ASBS Newsletter – Book Review

Grevillea (Proteaceae).
A Taxonomic revision.

written by D.J. McGillivray, assisted by R.O. Makinson.

(From ASBS Newsletter Number 74, March 1993)

Published by: Melbourne University Press. 1993.
480 pp. ISBN 0-522-84439-1. $215.

The name Grevillea commemorates Robert Greville, "a gentleman eminently distinguished for his acquirements in natural history, and to whom the botanists of this country are indebted for the introduction and successful cultivation of many rare and interesting native plants". So wrote Robert Brown when he took up Dryander's name for the genus in 1809. Nowadays, if you wish to find out more about Greville, he is better known for his role as "protector" of the lady whom he later prevailed upon to marry his uncle and become the notorious Lady Hamilton. That same uncle was reputed to have been responsible for introducing into England the process of lithography. No doubt both would be amazed at the sight of the new Grevillea book.

The size is large coffee-table format, with an eye-catching colour reproduction of the flowers of G. tripartita on the front cover. Coverage in a two-column format is of 253 species, each with a comprehensive c. 500-word description, a separate and detailed account of the distribution of colour in the flower, flowering time, ecology, uses, reference to other illustrations, discussion of variation, and a distribution map. Identification of the species is via a key to 11 artificial groups, but the species themselves are arranged in "natural" groups concerning which there are further notes included in an appendix. The synonymy and typifications of all species is removed to a separate nomenclatural section at the back.

Illustrations of species are by excellent colour photographs, coupled with line drawings to help in interpretation. Layout has ensured that there is a map, line drawing or colour photograph on every double page, greatly adding to the overall appeal of the book. There are 65 species that are not illustrated by a line drawing or photograph; 30 of these have references to illustrations elsewhere. The other 35 species are usually only represented by a small number of collections, e.g. G. granulosa McGillivray, G. rosieri McGillivray, G. pinifolia Meisn, and G. disjuncta F. Muell.

Very seldom these days would a revision of such a large Australian genus appear without a considerable number of new species. This one officially has only one (G. subterlineata R. Makinson), since all of McGillivray's new names were published in 1986. It is, however, the first time that these new species (53 in all) and subspecies (34) have been described in detail. A half-sized reproduction of "New Names in Grevillea", the 1986 publication in which they were formalized, is included as an appendix.

The introductory chapters are brief, consisting of a short introduction, a chapter on morphology, the method for preparing descriptions, and a glossary to special terms. The seven pages on morphology have a great deal of detail for each organ of the genus, and are followed by two detailed pages on how measurements of some of these organs such as the perianth, pistil, nectary, fruit and seeds have been made.

The part of this revision that will no doubt receive the most use is the key to species, in conjunction with the glossary and the chapter on morphology. Any material that is purely vegetative or only with fruits will be impossible to identify, since the key to groups requires a knowledge of floral characters. My testing of the key was performed in two ways, the first by using the descriptions as they appear in the revision, and the second by taking a box of backlog material from AD.

From the descriptions: On the whole, by taking a species and keying it out from the written description most species of those tested appeared in all of the groups that they should have done. However, G. thelemanniana should also be included in those species in the key to Group 3, and G. argyrophylla should be included in the key to Group 10.

From specimens: In keying out a box of backlog specimens of Grevillea, it was found that once one became familiar with the terminology, with the help of the glossary and the detailed morphology chapter, there were usually few problems. The inflorescence shape, often difficult to discern from dried material, probably caused the most headaches; an understanding of the temi "secund" is assumed as it has not been defined in the glossary or in the descriptive characters. Either my determination was wrong or the accuracy of the distribution map for G. juncifolia is suspect, as a specimen that keyed out this species came from 70 miles S of Darwin, which is outside the area shown for the distribution of that species.

It should be noted that within the group keys reference is to the species number rather than the page number. As each page has the species name and species number at the top, this aids in finding the relevant species quickly.

Probably the most controversial aspect of this work is the decision not to recognize much of the infraspecific variation formally. Where there is variation, and this applies to a great many of the species, there is an extremely detailed discussion. It would appear to this reviewer, particularly where taxa have been described, mapped or keyed out (e.g. under G. hookeriana, G. tetragonoloba, G. fasciculata, G. brachystylis, G. pityophylla, etc., etc.), that in the interests of stability of the broad species concept adopted, it might have been preferable to formalize them. The use of multiple terms (forms, races, elements, and entities) to represent these informal taxa is confusing, as is the statement on p. 399 that "informal ranks 'race' and 'form' have been used when lack of definition or paucities of difference or data have made recognition of subspecies inappropriate. In general current Australian practice, 'race' as used here is equivalent to subspecies."

The lack of any formal recognition of many infraspecific taxa has already had ramifications. G. calliantha, here treated as an entity of G. hookeriana, but described by Makinson & Olde as a separate species in 1991, is included on the list of taxa added to the Proposed National List of Endangered Plants (Australian Network for Plant Conservation 1993). What will happen to it now? If it reverts back to G. hookeriana then it is presumably no longer endangered! Wrigley (1989), in his account of Grevillea in Banksias, Waratahs and Grevilleas, although having access to McGillivray's new names, chose to retain a number of species sunk here by McGillivray (e.g. G. ninghanensis, G. rogersii), since he considered that they "deserved separate recognition, at least horticulturally." Similarly, it is W.R. Barker's intention to continue (Barker 1989) to leave G. rogersii (equivalent to the "small-leaved form" of G. lavandulacea, and confined to the western end of Kangaroo Island) in the South Australian Census as it is counterproductive to merely sink it into the great morass of variation of the parent species.

Although I would agree with the outcomes from the nomenclature chapter, there is room for controversy. Some of the decisions made would surely have occupied the "consistent pedant" for several agonised pages of Kew's unofficial Nomenclatural Forum, and were perhaps deserving of some discussion in the introduction. These include the decision to use the term lectoparatype (or ?paralectotype), and to refer to the duplicate sheets of the lectotypes, which may or may not have been seen by the author and thus form part of the protologue, as "parts of the type collection". What, one wonders, is the annotation on the type sheet? Similarly, on p. 430 there is a rejection of the earlier name Lysanthe podalyriifolia Knight for G. mucronulata R.Br. on the basis of not being able to produce a neotype, and also so as not to "promote the principle of priority beyond its proper bounds". But what are those bounds?

I would take issue with the statement that invalid names are not mentioned as they are best forgotten. Invalid names include manuscript names, and in a work such as this, which is after all a revision of the genus, a true history of the species involved should be presented. To do this entails a consideration of all names, whether they be validly published or not. For instance, Solander, Dryander, Robert Brown, and Salisbury/Knight all worked on the same specimens, and it is often only through consideration of their manuscript names that it is possible to establish the sequence of events that led to publication and to identify those specimens that should be considered in lectotypification. Nor is it, true to say that manuscript names have not been mentioned here, since they are sometimes quoted within the lectotypifications, e.g. under G. baueri and G. buxifolia ssp. buxifolia.

It has to be said that I did find it difficult to get an overview of the genus from the book. The appendix indicating relationships within the genus needs to be cross-referenced to the "natural" groups recognised in the text (e.g. species 1-47, G. pteridifolia and related species correspond to Group 1 of the appendix, species 48-52 correspond to Group 6, and it also needs considerably more information as to character states. This would perhaps have been best supplied by producing a key to the natural groups, as in the traditional conspectus.

From my point of view as part of the team responsible for revising the sister genus Hakea, reviewing this book has been a fascinating exercise. The terminology used differs slightly from that used for Hakea, a problem that will need to be overcome for the forthcoming treatment of the two genera in the Flora of Australia, and also for any cladistic analysis of the two genera.

In contrast to Hakea, where the diversity tends to be in both the flowers and the fruit, in Grevillea, where the fruit is usually not retained, the greatest diversification appears to be within the flowers. Colour and its distribution within the flower tends to be more variable than in Hakea, easily justifying the treatment of the flower colour as a separate heading at the end of each description. Black features in a number of species restricted in their distribution, e.g. G. benthamiana has a black perianth and G scortechinii and G. hookeriana have black styles, and it would be interesting to know whether this has any significance in the pollination of these species.

Other parallels seen within the two genera can be found in perianth shape. Within Hakea there is a group in which the tepals remain coherent except along the dorsal surface. All have large red flowers and are bird pollinated. However this same coherence of the tepals within Grevillea seems to have arisen for a different purpose, as here the flowers are relatively small and not red. Both genera have a group of species with straight buds, Section Manglesia of Grevillea (12 spp.) and Section Manglesioides of Hakea (4 spp.); all species with the exception of G. anethifolia, arc confined to southern Western Australia. Pendent inflorescences are found within G. thelemanniana and also in Hakea pendans.

Within the fruit, similar excrescences and shapes are found in Hakea rhombales and G. pectinata, but no mature fruits of Hakea are known to produce sticky exudatcs as in G. petropholoides and other Grevillea species. G. annulifera and G. glauca exhibit the same round fruit with displaced apex as in H. incrassata and H. platysperma.

Vegetatively, there are also a number of parallels that can be made between the genera. G. infecunda resembles H. aenigma of Kangtroo Island and H. pulvinifera of New South Wales by maintaining its populations by root suckering alone. None of them produce fruits, and their pollen is sterile. G. banksii and G. pteridifolia both have forms ranging from prostrate to small trees, just as in H. prostrata. Variation in leaf structure within a species is a feature of a number of species in both genera, e.g. G. leptobotrys, G. ilicifolia, and H. varia.

With the documentation of the variation within Grevillea, the time has almost arrived for a cladistic analysis of the two genera to determine whether they are each truly monophyletic.

A number of chapters that are usually features of modem revisions have obviously not been undertaken because of the health of the author. I was personally sorry to see that there was no chapter on the history of the genus since I was very conscious that the ground trodden in preparation of the Hakea account had been well and truly explored previously by Don. However, the framework is now in place for studies on pollination, dispersal, reproductive biology, and evolutionary biology of the genus; and it is hoped that Bob Makinson, who has steered much of this book through its final stages, will undertake these. It is not quite clear just how much Bob's contribution has been, as the acknowledgements have all been done in first person singular, and nor am I quite sure whether the book's author should be cited as McGillivray or McGillivray & Makinson.

Not to mention the price of this book, would be remiss. It may be a product of the large size, prolific use of colour and small print run, but the figure quoted seems inordinately high and more in line with that for a limited-edition work. Unfortunately, it probably puts it beyond the reach of those "interested amateurs" for which the media release says it is a must, and it certainly makes it difficult to justify more than one copy per institution where budgets are tight.

It was a great pleasure to review this book. I am sure that the whole of the botanical community, particularly within Australia and at Kew where Don was very highly regarded during his term as Australian Botanical Liaison Officer, will derive a similar sense of satisfaction to see it. Despite all the difficulties he has had to face, Don, with Bob Makinson's help, has been able to produce a magnificent tome on the grevilleas.

References

Australian Network of Plant Conservation (1993) A Preliminary Listing of the National Endangered Species Collection.

Barker, W.R. (1989) Proteaceae. In: J.P. Jessop (ed.) A list of the vascular plants of South Australia (Edition 111). J. Adelaide Bot. Gard. 12: 8-9.

Makinson, R.0. & Olde, P.M. (1991) A new species of Grevillea (Proteaccae) from southwest Western Australia. Telopea 4: 351-5.

McGillivray, D.J. (1986) New Names in Grevillea (Proteaceae). Published and distributed by the author, Castle Hill, N.S.W.

Wrigley, J. & Fagg, M.A. (1989) Banksias, Waratahs and Grevilleas, and all other plants in the Australian Proteaceae family. Collins, Sydney.

Reviewer: Robyn Barker
Botanic Gardens of Adelaide and State Herbarium