Protea Repens Aurea, or Sugarbush, Family Proteaceae   Photo by the Author

Florida Wildflowers presents The Evolution of Proteaceae, in Flower and Leaf, by Harry Levin, several of whose valuable articles and whose unsurpassed photographs of flowers appear on our pages. The quality of his photographs of the Proteaceae are in keeping with the accuracy and attractiveness of those on his other pages. Dr. Levin, a chemical engineer who lives in Los Angeles, also lends to our pages groundbreaking essays on the Origin of the Angiosperm, the geological origin of New Zealand,  The Vast Geological Significance of a Fish  and The Dominance of the Dinosaur.

These and other essays are listed on the contents page.

"To biology and geology," writes Dr. Levin, "I bring a third viewpoint – that of the engineer. The engineer, in a best aspect of his profession, strives to resolve situations involving multivariables and their interactions. In ten essays, this engineer presents a startling reexamination of earth history. These essays provide accounts of hitherto unsuspected history of the late Paleozoic and the Mesozoic. They do so by interacting biological and geological events that occurred at the same time. The interweaving here  of geophysics and biophysics – both embracing climatology – brings out clarifying and sometimes incontrovertible evidence – content otherwise  obscure to, or hidden from, either one or the other of these disciplines when it acts alone."

The value of the Proteaceae family as an indicator of earth's history is as indisputable as the beauty of the flowers he depicts.

       Michael E. Abrams, Publisher
      Florida Wildflower pages   

By Harry Levin


The Proteaceae have a timeless beauty that brings to mind hillsides in cool sunshine flowered with red, yellow, and white ancestors of Protea (first frontispiece). They were, in the words of Marie Vogts (1), “present in Gondwanaland long before it began breaking up 300 million years ago.” The unbridled loveliness of Protea ennobles this planet this very day with that beauty.  

Dr. Harry Levin

The Proteaceae are among the most primitive families of the angiosperm, the flowering plant phylum of the plant kingdom. Carl Linnaeus, the father of taxonomy, is said to have been troubled by the multiformity of flowers of the Proteaceae.

Two frontispieces show in contrast the stark reality that troubled Linnaeus. They reveal startling differences in the morphology of inflorescences of genera of Proteaceae.

With age may come wisdom; and the Proteaceae give meaning to their message: “Earth’s history is written in her flowers.” Proteaceae are named after the god figure Proteus, and he could change his form.

Like Proteus, the Proteaceae retained the very essence of their nature while adapting to harsh environmental challenges. The specialized sex-organ identity of the Proteaceae has not changed in over 300 million years.

Befitting the everlasting Proteaceae, Shakespeare, in his wisdom, wrote:  “nothing ‘gainst Time’s scythe can make defense save breed;” and “Nor shall Death brag thou wand’rest in his shade,” (Sonnets 12 and 18). As treasures rare, ancient – and endangered – the Proteaceae urgently need thoughtful protection from the unrestricted encroachment of man and his works into their fragile habitats in Australia, Africa, and elsewhere.



Protea neriifolia variant

There are 136 species of Protea, all endemic to South and Central Africa. 
The flower head of Protea is an involucred flower cluster.

All photographs are the work of Dr. Levin
and are protected by copyright.  Inquiries
about the article and its photographs
should be made to Dr. Levin whose
email address appears above.


Second Frontispiece

Flowers of the Firewheel Tree

Wheel-spoke flowers of the Australian firewheel tree, Stenocarpus
sinuatus, at mag. x 4. A style emerges from an immature flower.

On each style is a superior positioned (brownish white) ovary.
Inside a "tennis ball" at the top of each flower nest 4 anthers and
an immature stigma.

At the bases are four black nectar glands, slightly visible.

The firewheel is pollintated by the brush-tongued rainbow lorikeet,
Trichoglossus haematodus, in reward for nectar.



The plant family Proteaceae represents the history of the angiosperm phylum simply by telling their own story. Their flowers were one of the earliest experiments of the angiosperms in bisexual floral structuring. Alive today, they have no close relatives. Odd and isolated, they have been referred to as “bizarre.”
Current doctrine holds that the Proteaceae, as members of the angiosperm phylum, originated in the Cretaceous – perhaps because fossil flower records of the late Paleozoic and the early Mesozoic are almost nonexistent. Fortunately, however, an independent historical record is kept within the live flowers of the Proteaceae themselves. These flowers carry within themselves a unique and unmistakable sex organ identity unchanged over vast intervals of time and distance. 
In hypothesis, the Proteaceae originated in the late Paleozoic, 360 to 250 million years ago  –  before the coming of the dinosaurs. The last 50 million years of that era were marked by the Permo-Carboniferous Ice Age (also termed the Gondwanaland Ice Age) with its pervasive ice fields that covered much of the southern hemisphere. Today the Proteaceae are distributed over the southern hemisphere in remarkably strange ways that can be explained by the impact of that epochal glaciation and the drift of continents and smaller continental blocks.  The geographic distribution of Proteaceae genera is inexplicable under the doctrine of Cretaceous origin. 
Botanists have classified the Proteaceae into two subfamilies and fourteen tribes. The two subfamilies are the Proteoideae and the Grevilleoideae, referred to here simply as P-oides and G-oides. A third frontispiece chart shows the present-day distribution of P-oides and G-oides over the world.
For ready distinction, here Proteaceae genera native to Australia are also named Austrops; those native to Africa, Afrops. For example, a P-oide genus native to Australia is an Austrop P-oide; a P-oide genus native to Africa is an Afrop P-oide. No Austrop is native to Africa; no Afrop is native to Australia. 


Present World Distribution of Proteaceae

 Chart is a composite of sources

P-oides (Proteoideae)

G-oides (Grevilleoideae)

P-oides and G-oides

Regions of Dense Distribution


       C. Venkata Rao, Proteaceae p. 3 (1971)
       L.A.S. Johnson and B.G. Briggs,
       Bot. J. Linn. Soc.  70  83-182 (1975)


With the aid of photography, this essay demonstrates the remarkable similarity, hence constancy, of the reproductive structures of the flowers of the Proteaceae of Australia and Africa. The similar, yet unique sex organs of the flowers of Australian and African genera speak of a land passage long ago traveled by Proteaceae between Australia and Africa. This sameness of floral elements has been preserved to the present time despite the remarkable chronological separation of several hundreds of millions
of years and the interposition of the Indian Ocean.
The leaves of present-day Proteaceae, within genera, display a sequence of evolutionary curtailment of form and structure in accord with the premise that the foliate structure of the Proteaceae simplified defensively in adapting to the gradual but varied encroachment of the Permo-Carboniferous Ice Age    of 300 to 250 million years ago. Several leaf form sequences will be presented by photos in support of the premise. 

Banksia ericifolia
Consider first Banksia ericifolia, an Austrop G-oide shrub or tree, which may grow to a height of about 3.5 meters. It is commonly known as the heath banksias, and it is found in large numbers today in Victoria, Australia.
Banksia ericifolia is chosen because it bears the imprint of the Permo- Carboniferous Ice Age. It is a survivor of the last glacier foray into New South Wales (250 million years ago) and is a living example of how the icy cold of 300 to 250 million years ago altered the Proteaceae in reach.  B. ericifolia came as close to the glaciers of New South Wales as nature’s chemistry would allow. Ice molded it into an entity hard and frugal. Its very frugality caused it to husband only the essentials of growth and reproduction. Among these are the basic flower characteristics that unite the Austrops of Australia and the Afrops of Africa, while setting them off from all other flowering plants.  
B. ericifolia’s flowers exemplify “evolutionary simplification”. Indeed, evolution does not perforce lead to ever increasing complexity. It does at times retrench or regress in form or function. Thus it may enable a species to survive in an increasingly hostile envionment.                  
Figure 1 shows a flower spike of B. ericifolia. It emerges upward among needle-like leaves.  It is about 14 cm. tall and looks like a small corn cob from the distance.


This flower spike is at an early stage of reproduction and bears about 1000 flowers. In magnification, Figure 2 shows immature flowers on the spike. The flowers are in pairs  –  a feature that distinguishes these and other G-oides from P-oides.
A pair of flowers illustrates (in Figure 3) the location of basic flower parts.  There is the perianth, which looks like a musical quarter note: a thick grayish stem with an angled cup at the upper end. There is the style, a bent conduit, a female part of the flower. Characteristically, at this early stage of maturation, the style has not yet entirely escaped the perianth cup. At the head of the style, a tiny knob, termed a “pollen presenter,” remains within the perianth cup.  The style of B. ericifolia is like a wicker, hard and wiry, forged by the cold.
Are these flowers?  Yes, but they are hardly recognized as such except by the trained eye. The perianth, stark as it is, is really a flower tube, the outer  part of the flower. And these flowers are bisexual.  Within their frugal   apparatus, hidden and protected from the cold, are all the sex organs necessary for reproduction of the plant. The male sex organs, called  “the androecium,” consist only of four anthers joined to the inside wall of each of four segments that form the angled cup of the perianth. The anthers apparently are without filaments. They are mature and are producing pollen.
The female sex organs, called in sum “the gynoecium,” consist of the style with a minute ovary at its lower end and the stigma at its upper end, positioned at the very tip of the pollen presenter.  At this early stage shown in Figures 2 and 3, the pollen presenter, nestled (unseen) within the cup of the perianth, is closely surrounded by the four anthers.  The stigma itself is not yet receptive to fertilization. The male sexual organs become functional before the female.
In the next stage of maturation, the style will “flip out” of the perianth cup. The flower then will be said to be “laid open”, and the pollen presenters will be covered with pollen. Figure 4 in magnification shows a flower spike for  which the flip-out is under way. The flowers, in a gradual, orderly manner, are being laid open from the bottom to the top of the spike. Here the pollen  presenters are barely visible atop the open styles. They are minute among the Proteaceae.


Figure 1:  This is a flower spike of B. ericifolia, emerging upward among
needle-like leaves.  About 14 cm. tall, it resembles a small corn cob from a distance.


Figure 2:  Magnified, immature flowers on the spike of B. ericifolia.  The flowers
are in pairs, a feature that distinguishes these and other G-oides from P-oides.


Figure 3: Banksia ericifolia immature plucked flowers, mag. x 6.5.
Compare with frontispiece.


Figure 4:  Banksia ericifolia styles "flip out" as maturation
advances from bottom to top of spike.


Most significantly, the floral features of the G-oide B.ericifolia are common not only to Austrops but also to Afrops, with the exception of a few unisexual genera, which are perhaps atavists of ancient seed ferns. In particular, the perianth/style relationship is the readily recognized signature, a hallmark, of both Austrops and Afrops in form and function. The austere simplicity of the flower of B.ericifolia (in defense against the ice) can best be appreciated by comparison with the more intricate and elaborate flowers of selected Afrops and of other Austrops to follow. But first, the leaves.
Intimations of an Icy Past among the Leaves
The genus Banksia attests to the premise that Proteaceae leaves, in form and structure, reflect various degrees of adaptation to the glacial conditions of the Permo-Carboniferous Ice Age. Even today, they range from the primal rainforest large, compound leaves to the needle-like leaves of B. ericifolia.
Accordingly, a botanical comparator, a “leaf form sequence,” of Banksiae is presented to illustrate both effect and degree of ice field encroachment.  Banksia ericifolia, Banksia spinulosa, Banksia integrifolia, and Banksia burdettii are shown in Figures 1, 5, 6, and 7, respectively, in sequence of increased leaf elaboration and presumably of increased distance from ice field. While this paper does not cover the full range of the change for Banksia, it does point out that those species that might once have stood farther away from the ice’s edge have broader and more elaborated leaves than Banksia ericifolia. Those other Banksiae can be described as progressively less austere, or more expansive. The premise of simplification in proximity to ice is supported not only by Banksiae, but is also evident, as will be shown, in the Austrop Grevillea, the largest genus of Proteaceae. 
The term “ericifolia” means heather leaf. The short needle-shaped leaves of B. ericifolia are like those on the heather of the blustery moor and on fir trees and other cold-adapted conifers. The Afrop P-oides show a parallel example of leaf simplification in Leucadendron ericifolium. It is also  “heather-leafed;” and its antecedents too are surmised to have faced the bitter chill at the ice’s edge some 300 to 250 million years ago.
Along with other changes in leaf morphology, the leaves of Banksiae have evolved a whorl pattern, which is most in evidence on the densely needled limbs of B. ericifolia. The whorl pattern very likely evolved during the ice age, because of a need to capture ice-melting sunlight more effectively. 


Figure 5: Banksia spinulosa v cunningham mature flower spike


Figure 6: Banksia integrifolia, showing increased leaf elaboration over Figures 1 and 5.


Figure 7: Banksia burdettii shows the most leaf elaboration of Figures 1,5,6 and 7,
presumably meaning this plant was further away from the ice fields than others.


Furthermore, like many other Proteaceae, the above Banksiae have hard, leathery leaves. However, this hard-leaf (sclerophyllic) development may have been less a response to the Gondwanaland Ice Age than an adaptation later to semi-arid, sandy habitats, poor in mineral content - - a secondary evolutionary effect that followed the ice age in both Australia and Africa. 
Leucospermum cordifolium, an Afrop P-oide
Pointing now to the Afrops, consider first the genus Leucospermum, among the best known of the Proteaceae. Leucospermum is commonly called a pincushion plant, and, indeed, it looks like a pincushion after its long, stiff styles have flipped out.  About 90% of all Leucosperma grow today among other woody shrubs on sandy hillsides and in fields termed “fynbos” within “the Cape Folded Mountain Region” of South Africa that fronts the Indian Ocean. The mature flower heads of Leucosperma are beautiful (Figures 8 and 9). They range in color from chartreuse to deep orange, from pink to crimson. Figure 10 shows three newly budded flower heads of a Leucospermum hybrid nestled among leathery leaves.
In Figure 11, an immature Leucospermum cordifolium flower head displays long, stout styles with top-shaped pollen presenters.  The flower head clearly shows the stigmas atop the pollen presenters. Although these stigmas have taken on pollen, they may not yet be receptive to pollination.
In this immature L.cordifolium, the styles are flipping out, starting at the periphery and advancing toward the center, in a gradual sequential manner (reminiscent of the gradual advance of the flipped out styles of Banksia ericifolia in Figure 4). The less mature inner flowers are not yet laid out. Like B. ericifolia, they show a reentrant style. The pollen presenter at the far end of each “unflipped” style is surrounded by the four anthers attached  within the perianth cup from which it will spring. A tiny superior ovary is present at the near end of the style. The anthers, styles, stigmas, pollen presenters, and ovaries resemble closely the sex organs of B.ericifolia.
The similar, yet unique sex organs of the flowers of an Austrop G-oide (B. ericifolia) and an Afrop P-oide (L. cordifolium) tell of a land passage long ago traveled by Proteaceae between Australia and Africa. This remarkable sameness of floral elements has been preserved to the present time despite three hundred million years of separation and the vast interposition of the Indian Ocean.


Figure 8:  Leucospermum, an Afrop P-oide, is presented in Figures 8 through  13.
It grows mainly in the sandy hills of the "Cape Folded Mountain Region" of South Africa,
facing the Indian Ocean. There are 40 species. At top is Leucospermum "Veldfire"
maturing flowerhead, at mag. x 1.7.


Figure 9:  Leucospermum cordifolium maturing
flower head,
at mag. x 1.2.


Figure 10: Leucospermum hybrid flower heads, newly sprung,
at mag. x 1.6. The leaves are leathery




Figure 11: L. cordifolium at several stages of maturity, at  mag. x 3. 
Note the open stigmas atop the pollen presenters.  At periphery,
mature flowers have flipped out, central flowers are still immature.


A Strikingly Disparate Similarity

The sameness of Austrop and Afrop floral elements is wonderfully told by two Proteaceae that are extremely different both in form and in location. One is a ground-hugging Afrop shrub, Leucospermum gerrardii. The other is a massive, towering Austrop tree, Grevillea robusta. 
L. gerrardii is a leathery-leafed mat shrub found in the mountainous regions of the eastern Transvaal, where the rainfall is plentiful in summer. Its floral tint changes from yellow (in Figure 12) to red (in Figures 13) in going from youth to maturity. Grevillea robusta, on the other hand, is a leafy tree, an evergreen, mainly indigenous to Southwestern Australia. Termed a silk oak, it often grows to more than 20 meters in height and is about 1.6 meters in girth. Several months of the year, this treeis conspicuously yellow with flowers. The flowers grow only on the upper part of the horizontally inclined flower spike; and, characteristic of a G-oide, they can be seen in pairs in
Figure 14. 
Most surprising is one detail. The flowers of both the Afrop shrub (Figures 13) and the Austrop tree (Figure 15) display an inverted red- colored underside of the perianth, like a four-striped red ribbon. In both flowers, the perianth can be seen splitting lengthwise into four characteristic segments, while the styles are in process of flipping out. In immaturity, the pollen presenters of the Afrop shrub and the Austrop tree are sheathed in their perianth cups (Figures 12 and 14, respectively). Best seen in Figure 12, the perianths of L. gerrardii are white-haired  –  just as are the perianths of Austrop Banksia burdetti in Figure 7. The L. gerrardi flower head is shown again at a later stage (Figure 13) where almost all of its conical pollen presenters are flipped out and covered with yellow pollen. 
These idiomorphic similarities of disparate, distant Australian and African species bear important witness that the Proteaceae ranged Gondwanaland from Australia to Indo-Madagascar to Africa to South America prior to the Gondwanaland Ice Age 300 million years ago.  Grevillea robusta displays a style (Figure 16) as it was just starting to hump its way out of a perianth while attached to it at both ends.  A more mature flower spike is shown (Figure 17), just after its (deciduous) perianth segments had been blown away. The female sex organs were all there, bare and alone, starkly mounted on stems, offering a unique epitome of proteaceous parts: the minute superior ovaries, the styles, and the minute pollen presenters with stigmas  –  parts that are common to both Austrop and Afrop.    


Figure 12: Leucospermum gerrardii, an Afrop P-oide mat shrub,

showing immature flower head. The styles are sheathed in
white-haired perianths (as are the styles of Austrop G-oide
Banksia burdettii in Figure 7).


Figure 13: L. gerrardii, showing perianths, each with four inverted
("turned out") red striped segments. Observe that the pollen
presenters are coated with pollen.


Figure 14: Grevillea robusta, an Austrop G-oide tree, showing immature
flower spike at mag. x 5.  Flowers are in pairs, on upper side of spike only.


Figure 15: Grevillea robusta, immature flower, showing perianth

with four "turned out" red-striped segments at mat. x 9.  Compare with Figure 13.


Figure 16: Grevillea robusta, immature flower, with style just
starting to hump its way out of the perianth, at mag. x 6.5.


Figure 17: G. robusta mature flower spike devoid of (deciduous) perianths.

Each bare flower shows a unique summary of its female parts: the minute
(superior) ovary, the style, and the pollen presenter with stigma.


Ancestral Voices
Picture the Proteaceae during the Carboniferous already spread across Gondwanaland, initially native to cool rainforests. There, the first flowering plants had surely inherited fern-like leaves from fern ancestors. At first, in continuity, they consociated with the seed ferns and other ferns, which had reached their heyday. At that time the Gondwanaland flora from one end to the other was dominated by glossipterids (seed ferns that had tongue-shaped fronds with large midribs). Even today at elevated heights on the volcanic soil of half-million-year-old Hawaii, ferns exert an awesome influence. Hapu tree ferns and uluhe mat ferns dominate. With their enormous light- excluding fronds, they blanket the impenetrable forest floor with darkness, as their ancestors likely did during the Carboniferous. It seems plausible that the Proteaceae gradually spread out, or were crowded out by the ferns, into less hospitable  –  open and semi-arid  –  environments. The towering G. robusta trees were probably among the last to depart the cooling rainforests.
Morphological Retrenchment
To varying degrees, ancestral fern characteristics are conserved among the Proteaceae. Ronald Melville reported incipient transitions from seed ferns to angiosperms in 1960 (2) and in later papers. “The primary diversification of the pre-angiosperm stock appears to have taken place,” he inferred, “ . . . during the late Carboniferous or early Permian. Many angiosperm lineages must date back to this period as distinct lines of evolution . . .”   He noted that the parallel veining found in the leaves of Proteaceae and in other primitive plants could have evolved from Gangamopteris, an extremely ancient (Devonian) Gondwanaland seed fern (without a large frond midrib).
The leaves of  G. robusta in Figures 18 and 19 are offset-opposite, long, broad, comparatively soft, thin, and deeply divided (in contrast to the  whorled needles of Banksia ericifolia in Figure 1). Species like G. robusta show, “primitive morphological characters” when they have large compound leaves with expanded leaflets, according to Venkata Rao, 1971 (3). Large, compound leaves indicate a mainly frost-free past.



The leaves of G. robusta show a fern-like pattern and a trace of parallel veining; and, indeed, these leaves appear to resemble the leaf patterns of the spleenworts, the woodsias, the spear-leaved fern, and other ferns alive today.  Furthermore, parallel veining is manifest in the leaves of Banksia burdettii (Figure 7). And here too appears a resemblance to the leaves of the fern genus Pteris, with their slender shape and large frond midrib.
In premise, the Permo-Carboniferous Ice Age eroded much of the ancestral parallel veining, starting with the approach of the ice 300 million years ago. To argue the deletion of parallel veining, a leaf form sequence for Banksiae is cited once again, starting with the parallel veining in evidence in Banksia burdettii and following in sequence with the leaf of Banksia speciosa, now introduced as Figure 20, to represent an early incursion into parallel veining. B.speciosa is a large shrub, endemic to Australian near-coastal sand dunes.

Examining a magnified undersurface of its leaf, the parallel veining is shown starting outward at right angles to the midrib (as in B. burdettii), but then, converging to a point in each segment. Moreover, with the intrusion of the ice age, this leaf lost its serrations (so evident in B. burdettii); and it became deeply divided and smooth. Farther into icy regions, the leaf of B. integrifolia is smooth and linear (Figure 6). And in the shadow of glaciers in New South Wales, then well within the Antarctic Circle, B.ericifolia (Figure 1) had evolved needles.
And Banksiae are not alone in transition from large leaves to needles during the Permo-Carboniferous Ice Age. Grevilleae too, in Australia, simplified their leaves. Indeed, among the 273 species of Grevilleae, leaf form sequences are readily observable that denote simplification. For example, far away from the ice were the long, broad leaves of G. robusta in Figure 18. Closer in were smaller leaves represented by the hybrid Grevillea “Robyn Gordon,” (Figure 21), which bear resemblance to those leaves of G. robusta. And ever closer were the deeply parted leaves of Grevillea boongala (or spinebill), in Figure 22. They resemble the segmented leaves of B. speciosa in Figure 20. In apparent remarkable convergence, the hybrid Grevillea “Red Glow” (Figure 23) shares the needle badge of nearness with Banksia ericifolia (Figure 1)  –  both having faced up to the Gondwanaland ice and survived. 
In summary, the leaves of present-day Proteaceae, within the two genera examined, display a sequence of evolutionary curtailment of form and structure apparently in adaptation to gradual but varied encroachments of icefields. Before the Permo-Carboniferous Ice Age, large compound leaves with (seed-fern-remanent) parallel veining were characteristic of Proteaceae. However, during that ice age, leaf simplification occurred within genera, from large compound leaves to needles (at the extreme). 



Figure 18: G. robusta leaf pattern, suggestive of  fern frond, mag x 0.7


Figure 19: G. robusta with indications of parallel venation, mag x. 1.3


Figure 20: Banksia speciosa, underside of leaf, mag. x 4.7, at right. The veining
starts as parallel, but comes to a point. Left photo shows segmented leaves at different ages.


Figure 21: Hybrid shrub Grevillea "Robyn Gordon" leaf at mag. 1.7.
Note resemblance to G. robusta leaf in Figure 19.


Fig. 22: Grevillea boongala (or spinebill). Deeply parted leaves
show inroads of glaciation. Compare to segmented leaves of B. speciosa, Figure 20.


Figure 23: Grevillea "Red Glow" needles, mag. x. 2,
indicating extreme adaptation to glaciation.


Yet even today, some species of Proteaceae that were less exposed to ancient cold, have large leaves with deeply divided or expanded leaflets that are, as Venkata Rao noted (3), primitive characters of Proteaceae. Moreover, evidence of parallel veining, associated with seed fern ancestry, remains in species with the most frost-free pasts.  
The Nectar Factor
The perianth of most Afrops and Austrops produces copious nectar that lures insects, birds, and mammals to pollinate flowers. The perianth is both the nectar source and its reservoir. On the inside of its tube wall, below the enclosed tiny ovary, are four scale-like glands (collectively a nectary), which fill the inside base of the perianth with nectar. The perianth’s nectar reservoir is in slight view in the second frontispiece.
Nectar reservoirs are in the flowers of most Afrop and Austrop shrubs and trees and are essential to their reproduction. Over the past 360 million years, they undoubtedly have had a key and even crucial role in the co-evolution of a wide variety of pollination-capable insects, as well as other fauna. Insect and angiosperm early adapted to each other’s needs for mutual benefit. The survival of the Proteaceae tothis present day is due largely to the beneficial exchanges of pollination and reward. The impact of these exchanges on faunal evolution is discussed in companion essays.                                                                 
The Flower That Blooms This Day
Like the mythical god Proteus, the Proteaceae come in a wide variety of shapes and sizes; yet they present unique constancy of reproductive organs identical in essential form and function. Their flower heads range from gaunt to lovely, and the latter quality can be savored in Grevillea banksii (Figures 24 and 25) and Grevillea longistyla (Figure 28). An elaborately convoluted perianth is displayed by G. longistyla in Figure 29. Both G. banksii (Figure 26) and G. longistyla (Figure 30) clearly reveal the uniquely proteaceous anther-to-perianth cup attachment. Immature G. banksii fruit follicles (with one or two seeds) are shown in both Figure 24 and 27. The ornate flowers of  G. longistyla tell that its antecedents had eluded the intense chill of the Permo-Carboniferous Ice Age. Contrast once again the gaunt Banksia ericifolia flowers in Figure 2. 



Figure 24:  This is Grevillea banksii "Forsters," flower spike

(and in the background, immature fruit follicles).


Figure 25: Grevillea banksii flowers in various stages of maturity, mag. x 3


Figure 26: Grevillea banksii perianth cup after release of style

at mag. x 7. Note the anthers within the cup.


Figure 27: Immature fruit and follicles of Grevillea banksii.


Figure 28: Grevillea longistyla, ornately convoluted perianths, mag. x 3.
Compare with simplified perianths of Banksia ericifolia in Figures 2 and 3.


Figure 29: G. longistyla flowers show bilateral symmetry of perianth, at mag. x 5.

On each side of emerging style, an inner perinth segment is nested within an outer one.


Figure 30: G. longistyla, with "curled back" perianth after style release.
It shows three of its four anthers adnate to perianth segments at mag. x 5.5.


By reason of the angiosperm invention of the bisexual flower, the Proteacea found a stable independence, an enhanced ability to diversify, and a greater freedom to roam far and wide. The present worldwide distribution of Proteaceae (shown in third frontispiece) is sometimes termed “enigmatic” and is, indeed, wondrous. It is a remarkable end product of the Permo- Carboniferous Ice Age and the breakaway of a large landmass from Australia, coupled with the gradual drifting apart of the component  Gondwanaland continents. The unique reproductive organ hallmark of the Proteaceae and their enigmatic world-wide distribution strongly affirm that the Proteaceae inhabited the entire length of Gondwanaland, from Australia to South America, more than 300 million years ago.
1) Vogts, M., Proteaceae, C. Struik, Cape Town, South Africa, 1982.
2) Melville, R., Glossipteridae, Angiospermidae, and the evidence of  
    angiosperm’s origin, Bull. J. Linn. Soc., 86,  279-323 (1983).
3) Rao, C.V., Botanical Monograph No. 6 Proteaceae, Council of Scientific  
    and Industrial Research, New Delhi, 1971.
4) Tarling, D.H. and Tarling, M.P., Continental Drift, a Study of the Earth’s  
    Moving  Surface, G. Bell and Sons, London, 1971.
5) Metcalfe, I., “Origin and assembly of South-east Asian continental 
     terranes,” 101-118, in Gondwana and Tethys, eds. M.G. Audley-
     Charles and A. Hallam, Geological Society, Oxford Press, 1988.