||P+,||KC−.|
|sylvatica (L.) Hoffm.||K−,||P+,||KC+.|
|laevigata (Vain.) Gyeln.||K,||P−,||KC+.|
Series 2. Alpestrae.
Ramification mainly polytomous with distinct sympodial axes. Tips of branchlets straight and spreading round gaping axils. Spermagonial jelly red. Cladonia alpestris (L.) Rabenh. K−, P−, KC+
Series 3. Impexae.
Ramification mainly trichotomous; sympodia absent or basal only. Branches typically subequal; tips of branchlets straight and spreading or deflexed in various directions. Spermagonial jelly colourless.
|Cladonia impexa Harm.||K−,||P−,||KC+f.|
|leptoclada Des Abb.||K−,||P−,||KC+.|
Series 4. Bicornutae.
Ramification mainly dichotomous, branches typically sub-equal; sympodia absent; ultimate branches straight and spreading; spermagonial jelly colourless. P− except C. pycnoclada.
|Cladonia evansi Des Abbayes||K+f,||P−,||KC−.|
|pycnoclada (Pers.) Nyl.||K−||P+||KC+.|
Series 5. Tenues.
Ramification dense and dichotomous; sympodia absent (occasional in C. tenuis); branches slender, equal or unequal; ultimate branchlets spreading or deflexed; spermagonial jelly rose-red; P+.
|Cladonia tenuis (Flk.) Harm.||K−.||P+,||KC+.|
|sandstedei Des Abb.||K+||P+,||K−.|
|leucophaea Des Abb.||K+,||P+,||KC−.|
Notes on Cladinae Reported from New Zealand
1. Cladonia rangiferina Hoffm.
The earlier botanists interpreted many species more widely than their successors, and at the time when C. alpestris, C. sylvatica and C. pycnoclada were regarded as varieties, the record was valid. When, however, the modern restricted connotation received sanction, C. rangiferina ceased to be a valid indigen. It alone of the Rangiferinae lacked usnic acid, but it contained atronorine, which gave it a K+, P+ reaction as in the South American C. vicaria. No New Zealand Cladinae give either a K+ or P+ reaction.
2. Cladonia sylvatica (L) Hoffm.
This species has been recorded from Mt. Maungatua and Mt. Pisgah, in Otago, from Kelly Range, in Westland, and from several other localities. Most of the specimens so named in New Zealand have been examined by the writer, and in every case found to be P−, whereas C. sylvatica is always P+. Both chemically and as a rule morphologically, the New Zealand plants correspond to C. mitisy They also lack the characteristic arachnoid tomentum of C. sylvatica, which species must be expunged from the New Zealand flora.
3. Cladonia mitis Sandstede.
C. mitis f. attenuata determined for Dr. H. H. Allan by Dr. Sandstede, and C. mitis recorded by Dr. Alex. W. Evans (Rhodora 45: 434) are the only recorded occurrences of this species in New Zealand. C. mitis does not differ strongly from C. sylvatica save in its chemical reactions and in the poorer development of arachnoid tomentum, in the presence of verruculae, and in the single branches between contiguous whorls lacking the unilateral development usual in C. sylvatica. The terminal branchlets in C. sylvatica bend in one direction and become sub-parallel; in C. mitis this may occur but they are usually more divergent and sometimes either straight or only slightly curved. C. mitis is P− save occasionally at the tips.
Localities. Eglinton Valley, West Otago, det. Sandstede; Atiamuri, Rotorua (leg. K. W. Allison, det Evans); Maungatua (leg. J. S. Thomson, Herb. D. S. I. R. as A.4 and A.10); Longwood Range (leg. J. S. Thomson, Herb. D. S. I. R. as A.11 and T.2971; det. W. M.): Mt. Pisgah, in moss (Herb. D. S. I. R., leg. J. S. Thomson.
as A.47, T.1912, and S.150: det. W. M.): Kelly Range D. S. I. R. No. 2396; det. W. M.).
4. Cladonia pycnoclada (Pers.) Nyl.
Hitherto this has been regarded as the commonest member of the New Zealand Cladinae. As mentioned above, Santesson has stated that the New Zealand plants so named by Vainio were not that species. Through the courtesy of the director of the D. S. I. R. I. have examined the extensive collections housed in their herbarium and find that not one is P+, as all plants of the South American species are, and all lack perlatolic acid. Morphologically the two species are much alike, but it is clear that if important chemical distinctions are to be maintained as specific characters then “f. flavida”, as many are labelled, must be replaced by C. leptoclada, and “f. exalbescens” by C. impexa. However, these two “forms” merge in so many cases so that it is difficult to relegate many specimens to the correct group. The difference in colour is the best guide, but intermediate shades exist so that no clearly defined colour boundary separates C. leptoclada from C. impexa. Indeed, C. leptoclada and C. impexa, but for the presence of both in New Zealand, might have been regarded as mere geographic races of a single species—namely, C. impexa.
5. Cladonia leptoclada Des Abbayes.
This species was segregated from C. impexa by Des Abbayes to incorporate plants from Central Africa, New Caledonia and New Zealand which in the mass had a different aspect and a yellower colour. The South American equivalent was similarly segregated as C. confusa by Santesson. The differences between these three species (?) are so slight that it would often be necessary to know the source from which a specimen had been obtained before it could be named (4). All three contain usnic and perlatolic acids; all three show dichotomies and trichotomies round open or closed axils; all tend to produce sympodia in their lower parts; while their surfaces and ultimate branchlets are very similar. Apart from slight differences in density of branching and in the colour, there is little to differentiate this species from C. impexa C. pycnoclada lacks perlatolic acid and is P+, and though C. leptoclada may sometimes be lacking in perlatolic acid, it is invariably P− What has formerly been regarded in New Zealand as C. pycnoclada var. flavida must now be labelled C. leptoclada, though with the reservation that this species may ultimately be merged into C. impexa, from which it had been segregated, as a colour form.
Localities previously recorded include Kaiteriteri, in Nelson; Cleddau Valley, in West Otago; Awarua, in Southland; Lake Manapouri; and Stewart Island. The following specimens in Herb. D. S. I. R. are transferred from C. pycnoclada to C. leptoclada Mt: Egmont (A. 2); Herekino (A. 3); Whangarei (A. 12 and A. 20); Little Barrier Is. (A. 9), Hen and Chicken Islands (A. 15), Poor Knights Islands (A. 26); Mt. Moehau (A. 24, A. 27)., Rangitoto Is. (A. 28, A 30, A 45); Kaihere (A. 42), Kaingawa (A. 7); Matauhi Bay (A. 8), Ruakura (A. 21), Rotorua (A. 14); Hutt Valley (A. 18); Bull Mound (A. 19); Chelsea (A. 22); Kirita Bay (A. 31); Mt. Maungatua (A. 6, A. 41); Lee Stream (A. 32); Verterburn (A. 34); Greymouth(A. 33, A. 36, A. 37).
6. Cladonia impexa Harm.
This species was deemed almost cosmopolitan by Des Abbayes, who included both New Zealand and Hawaii in its range as well as South America. Magnusson soon showed that Hawaiian plants were distinct and named them C. Skottsbergii. Similarly, Santesson segregated South American plants as C. confusa, and Des Abbayes himself segregated C. leptoclada, leaving C. impexa in its restricted connotation as a plant possibly confined to the Northern Hemisphere. Evans (4) who
accepted this distribution, later confirmed my own view that specimens sent him by me were in fact C. impexa. Thus both C. impexa and C. leptoclada are indigenous to New Zealand. Typical plants of the former are dull grey-green, while typically C. leptoclada is yellowish or yellowish-green. In both, thyrsoid heads are common, as in C. alpestris, the surface is dull and more or less areolate, and branching is commonly in whorls of three or more, rarely four or even five round open axils. The ultimate branchlets are commonly straight or slightly curved and spreading, two and three being the usual number. Plants formerly labelled C. pycnoclada f. exalbescens in New Zealand must now be transferred to C. impexa; but it must be remembered that there is no clear line of separation between these two species in New Zealand.
Localities. New Zealand (Des Abbayes); Eastbourne, Wellington (leg. W. M., det. Dr. A. W. Evans); Haywards, Wellington (leg. H. H. Allan, det. W. M); Awarua (W. M.).
7. Cladonia alpestris (L.) Rabenh.
Cladonia alpestris has a very characteristic structure and appearance. The axis is sympodial, with frequent whorls of from three to six branches round gaping axils. An occasional dichotomy may also be evident. The apical whorl usually consists of short, straight branchlets forming a starlike fringe round a gaping central hole. These are never tipped with brown as is common in some other species. The colonies are normally white or faintly yellow, though the basal parts may be somewhat dingy. The upper branches commonly form round, thyrsoid heads. C. alpestris and plants formerly listed as C. pycnoclada have sometimes been confused, and one foreign authority has suggested that all southern records may have been based on the latter species This, however, is not so, for both the normal form and f. portentosa undoubtedly occur.
As in other lands, this species in New Zealand shows a liking for sandy soils, especially in coastal areas, as at Awarua and at Sandy Point, near Invercargill. It also occurs on pumiceous soils in the Taupo and Rotorua areas and on peat at Awarua. If the absence of red conidiangial jelly be deemed a specific difference, this species may be C. alpestroides Des. Abb.
Localities. Mt. Maungatua, Otago (J. S. T., 2927); Awarua, Southland (W. M., —); Sandy Point Reserve (G. C. Martin and W. M., 5605); Taupo (K. W. Allison); New Zealand (Sinclair, Haast); Key Summit (J. S. T., 2927).
Var. portentosa—New Zealand: C. Knight, Müll Argov; Maungatua (J. S. T., 2146); Sandy Point (W. M., 5606 and G. C. Martin).
Of the seven species attributed at various times to New Zealand, only four may now be deemed indigenous. The evidence indicates that neither C. pycnoclada nor C. sylvatica is present, the plants formerly so regarded being C. impexa and C. leptoclada, and C. mitis respectively. Both these species are strongly P+, whereas all New Zealand Cladinae are P—. It was formerly held that C. impexa, C. leptoclada and C. confusa were confined to distinct geographic regions, but the former two both occur in New Zealand. While I retain C. leptoclada as a distinct species. it is probably more correct to regard it as merely a form of C. impexa.
My study of the New Zealand Cladinae has been greatly aided by assistance from many quarters My thanks are due to the late Dr. A. W. Evans for literature, specimens and determination of species. Dr. R. Santesson, Dr. S. Hattori, Dr. O.
Clement, and Dr. W. Culberson have assisted by furnishing comparative material. Mr. A. J. Healy, Asst. Director of the Botany Division of the D. S. I. R., has made available all specimens housed in the D. S. I. R. herbarium and literature housed in the library. Dr. James Murray has facilitated access to the Thomson collection, housed at Otago University. Mr. G. G. Hamlin, Botanist to the Dominion Museum, at Wellington, facilitated my examination of collections housed in the herbarium of that institution, and Dr. W. P. Philipson has forwarded collections made near Cass, in western Canterbury. I am also indebted to Mr. P. Havard Williams, Chief Librarian at the Otago University, for securing literature not locally available.
1. Allan, H. H., 1937, The Cladoniae of New Zealand Report A. N. Z. A. A. S., Vol. 23, 337–8.
2. Des Abbayes, H., 1939, Revision Monographique des Cladonia du sous-genre Cladina. Bull. Soc. Sci. Bretagne 16: 2. 1–156.
3. Duvigneaud, P. and Bleret. L., 1940. Notes de microchemei lichénique 11. Sur la valeui systematique de Cladonia pycnoclada (pers) Nyl. emend. Des Abbayes. Bull. Soc. Roy Bot. Belgique 72. 155–159.
4. Evans, Alexander W., 1955. Notes on North American Cladoniae. Bryologist 58: 2 93–112.
5. Hooker, J. D., 1855. Flora Novae-Zelandiae, Vol 2. London.
6. — 1867. Handbook of the New Zealand Flora, Part 2. London.
7. Martin, W., 1958. The Cladoniae of New Zealand. Trans. Roy Soc. N. Z. 85: 603–632.
8. Mattick, F., 1938. Systembildung and Phylogenie der Gattung Cladonia Bot. Centrbl. Beikefte 58b: 215–234.
9. — 1940. Uebersicht der Flectengattung Cladonia in neuer systematischer Anordnung. Feddés Repert Spec. Nov Regn. Veg. 49: 140–169.
10. Muller, J. (Argov.) 1892. Lichenes Knightiana, in Nova Zelandia lecti. Soc. Roy de Bot. de Belgique 31: 22–42.
11. Santesson, R., 1942. The South American Cladinae. Arkiv for Bot 30A, No. 10, 1–27.
12. Zahlbruckner, A., 1941. Lichenes Novae-Zelandiae a cl. H. H. Allan eiusque collaboratibus lecti. Denkschr. Akad. Wiss Wien, math-naturwiss Kl 104:258.
Mr. William Martin,
27 Merchiston Street,
Dunedia, E. 1, N. Z.