Conospermum floribundum - Proteaceae

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Conospermum floribundum - Proteaceae

This species is more commonly found between Albany and Ravensthorpe and so normally outside my study area, but I encountered several plants in the Lake Tay region around 80 km NE of Ravensthorpe and 150 km NW of Esperance. They were a good match to the published description, except the leaves were up to 1.5 cm (5/8”) longer and the flowers were pinkish rather than white, except for the (described) blue apices.

By way of explanation, the enlarged flower photo above and taken in August (mature flowering period is from September to December), was from a juvenile plant where the flower spikes had not yet developed. Plants were to 90 cm (3’) in height and were growing in deep yellow sand as a component of mallee heath.

Conospermum floribundum is closely related to Conospermum distichum, which has a considerable distribution overlap west of Esperance. It however differs by the flowers having longer and more congested white hairs than C. floribundum, plus the upper blue lip is quite glabrous (without hair), as are the leaves. Visually, flowering shrubs of C. floribundum tend to be more open and spreading, whereas C. distichum are usually compact and resemble blue/white cushions.


Conospermum is part of the large and highly diverse Proteaceae family.


Reference:
Conospermum
By E.M.Bennett
Flora of Australia
Volumes 16 (1995), 17A (2000) and 17B (1999).

Smokebush - Conospermum leianthum

There are two subspecies of this Smokebush in the Esperance region and although they overlap, subsp. leianthum occurs mainly to the north and west of Esperance, whereas the other subspecies, subsp. orientale is (apart from a the odd western colony) mainly found to the NE and east of the township. The main difference between them is with the length of the leaves and the density of the flower clusters. Subsp. leianthum has leaves that are 10 cm (4") or more in length, with an open inflorescence, whereas the leaves of subsp. orientale are less than 10 cm in length and the inflorescence more compact. As they can appear very similar when viewed separately, I have restructured this post to include both subspecies to enable a direct comparison.

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Conospermum leianthum subsp. orientale

This is the most common subspecies to the east of Esperance and can be found in deep sandy soil or shallow sand overlying gravel, favouring soil disturbance along roadsides or the aftermath of bushfires, when competing tall vegetation has been reduced. However they blend into surrounding vegetation when not in flower and are easily overlooked. During the first few years when the shrub is less than a metre in height, it is a reasonably compact rounded shrub, but as it matures, the upright branches begin to spread and often bend down to the ground with just the tips turning upright.

The numerous cream/white flowers of both subspecies are less than a centimetre (1/4") in length, but flower over several weeks and can be quite showy. Like other local Smokebush species, they are pollinated by insects, attracted by a subtle sweet fragrance. Flowering of subsp. orientale is usually from September to December (a longer period than subsp. leianthum).

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Conospermum leianthum subsp. leianthum

This subspecies mainly occurs to the north and west of Esperance and prefers the drier and heavier gravelly soils. It has noticeably longer leaves always above 10 cm (those in the photo were 20 cm in length), plus the flower clusters are more widely spaced. Flowering, possibly due to the drier habitat, is generally shorter than the other subspecies, being mainly October and November.

Spider Smokebush - Conospermum teretifolium

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Spider Smokebush - Conospermum teretifolium

A widespread shrub of the Esperance district, although usually represented by individual plants rather than occurring in what you could describe as a colony. Mostly it grows to around a metre in height (little over 3'), but is recorded to 2 metres elsewhere, and in this region it seems to prefer deep sandy soils, being part of the heath community and often associated with Banksia speciosa.

Like many smokebushes this species produces a spectacular floral display with terminal plumes of cream or white flowers that can be seen from a considerable distance. The flowering period has been recorded from August to January, but around Esperance September to December would be the norm and when they can be seen in their prime.

Even when not in flower it has an exotic appearance, with long stout vertical pale yellowish/green foliage and held on sturdy upright stems, to make you momentary wonder what sort of unusual plant you have discovered.

Smokebush - Conospermum distichum

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Smokebush - Conospermum distichum

A compact shrub to a metre (3') in height (although usually smaller) and forming spreading colonies in heathland with deep sandy soil, where the hairy blue and grey flowers provide an eye-catching bright smoky appearance amongst other heath vegetation. As can be seen in the photographs above, this and other Conospermum species have a very small flower opening, so are not designed for bird or mammal pollination, but instead rely on various flying insects to do the job of cross pollination.

The foliage is soft and fine, and the plant blends well into the environment except when in flower when it then excells. Most flowers tend to bloom together making a stiking floral display, which fortunately for wildflower enthusests lasts for several weeks. These features of mass display and long flowering have also made this and other smokebushes, popular with the cut-flower industry, which in some instances have suffered from over-collection, although less so since most cut-flower species these days are grown commercially and not collected from the bush.

In the Esperance region flowering can begin in August and finish during November, although September and October would be the main period when displays are at their best.