Two-leaved hakea | |
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Hakea trifurcata growing near Perth | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Proteales |
Family: | Proteaceae |
Genus: | Hakea |
Species: | H. trifurcata |
Binomial name | |
Hakea trifurcata | |
Hakea trifurcata, commonly known as two-leaf, [2] two-leaved hakea, [3] or kerosene bush, [4] is a shrub, endemic to the south-west of Western Australia. The species has two leaf forms, needle-like or oblong egg-shaped. Unlike most hakea species the fruit remain green at maturity and resemble the broader leaf form. The mimicry creates a camouflage, reducing predation of the seed by granivores in particular cockatoos.
Hakea trifurcata is an open or dense shrub 0.4–3 m (1 ft 4 in – 9 ft 10 in) high and about 3.5 m (11 ft) wide. It does not form a lignotuber. The branchlets have white or rusty coloured flattened, short soft silky hairs or are densely covered in soft hairs and quickly become smooth. The shrub has two forms of leaves usually needle-like, curved, straight or may be divided in segments, 2.2–7.5 cm (0.87–2.95 in) long and 0.8–1.3 mm (0.031–0.051 in) wide, grooved below and ending in a sharp point. The second form is wider, oblong to egg-shaped 2–5 cm (0.79–1.97 in) long, 6–19 mm (0.24–0.75 in) wide with a central vein and is either wedge-shaped at the apex or narrows gradually. Both leaf shapes have flattened, dense, silky rusty or white hairs but quickly become smooth. The inflorescence consists of between one and ten sweetly, strongly scented cream, white or pink flowers often with red styles. The clusters of flowers appear in leaf axils, producing nectar attractive to bees and birds. However the flower scent is conversely described by editors in Flora of Australia as "a strong smell, sometimes described as fetid". [5] The flowers are surrounded by overlapping bracts 4.5–5.5 mm (0.18–0.22 in) long. The pedicels are 3–4 mm (0.12–0.16 in) long and covered with cream or rusty coloured hairs that are either short, soft and thickly matted or with flattened silky hairs, both forms extending onto the 6.5–10 mm (0.26–0.39 in) long perianth. The green fruit are smooth, obliquely egg-shaped and appear to resemble flat leaves, 1.5–2.5 cm (0.6–1 in) long and 0.5–0.8 mm (0.020–0.031 in) wide. The fruit of this Hakea species are not beaked or woody. Flowering occurs between April and October. [2] [3] [6] [7] [8]
Hakea trifurcata was first formally described by Robert Brown in 1810 and published the description in Transactions of the Linnean Society of London . [9] [10] Hakea trifurcata is named from the Latin (tres), referring to the three forked leaves. [3]
Two-leaf hakea is a widespread species growing from north of Geraldton to east of Esperance. Two-leaved hakea grows in a variety of soils including sand or laterite in mallee or low heathland. [3] [6] [7]
Hakea trifurcata has two distinct leaf forms, either needle-shaped or a broader oblong leaf visually similar to the fruit. The broader leaves only form when the shrub reaches sexual maturity and produces fruit. Unlike that of most other hakeas the fruit of Hakea trifurcata remain green at maturity and resemble the broader leaves of the species in shape and colour. Trials were conducted at the Perth Zoo to determine whether the broad leaves deterred granivores from foraging the fruit by the short-billed black cockatoo ( Calyptorhynchus funereus latirostris ) . A paper by Groom, Lamont and Duff suggested the leaves adjacent to the fruit, create camouflage protecting and shielding the fruit from predation. The broader leaf tends to double over shielding the fruit, the mimicry making it difficult to distinguish by the white-tailed cockatoo the most frequent predator of hakea fruit. The broader leaves increase in size the further away from the fruit, again possibly diverting the cockatoos from consuming the follicles. It is believed these adaptations evolved as a mechanism to reduce the destruction of seeds by granivores. It was noted by botanist and ornithologist Richard Schodde "that the short-billed black cockatoo and the yellow-tailed black cockatoo ( Calyptorhynchus funereus ) actively predate Hakea species, perching in the bushes to open up 'green' follicles with their bills". [5] This species grows in fire-prone locations and does not resprout after fire, therefore continued populations require a "seed bank" to maintain numbers. [11] [12]
Hakea trifurcata is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife. [2]
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Hakea sericea, commonly known as bushy needlewood or silky hakea, is a large shrub with a profusion of mainly white flowers from July for several months. It is endemic to eastern Australia. It has become an environmental weed in some countries.
Hakea decurrens, commonly known as bushy needlewood, is a species of shrub or small tree in the family Proteaceae.
Hakea rugosa, commonly known as wrinkled hakea or dwarf hakea, is a shrub of the family Proteaceae native to Australia. It has sharp needle-shaped leaves and white or cream fragrant flowers in profusion from August to October.
Hakea lorea, commonly known as bootlace oak or cork tree, is a species of shrub or small tree in the family Proteaceae found in central and northern Australia. It has needle-shape leaves, yellow, white or green flowers and hard corky bark.
Hakea tephrosperma commonly known as hooked needlewood, is a shrub or small tree species in the family Proteaceae. It has cream flowers, needle-shaped leaves and is one of the taller species adaptable for dry to temperate locations.
Hakea eriantha, commonly known as tree hakea, is a shrub or small tree endemic to the east coast of Australia. It has white flowers on a woolly stem in leaf axils, long narrow leaves with reddish new growth. Found growing at higher altitudes in moist or sclerophyll Eucalyptus woodland.
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Hakea brownii commonly known fan-leaf hakea is a shrub in the family Proteaceae native to an area in the Wheatbelt region of Western Australia. This species shares a common name with Hakea baxteri due to its distinctive leaves.
Hakea candolleana is a shrub in the family Proteaceae native to areas along the west coast in the Wheatbelt and Mid West regions of Western Australia. A cream-white winter flowering species, useful as a garden ground cover.
Hakea circumalata is a shrub in the family Proteaceae native to an area in the Wheatbelt and Mid West regions of Western Australia. A small shrub producing a profusion of strongly scented pink to red flowers in dense clusters from July to September.
Hakea carinata is a shrub in the family Proteaceae native to an area in South Australia. A frost hardy small to medium species adaptable to a range of free draining situations. Its prickly habit creates a good wildlife habitat.
Hakea kippistiana is a shrub in the family Proteaceae and endemic to Western Australia. It is a dense prickly shrub with sharp needle-shaped leaves with fragrant white, cream or pink flowers from November to February.
Hakea varia, commonly known as the variable-leaved hakea, is a shrub of the family Proteaceae and is endemic to Wheatbelt, South West, Great Southern and Goldfields-Esperance regions of Western Australia. It is a dense prickly shrub with creamy-white or yellow flowers and variably shaped leaves.
Hakea tuberculata is a flowering plant in the family Proteaceae and is endemic to several isolated areas along the coast in the Peel, South West, Great Southern and Goldfields-Esperance regions of Western Australia. It is an upright shrub with white flowers and rigid, prickly leaves.
Hakea obliqua, commonly known as needles and corks, is a shrub in the family Proteaceae and is endemic to an area in the Wheatbelt, Great Southern and Goldfields-Esperance regions of Western Australia.
Hakea polyanthema is a species of flowering plant in the family Proteaceae that is endemic to Western Australia. It is a shrub with needle-shaped leaves and small groups of small unpleasantly scented flowers in leaf axils.
Hakea psilorrhyncha is a flowering plant in the family Proteaceae, it is endemic to a small area on the west coast in the Wheatbelt and Mid West regions of Western Australia. It has needle-shaped, sharply pointed leaves and clusters of scented brownish yellow flowers.
Hakea rigida is a flowering plant in the family Proteaceae with a restricted distribution and endemic to the western Goldfields region of Western Australia. It is a dense shrub with grey bark and sprays of pink flowers in spring.
Hakea strumosa is a shrub in the family Proteaceae endemic to an area in the Wheatbelt, Great Southern and the Goldfields-Esperance regions of Western Australia. A dense, very prickly shrub with a profusion of small, deep pink or red flowers in spring.