Pimelea angustifolia - Narrow-leaved Pimelea

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Pimelea angustifolia - Narrow-leaved Pimelea

Pimelea angustifolia is a WA endemic, but is one of the most widely distributed Pimelea species in Western Australia. It is found from Kalbarri (500 km or 310 miles north of Perth) around the coast to the SA boarder, plus as far inland as Menzies (120 km or 75 miles north of Kalgoorlie). With such an extensive distribution that includes several climate zones, it is therefore not surprising P. angustifolia is a highly variable species.

Just on flower colour alone, P. angustifolia can be pink (around Albany), or yellow elsewhere, but is more commonly white or cream, which is the case around Esperance. It also has a wide tolerance of habitat that range from gravel, to clay or a limestone substrate, generally with a sandy covering, it will also tolerate conditions varying from seasonally wet to very dry. So Pimelea angustifolia is a highly variable and adaptive plant.

As the species name suggests, the leaves are usually narrowly elliptic to linear and up to 3 cm (11/4”) in length, but maybe flat or concave, with acute or obtuse tips. There are mostly 4 involucral bracts (base of flower), but apparently in the NW portion of its range, there can be 6. However, what is reasonably consistent are the hairs on the bi-sexual flowers, with those below the circumscission point (weak ring, usually just above the ovary, where the upper flower, when dead, brakes away) are longer, more dense and coarser than the fine hairs above. The discarded upper portion of the floral tube is hairless on the inside. As you might be gathering with Pimelea plants, the size and type of hair, growing on what portion of the plant, are important identification features.

Pimelea angustifolia, tends to be a colonising plant, with strong germination after bushfires or soil disturbance, but is slowly pushed out when the growth of taller and more vigorous vegetation overtakes them. The flowering time as with most Pimelea species is quite lengthy, with fresh flowers being produced continually, which with this species and depending on local weather conditions, can be anytime from July to February.

Pimelea is part of the Thymelaeaceae family, which are commonly known as Riceflowers.

Reference:

A Revision of the Western Australian Thymelaeaceae

By BL Rye

Nuytsia Vol 6. No 2. 1988.

Pimelea sulphurea - Yellow Banjine

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Pimelea sulphurea - Yellow Banjine

This shrub species only just gets into the Esperance region, with the above probably the most easterly colony, being on the edge of a gravel quarry off Fields Road about 110 km (70 miles) NW of Esperance, where common but very localised. Here the habitat is a shallow sandy soil overlying gravel; it is an exposed location and would be very dry through the warmer months, which might explain the stunted and sparsely branched nature of this colony. Even the leaf and flower size is at the lower end of its taxonomic range, which I might add, varies considerably.

The normal distribution of Pimelea sulphurea is further west than the above, spreading to Albany, then NW to south of Geraldton, finally turning SE to the Southern Cross region, so occupies a range of climate zones. This distribution means a large variation in annual rainfall (30-80 cm or 12”-31.5”), which influences the size and appearance of the species, with leaf length ranging from 2-16 mm (less than 1/8” to 5/8”) and the flower length 6.5-17 mm long (1/4” to over 5/8”). However the yellow flowers of the local form are very intense, as commonly elsewhere it is often a cream color. The flowering period also varies being dependent on rainfall, but is usually between July and November.

Pimelea sulphurea tends to be very open and even spindly wherever it occurs, but locally with its smaller components, appears even more so. It grows to around 0.7 of a metre (28”), although plants in the above colony were less than ½ metre (20”) in height. In order to separate this highly variable species from others, the leaves and stem are without hairs. The flowers are pendant and hairy outside but glabrous (without hairs) inside. Importantly, it has 3 or more pairs of involucral bracts (leaf-like under flower clusters), which are largely glabrous on the outside, but mostly hairy inside, plus the innermost have ciliate (fine hairs) on the margins.

In Western Australia there are around 70 Pimelea species and subspecies, with over 100 Australia wide. They are also known as Rice-flowers or Banjines, with many ornamental species grown for the home garden. They belong to the Thymelaeaceae Family that is represented worldwide (especially Africa) and includes species like Daphne, Dais, Dirca (leatherwood) and others.

Pimelea aeruginosa – Thymelaeaceae

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Pimelea aeruginosa – Thymelaeaceae

There are many ornamental Pimeleas that are also known as Rice Flowers, and of which Pimelea aeruginosa is one of them with its neat blue/green foliage and large pendant yellow flower clusters. Recorded growing to 11/2 metres (5’) in height, locally it is more common about half that size and can be found after bushfires or soil disturbance NW of Esperance, usually on gravel soils.

Pimelea aeruginosa is mostly an inland species, occurring from west of Kalgoorlie to the Geraldton region, then SE to Esperance. The individual hairless flowers are slender tubular and individually are not particularly ornamental, but are clustered within 2-3 cm (1”) diameter yellow bracts, which go on to develop an orange blush as the internal flowers progress to seed.

This species is not found east of Esperance, although a similar looking species Pimelea pendens that has sparkling white flowers does. The flowering of P. aeruginosa is recorded from May to October, but locally July would be the more usual starting period.

Pimelea drummondii – Thymelaeaceae

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Pimelea drummondii – Thymelaeaceae

Plants from the Pimelea genus are commonly known as Rice Flowers and are especially widespread and diverse in Western Australia. A number are quite spectacular and grown commercially like the Qualup Bell and the Pink Rice Flower, the first having large colourful bracts that largely cover the weeping flower clusters, whist the latter has colourful flowers that are erect and the bracts largely hidden.

Pimelea drummondii falls into the weeping, large bract type, which vary from cream/green to reddish. It grows to 2 metres (over 6’) in height and can form compact colonies, favouring sandy hollows and moist fine sand/laterite soils. Possibly because of its higher moisture requirement it is mainly restricted to coastal and near coastal environments, whereas the similar looking Pimelea cracens favours drier conditions further inland, although it is also found in coastal districts.

Distinguishing features of Pimelea drummondii when compared to Pimelea cracens, is the bracts that hold the flower clusters do so quite tightly and their tips are strongly recurved, giving a hat or helmet appearance. The flowers are either cream or white and have long hairs from the ovary to the sepals (in this instance the petal-like lobes), but equally distinctive are the sessile (stalkless) leaves, whereas the Pimelea cracens leaves have a small but distinctive pedicel (stalk).

Growing from Israelite Bay (east of Esperance) to Bremer Bay (west of Esperance) with odd collections around Albany it is recorded flowering from May to November, but without adverse weather conditions July to October would be more usual.

Pimelea cracens - Thymelaeaceae

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Pimelea cracens - Thymelaeaceae

In the southern portion of Western Australia, the genus Pimelea is the only representative of the Thymelaeaceae family, but nevertheless it contains a very diverse group of attractive plants. Thecanthes the other genus in WA, is Pimelea like, but only found in the far north of the State. All species have small tubular flowers, which on their own are not overly spectacular, but are mostly clustered into heads of many flowers to make them more pleasing to the eye.

Some species like Pimelea ferruginea produce terminal clusters of bright pink flowers to create an eye-catching display, whilst others like Pimelea cracens, although with less spectacular flowers, are covered by large coloured bracts and dangle like Christmas decorations to produce a different, but equally interesting display.

Pimelea cracens is often around a metre (4’) in height, but can grow taller and did have two subspecies, but these are now obsolete and no longer apply. Pimelea cracens is a common species around Esperance, particularly to the north in the mallee district near saltlakes, where it favours a heavy loam over limestone. They are often encountered in scattered small congregations along roadsides, but can form considerable sized colonies two or so years after a bushfire, when previous larger smothering vegetation has not yet regrown.

There are a couple of similar looking species in the district that are easily confused with this one. However, when examining mature floral arrangements, the more obvious things to note regarding this species are the green/cream hairless bracts, which only loosely cover the flower clusters, plus are not strongly recurved near the tips. All three species have long silky hairs on the outside of individual flowers, plus similar looking foliage and growth habit, which taxonomically place them together.

This species is recorded flowering from July to December, but this is highly dependent on seasonal rainfall, which a little inland to the North and NE of Esperance, where Pimelea cracens is commonly found can be unreliable. However it is nearly always in bloom from August to October.

Update 3/10/10

An interesting feature of this Pimelea is the change of color of the outer bracts, once the small tubular flowers shrivel and fall, leaving only covered maturing seed. I had encountered the red coloured bracts before, but owing to the similarity of several species in the district, was not sure to whom they belonged. However from a very large colony of many hundreds, their floral bracts were progressively changing from a cream/green to a deep red, which had begun in September and should continue through October or even longer.

Pink Rice Flower - Pimelea ferruginea

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Pink Rice Flower - Pimelea ferruginea

In the Esperance region, the Pink Rice Flower is a very common shrub growing to around a metre (3') in height, but is usually much less and mostly restricted to coastal calcareous sands, particularly on stabilised tertiary dunes. In WA it is also very widespread ranging from the Nullarbor to near Geraldton, a distance of around 1600 km (1000 miles). Pimelea ferruginea is recognised by many home gardeners not only due to its prolific and long-flowering habit, but because it is one of the most popular Australian garden plants, and as testament to this popularity, the Pink Rice Flower can even be seen in gardens where the home owners would not knowingly plant an indigenous species that might conflict with their roses and rhododendrons.

In an open situation, the Pink Rice Flower is fast growing and develops a compact dome shape thanks to radiating soft flexible branches that are attractively clothed in neat bright green oval/elliptical leaves, arranged in two opposite rows (decussate), and atop is a head of bright long flowering pink flowers. Therefore with such virtues, it is not surprising Pimelea ferruginea has been so commercially successful.

Flowers vary from pale to deep pink and some commercial forms are quite reddish. I have also encountered the odd white flowering form too, but these are rare. Flowering occurs from August to February and as these plants can be locally dominant (particularly after bushfire) many grand displays are available for the rambling wildflower enthusiast.

Pimelea brachyphylla - Thymelaeaceae

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Pimelea brachyphylla - Thymelaeaceae

There are numerous Pimelea species in WA, which vary from the small and insignificant to the large and spectacular and can be found in many domestic gardens in company of other indigenous flora. Most species have not been given a common name, but the group as a whole are generally referred to as Rice Flowers. They do not have petals, but petal-like sepals that surmount a long floral tube.

Pimelea brachyphylla is a common and widespread species around Esperance, particularly in disturbed areas or where it has recently been burnt, but generally is found in habitats associated with heathland vegetation. It can grow to a metre (3') in height, but is more often around half that size. If not restricted by other vegetation it forms a compact rounded shrub and will reveal its neat opposite (decussate) foliage. Some varieties (like the one above) are bright pink in bud, but open to a sparkling white four petal-like flower to form attractive multi-flowered heads. These heads are subtended by green bracts, which have red margins and being a diagnostic feature, can be used as an identification aid.

Flowering is anytime from June to October and if you are fortunate you may see the butterflies who do most of the Pimelea genus pollination, although moths and other insects with a proboscis long enough to reach the end of the floral tube would also contribute.