Special Western Myrtles

The family Myrtaceae is one of the most conspicuous families in Australia, and is also well-represented in South America, but is also found, albeit less profusely, throughout much of the rest of the world, including Europe where the Common Myrtle Myrtus communis gave its name to the family.

In Australia Eucalyptus, Callistemon and Leptospermum are the largest genera and the most familiar, but there are some 1500 species and 70 genera here, representing about half of the world's total for both. (I have seen some recent figures suggesting twice the number of species and less genera, but without exploring the basis of this I suspect it represents a current trend in botanical taxonomy towards massive 'lumping', the helpfulness of which in terms of understanding more subtle levels of relationships I've questioned before.)

However the year is just getting into gear and I'm not inclined to be too philosophical or disputatious today. Rather I'd like to introduce and celebrate some Myrtaceous genera which are only (or nearly only) found in Western Australia, famous for its amazingly rich flora and high level of endemics. Some of these beauties may be new to you if you're not familiar with WA, but in any case I hope you enjoy them. To avoid suggestions of favouritism I'm simply going to introduce the genera in alphabetical order; bear in mind that this is nowhere near the full number of such genera. (Bear in mind too that plant taxonomy is a rapidly changing field, and it may be that some of the plants that follow have in recent times been offered different names - you'll readily find them under the names I use here though, and I've tried, as ever, to keep up to date.)

      Actinodium

This is a slightly contentious genus to begin with, because though there has traditionally only been one species recognised, there seems to be a growing opinion that a second one, still unnamed, has long been confused with it. The name refers to rays, for the flowers' superficial resemblance to daisies, also reflected in the common names.

Swamp Daisy Actinodium cunninghamii, Stirling Ranges NP.

Albany Daisy A. sp., also from the Stirling Ranges.
I have based my identification on the larger paler flowers, but I'm happy to be corrected, as ever.

      Balaustion

Another very small genus, comprising just one species (but see under Cheyniana below). Like the Actinodium, the flowers don't immediately remind an eastern-stater of the family members with which we're familiar.

Native Pomegranate B. pulcherrimum, east of Hyden.
The genus name cames from the Greek for a pomegranate flower.

      Beaufortia

A larger genus, restricted to the south-west, of some 22 species closely related to the widespread Melaleuca, as well as some similar WA endemic genera. Needless to say there are some who would lump them all into Melaleuca, but this doesn't seem to have gathered much traction. Beaufortia was named by the great Scottish botanist Robert Brown to honour the Duchess of Beaufort, Mary Somerset; she is often described as a botanist, but is better thought of, I believe, as an assiduous horticulturist. She died in 1715, nearly 100 years before Brown's naming.

Pink Bottlebrush B. schauerii, Stirling Ranges NP.
'Bottlebrush' is commonly used for the genus, though it is better-known as the common name for Callistemon
elsewhere in Australia. Johannes Schauer was a German botanist with an interest in Australian plants;
as far as I can tell he named this for himself, which would be a most irregular thing to have done.

Sand or Kalbarri Bottlebrush B. aestiva, Kalbarri NP.
This northern sandplain species also comes in a red form.
(Scan of an old and somewhat faded slide - sorry.)

      Calothamnus

Probably the largest WA endemic Myrtaceous genus, with some 40 species (but see Verticordia below), generally referred to as one-sided bottlebrushes, netbushes or clawflowers. The claws comprise long red stamens in four or five clusters, protruding from a short tube of sepals; the petals are tiny or absent. Often the flowers appear on one side of the stem. The somewhat unimaginative (though a propos) name simply means 'beautiful bush'.

Calothamnus blepharospermus, Kalbarri NP.
The flower characteristics described above are shown here, along with the typical cylindrical leaves.
blepharospermus means 'eyelash seed'...

Common Netbush Calothamnus quadrifidus, Christmas Rock, east of Perth.
This widespread species is especially known as One-sided Bottlebrush, for the obvious reason.

      Chamaelaucium

There are 14 species recognised of this endemic genus, by far the best known of which is Geraldton Wax G. uncinatum, which is widely cultivated on both sides of the Nullabor. They have open teatree-like flowers with waxy petals. The somewhat mysterious name (appended by French botanist René Desfontaines without explanation) apparently refers to the shape of the base of the flower as resembling a bishop's mitre!

Geraldton Wax, Badgingarra NR, with pollinating wasp.
These northern sandplains are their natural habitat.

      Cheyniana

Another tricky one; the genus was only described in 2009, to incorporate just two species, one formerly placed in Balaustion (see above), the other being an unnamed species formerly described as a Baeckea. (I wouldn't want to be working on the WA Myrtaceae, though it would guarantee a life's work!)

Bush Pomegranate Cheyniana (formerly Balaustion) microphylla, Pindar.
This one is found in a small area of the northern sandplains and is threatened by clearing for agriculture.

      Eremaea

A genus of 14 species closely related to Calothamnus. The name means 'solitary' (as in hermit, and ultimately from the word for desert), in apparent reference to the relative few clustered flowers at the tips of branches. They can be a quite prominent part of the heathlands.

E. beaufortioides, Moore River NP, north of Perth.
Orange is not a common colour in Australian plants.

Violet Eremaea V. violacea, Yandin Hill Lookout, north of Perth.
A lovely low sprawling shrub.

       Hypocalymma

A genus of at least 23 species (plus some still unnamed) which have generally been known as myrtles since species were introduced to England in the 1840s, where their resemblance to the European myrtle was noted. Some are widely cultivated for their profuse flowers.

White Myrtle H. angustifolium, John Forrest NP, Darling Ranges.
One might reasonably think this an odd common name, but the flowers start white and darken with age.
This is one of those introduced early to English gardens.

X. xanthopetalum, Moore River NP, north of Perth.
Yellow is an unusual colour for this genus.

      Verticordia

Technically I shouldn't be including this here, as in addition to the 100 or so WA species, two are also found in the Northern Territory. However it's too beautiful a plant to exclude on a technicality, it's one of my favourites, and how could I not include a genus whose name means 'heart turner'?! Featherflower is an oft-used common name. Anyway, let's enjoy some to end today's offering.

Scarlet Featherflower V. grandis, Gathercole Nature Reserve near Wongan Hills, above and below.
An especially large-flowered species, quite dramatic.

 

V. insignis, John Forrest NP. The name, perhaps counter-intuitively, means 'remarkable' or 'decorative'.

Woolly Featherflower V. monadelpha, Kalbarri NP.

V. chrysanthella, near Ravensthorpe.
Despite being widespread this species was only described (by the doyen of WA botanists, Alex George)
in 1991; prior to that it had been confused with the larger V. chrysantha.

And that's probably enough for one day. I hope you've enjoyed these glories as much as I have. But, as ever there's no substitute for going to see them for yourself...

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