On the Proteaceae-the evolution and classification of a southern family*

Abstract

A scheme of phylogeny in the Proteaceae is derived from analysis of new and previously available data on morphological, anatomical and chromosomal characters. The probable attributes of a common ancestor are indicated and it is concluded that the family has no close relatives, although it possibly diverged early from the Rosiflorean line. Chromosomal evolution has been complex, with early polyploidy, repeated dysploid reductions and great change in chromosome size, from a probable base of x = 7. Habit, wood anatomy, leaf form and sequence, chemical features, inflorescences, pollination and pericarp anatomy are discussed in relation to adaptation, phylogeny, parallelism and convergence. Distribution is analysed ecogeographically and in relation to the fossil record and chronology of continental movement. Ancestors of major groups may have differentiated before the break‐up of Gondwanaland. Early members of almost all tribes were probably trees of mesothermic closed forests; xeromorphic characters found in many modern genera are secondary and of multiple origin in Australia, South Africa, New Caledonia and to a lesser degree in South America. The Proteaceae, with 75 genera, are divided into 5 subfamilies (3 new) comprising 14 tribes, further subdivided into 33 units of subtribal level. New genera described are Toronia, Acidonia, Pycnonia, Triunia, Malagasia, Athertonia, Virotia, Floydia.

The cytotaxonomy of four Tasmanian genera of Proteaceae

“…The finding of 2n=28 (x=14) for O. diversifolia from localities around Hobart is entirely consistent with other data for Orites, indeed for the tribe Oriteae including Neorites, all x=14 (Venkata Rao 1957a, b;Johnson and Briggs 1975). This discounts the earlier report of n=15 for the species from near Hobart and in this respect O. diversifolia does not differ from other Orites species.…”

“…The few but large chromosomes of Bellendena possibly constitute an advanced karyotype in Proteaceae (Johnson and Briggs 1975;White 1978;James 1981;Weston 1994), perhaps by a process of amalgamating smaller but more numerous chromosomes similar to those of the previous three taxa. However, Bellendena is now placed in the monotypic subfamily Bellendenoideae (Weston 1995) and is suggested to be the sister group to all other Proteaceae (Douglas pers.…”

Inflorescence and floral development of Carnarvonia (Proteaceae)

“…Originally, the genus was placed in Grevilleoideae (Engler 1889) based on the dehiscent follicle and winged seeds and in the tribe Macadamieae by Venkata Rao (1971) based on the regular flowers. Currently, the genus is placed in a subfamily of its own, Carnarvonioideae (Johnson & Briggs 1975) on the basis of several unique characters like the loosely organized racemopaniculate inflorescence, fruit structure, 'partly digitate, partly pinnate and partly first-degree, partly second-degree division of the leaves' (Johnson & Briggs 1975, p. 106--107), and several hypothetically independently derived characters or homoplasies such as the absence of hypogynous glands, and the the presence of two hemitropous ovules. Carnarvonia is also excluded from Grevilleoideae due to the fact that it lacks the grevilleoid flower pair condition (two flowers subtended by a common bract along the main axis; Johnson & Briggs 1975).…”

“…Carnarvonia is also excluded from Grevilleoideae due to the fact that it lacks the grevilleoid flower pair condition (two flowers subtended by a common bract along the main axis; Johnson & Briggs 1975). In Johnson & Briggs (1975), Carnarvonia is hypothesized to be derived from a common ancestor of Grevilleoideae.…”

“…Diverse forms of flowers and inflorescences are necessarily the products of differences in ontogenetic processes within each system. The hypothesized relationship of Carnarvonia as having shared a common ancestor with a taxon within Grevilleoideae (Engler 1889, Venkata Rao 1971 or as having a common ancestor with Grevilleoideae (Johnson & Briggs 1975) implies a divergence of developmental patterns in inflorescence construction that is either derived from the basic 'grevilleoid raceme' and flower pair condition found within Grevilleoideae in the former or from a 'common-groundplan' with Grevilleoideae in the latter. Within a developmental comparative context, the specific processes that result in a particular or novel morphology can be assessed (Wardlaw 1952, Fink 1982.…”