Darwinia oxylepis

Gillham's bell
D. oxylepis in Cranbrook wildflower garden, Cranbrook, Western Australia.
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Myrtales
Family:	Myrtaceae
Genus:	Darwinia
Species:	D. oxylepis
Binomial name
Darwinia oxylepis (Turcz.) N.G.Marchant & Keighery[1]

Darwinia oxylepis, commonly known as Gillham's bell, is a plant in the myrtle family Myrtaceae. It grows as an dense, upright shrub 1.0 - 1.5 metres (3 – 4.5 ft) high and produces large numbers of red inflorescences prominently displayed on the ends of the branchlets in spring. It is one of a group of Darwinias including D. leiostyla, D. macrostegia, D. meeboldii, D. collina and D. squarrosa collectively known as mountain bells. The species is found in only a few seasonally moist gullies near the lower slopes of the Stirling Range National Park and nearby Porongurup National Park and is therefore classified as endangered.^[2]

Description

Gillham's bell is a small, dense, upright shrub to about 1.5 metres high, with erect branches and short branchlets. Its leaves are about 10 mm long by about 1 mm wide and are almost cylindrical or triangular in cross section. Bell-shaped, flower-like inflorescences appear from August to November. These are clusters of about 10 drooping, nectar-rich flowers surrounded by bright red petal-like bracts up to 30 mm long.^[3]

Taxonomy and naming

Darwinia oxylepis is one of about 70 species of Darwinia endemic to Australia, the majority being endemic to southern Western Australia. This species was originally described by Nikolai Turczaninow in 1852. He gave it the name Genetyllis lejostyla, but it was transferred to Darwinia leiostyla (Turcz.) Domin by Karel Domin in 1923. The Australian botanists N. G. Marchant and Greg Keighery recognised D. lejostyla and D. oxylepis as separate species, so that it is now known as Darwinia oxylepis (Turcz.) N.G.Marchant & Keighery.^[4]

The specific epithet (oxylepis) is derived from the Greek words oxy = sharp and lepis = flake or scale, referring to the shape of the bracts enclosing the flowers.^[3]

Distribution and habitat

This darwinia grows in stony, peaty sand in rocky gullies that are wet in winter.^[5]There are only four known populations of D. oxylepis, all of them in national parks (Stirling Range and Porongurup). They grow in areas known to be significantly affected by Phytophthora cinnamomi fungus to which they are vulnerable. They are also in areas that are prone to bushfire. The species is killed by fire and regenerates from seed stored in the soil but it takes up to four years before new plants produce seed. More frequent fire events may therefore cause loss of populations. The plants also grow in areas frequented by tourists and are at risk from trampling and unauthorised picking of plant parts.^[2]

Conservation status

Darwinia oxylepis is classified as "rare flora" by the Western Australia government.^[6] It meets the criteria for classification as Endangered (EN) under criteria B1+2c on the Red List of the World Conservation Union (IUCN, 1994) due to its being known from fewer than five locations and due to a continuing decline in habitat quality and area although it is not listed at present.

In October 2000, a total of about 4,000 plants were counted in all four areas, but after a bushfire later that month, there were none.^[2]

The species is also listed as Endangered by the Australian Government Environment Protection and Biodiversity Conservation Act (1999).^[7]

Cultivation

As with others in the genus, D. oxylepis is not well known in cultivation. It is difficult to grow from seed but relatively easy to grow from cuttings although generally short-lived in the garden. It has been grafted onto the hardier eastern Australian D. citriodora and this is the preferred method of propagation.^[3]

References