Grevillea juniperina | |
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Scientific classification
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Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Proteales |
Family: | Proteaceae |
Genus: | Grevillea |
Species: | G. juniperina
|
Binomial name | |
Grevillea juniperina |
Grevillea juniperina, commonly known as juniper- or juniper-leaf grevillea or prickly spider-flower, is a plant of the family Proteaceae native to eastern New South Wales and southeastern Queensland in Australia. Scottish botanist Robert Brown described the species in 1810, and seven subspecies are recognised. One subspecies, G. j. juniperina, is restricted to Western Sydney and environs and is threatened by loss of habitat and housing development.
A small, prickly-leaved shrub between 0.2–3 m (0.66–9.84 ft) high, G. juniperina generally grows on clay-based or alluvial soils in eucalypt woodland. The flower heads, known as inflorescences, appear from winter to early summer and are red, orange or yellow. Birds visit and pollinate the flowers. Grevillea juniperina plants are killed by bushfire, regenerating afterwards from seed. Grevillea juniperina adapts readily to cultivation and has been important in horticulture as it is the parent of many popular garden hybrids.
Grevillea juniperina has a spreading or erect habit (growth form) and it grows to between 0.2–3 m (0.66–9.84 ft) in height. The branchlets are thick and sturdy. The prickly leaves are generally stiff and are 0.5–3.5 cm (1⁄4–1+3⁄8 in) long and 0.5–6 mm (1⁄32–1⁄4 in) wide. They are crowded along the stems. Flowering occurs throughout the year, peaking between midwinter and early summer, though it varies between the different subspecies. Subspecies allojohnsonii flowers from September to February, [3] subspecies trinervis flowers from August to December, [4] and subspecies juniperina, amphitricha, sulphurea, villosa and fortis flower in August and September. [5] [6] [7] [8] [9] The spider-flower arrangement of the inflorescence has several individual flowers emerging from a central rounded flower head—reminiscent of the legs of a spider. [10] The flowers are red, pink, orange, yellow or greenish, and are mostly terminal—arising on the ends of stems—though they occasionally arise from axillary buds. They are 2.5–3.5 cm (1–1+3⁄8 in) long. [11] [12] The perianth is finely furred on the outside, while the pistil is smooth; it is 1.5–2.7 cm (5⁄8–1+1⁄8 in) long. Flowering is followed by the development of seed pods, each capsule is 10–18 mm (3⁄8–3⁄4 in) long, and releases one or two seeds when ripe. [13] The narrow oval seed is 7.5–12 mm (1⁄4–1⁄2 in) and 2.2–3.3 mm (1⁄16–1⁄8 in) wide, with a swelling at the apex and a short wing. Both surfaces are covered with tiny hairs. [14]
Similar species include the Wingello grevillea ( Grevillea molyneuxii), which can be distinguished by its prominent midvein on the leaf undersurface, and the red spider-flower ( G. speciosa), which has wider leaves with lateral veins and longer pistil. [14]
The type specimen for this species was collected from the Port Jackson area (Sydney district) and was described by botanist Robert Brown in 1810, who gave it the specific epithet juniperina that alludes to its juniper-like foliage. [14] Likewise, it is commonly known as juniper- or juniper-leaf grevillea, as well as prickly spider-flower. [15] The lectotype was selected by Don MacGillivray in 1993 from a collection by George Caley in 1803 11 km (6.8 mi) northwest of Prospect in what is now Sydney's outer western suburbs. Brown placed it in the series Lissostylis in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen. [16]
English botanist and explorer Allan Cunningham collected what he called Grevillea sulphurea in 1822 near Coxs River in the Bathurst area, where it grew alongside G. rosmarinifolia and G. arenaria subspecies canescens. [17] This was later synonymised with G. juniperina, [17] before being recognised as a distinct subspecies.
George Bentham placed G. juniperina in Section Lissostylis in his 1870 Flora Australiensis. This section has become the Linearifolia group of 45 species of shrub in southeastern Australia. [18] Within this group, G. juniperina is classified in the Speciosa subgroup, five species of bird-pollinated grevilleas found in eastern Australia. The others are G. molyneuxii, G. dimorpha, G. oleoides and G. speciosa. [19]
In 2000, Robert Owen Makinson described seven subspecies of G. juniperina in the Flora of Australia, and the names are accepted by the Australian Plant Census:
Subspecies sulphurea hybridises with G. juniperina subsp. trinervis in the southern and western Blue Mountains. [13]
Killed by bushfire, Grevillea juniperina regenerates afterwards by seeds that germinate after lying dormant in the soil, [13] stimulated by exposure to heat and smoke. Plants over 1 m (3.3 ft) high produce more seed. Intervals of 10 to 15 years between fires are thought to be most beneficial for the species' survival, as this allows seed numbers to build up in the soil over time. [34] Grevillea juniperina can also colonise disturbed areas, though overgrowth of Bursaria spinosa can negatively impact its spread. [34]
Grevillea juniperina is pollinated by birds, [13] with bees also recorded visiting flowers. [34] The leaves are food for caterpillars of the cyprotus blue butterfly ( Candalides cyprotus). [35] A springtail species of Australian origin—Calvatomina superba—was found on Grevillea juniperina cultivated at the Lost Gardens of Heligan in Cornwall. [36]
Subspecies juniperina is listed as a vulnerable species on Schedule 2 of the Threatened Species Conservation Act 1995 in New South Wales. [5] Its habitat is threatened by housing development, [15] road upgrading, inappropriate fire regimes, weed invasion, rubbish dumping and trampling either by people or cars. [37]
Allan Cunningham sent seed of G. juniperina to England in 1820; it was grown there the following year. Baron Charles von Hügel grew the species in Vienna in 1831. It has been grown outdoors in southern England, particularly G. juniperina subspecies sulphurea. [14] Grevillea juniperina adapts easily to cultivation and grows in a wide range of soils and aspects in locations with good drainage. [38] Long-flowering, it attracts birds such as honeyeaters with its nectar. The prickly dense foliage is also a good nesting site and shelter, [39] particularly for smaller birds, such as finches. [40] Many forms and hybrids have been commercially propagated and sold, some having more horticultural appeal than others. Low winter temperatures promote more prolific flowering and pruning promotes dense foliage. [14] Plants are readily propagated by cuttings or seed, [41] although propagation by cuttings is required to ensure the new plants have the same characteristics of the parent. [39] Direct contact with the plant may cause a skin rash. [42]
Many cultivars have been selected for horticultural use, either selected forms or hybrids with other Grevillea species. One prominent early breeder was Leo Hodge of W Tree, Victoria. Hodge became interested in breeding grevilleas after finding seedlings in his garden. His first trials involved crossing G. juniperina with G. victoriae, producing G. 'Poorinda Queen', which was the first to flower, followed by G. 'Poorinda Constance', G. 'Poorinda Leane' and G. 'Poorinda Pink Coral' respectively, all in 1952. [43]
Cultivars include:
Grevillea juniperina | |
---|---|
| |
Scientific classification
![]() | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Proteales |
Family: | Proteaceae |
Genus: | Grevillea |
Species: | G. juniperina
|
Binomial name | |
Grevillea juniperina |
Grevillea juniperina, commonly known as juniper- or juniper-leaf grevillea or prickly spider-flower, is a plant of the family Proteaceae native to eastern New South Wales and southeastern Queensland in Australia. Scottish botanist Robert Brown described the species in 1810, and seven subspecies are recognised. One subspecies, G. j. juniperina, is restricted to Western Sydney and environs and is threatened by loss of habitat and housing development.
A small, prickly-leaved shrub between 0.2–3 m (0.66–9.84 ft) high, G. juniperina generally grows on clay-based or alluvial soils in eucalypt woodland. The flower heads, known as inflorescences, appear from winter to early summer and are red, orange or yellow. Birds visit and pollinate the flowers. Grevillea juniperina plants are killed by bushfire, regenerating afterwards from seed. Grevillea juniperina adapts readily to cultivation and has been important in horticulture as it is the parent of many popular garden hybrids.
Grevillea juniperina has a spreading or erect habit (growth form) and it grows to between 0.2–3 m (0.66–9.84 ft) in height. The branchlets are thick and sturdy. The prickly leaves are generally stiff and are 0.5–3.5 cm (1⁄4–1+3⁄8 in) long and 0.5–6 mm (1⁄32–1⁄4 in) wide. They are crowded along the stems. Flowering occurs throughout the year, peaking between midwinter and early summer, though it varies between the different subspecies. Subspecies allojohnsonii flowers from September to February, [3] subspecies trinervis flowers from August to December, [4] and subspecies juniperina, amphitricha, sulphurea, villosa and fortis flower in August and September. [5] [6] [7] [8] [9] The spider-flower arrangement of the inflorescence has several individual flowers emerging from a central rounded flower head—reminiscent of the legs of a spider. [10] The flowers are red, pink, orange, yellow or greenish, and are mostly terminal—arising on the ends of stems—though they occasionally arise from axillary buds. They are 2.5–3.5 cm (1–1+3⁄8 in) long. [11] [12] The perianth is finely furred on the outside, while the pistil is smooth; it is 1.5–2.7 cm (5⁄8–1+1⁄8 in) long. Flowering is followed by the development of seed pods, each capsule is 10–18 mm (3⁄8–3⁄4 in) long, and releases one or two seeds when ripe. [13] The narrow oval seed is 7.5–12 mm (1⁄4–1⁄2 in) and 2.2–3.3 mm (1⁄16–1⁄8 in) wide, with a swelling at the apex and a short wing. Both surfaces are covered with tiny hairs. [14]
Similar species include the Wingello grevillea ( Grevillea molyneuxii), which can be distinguished by its prominent midvein on the leaf undersurface, and the red spider-flower ( G. speciosa), which has wider leaves with lateral veins and longer pistil. [14]
The type specimen for this species was collected from the Port Jackson area (Sydney district) and was described by botanist Robert Brown in 1810, who gave it the specific epithet juniperina that alludes to its juniper-like foliage. [14] Likewise, it is commonly known as juniper- or juniper-leaf grevillea, as well as prickly spider-flower. [15] The lectotype was selected by Don MacGillivray in 1993 from a collection by George Caley in 1803 11 km (6.8 mi) northwest of Prospect in what is now Sydney's outer western suburbs. Brown placed it in the series Lissostylis in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen. [16]
English botanist and explorer Allan Cunningham collected what he called Grevillea sulphurea in 1822 near Coxs River in the Bathurst area, where it grew alongside G. rosmarinifolia and G. arenaria subspecies canescens. [17] This was later synonymised with G. juniperina, [17] before being recognised as a distinct subspecies.
George Bentham placed G. juniperina in Section Lissostylis in his 1870 Flora Australiensis. This section has become the Linearifolia group of 45 species of shrub in southeastern Australia. [18] Within this group, G. juniperina is classified in the Speciosa subgroup, five species of bird-pollinated grevilleas found in eastern Australia. The others are G. molyneuxii, G. dimorpha, G. oleoides and G. speciosa. [19]
In 2000, Robert Owen Makinson described seven subspecies of G. juniperina in the Flora of Australia, and the names are accepted by the Australian Plant Census:
Subspecies sulphurea hybridises with G. juniperina subsp. trinervis in the southern and western Blue Mountains. [13]
Killed by bushfire, Grevillea juniperina regenerates afterwards by seeds that germinate after lying dormant in the soil, [13] stimulated by exposure to heat and smoke. Plants over 1 m (3.3 ft) high produce more seed. Intervals of 10 to 15 years between fires are thought to be most beneficial for the species' survival, as this allows seed numbers to build up in the soil over time. [34] Grevillea juniperina can also colonise disturbed areas, though overgrowth of Bursaria spinosa can negatively impact its spread. [34]
Grevillea juniperina is pollinated by birds, [13] with bees also recorded visiting flowers. [34] The leaves are food for caterpillars of the cyprotus blue butterfly ( Candalides cyprotus). [35] A springtail species of Australian origin—Calvatomina superba—was found on Grevillea juniperina cultivated at the Lost Gardens of Heligan in Cornwall. [36]
Subspecies juniperina is listed as a vulnerable species on Schedule 2 of the Threatened Species Conservation Act 1995 in New South Wales. [5] Its habitat is threatened by housing development, [15] road upgrading, inappropriate fire regimes, weed invasion, rubbish dumping and trampling either by people or cars. [37]
Allan Cunningham sent seed of G. juniperina to England in 1820; it was grown there the following year. Baron Charles von Hügel grew the species in Vienna in 1831. It has been grown outdoors in southern England, particularly G. juniperina subspecies sulphurea. [14] Grevillea juniperina adapts easily to cultivation and grows in a wide range of soils and aspects in locations with good drainage. [38] Long-flowering, it attracts birds such as honeyeaters with its nectar. The prickly dense foliage is also a good nesting site and shelter, [39] particularly for smaller birds, such as finches. [40] Many forms and hybrids have been commercially propagated and sold, some having more horticultural appeal than others. Low winter temperatures promote more prolific flowering and pruning promotes dense foliage. [14] Plants are readily propagated by cuttings or seed, [41] although propagation by cuttings is required to ensure the new plants have the same characteristics of the parent. [39] Direct contact with the plant may cause a skin rash. [42]
Many cultivars have been selected for horticultural use, either selected forms or hybrids with other Grevillea species. One prominent early breeder was Leo Hodge of W Tree, Victoria. Hodge became interested in breeding grevilleas after finding seedlings in his garden. His first trials involved crossing G. juniperina with G. victoriae, producing G. 'Poorinda Queen', which was the first to flower, followed by G. 'Poorinda Constance', G. 'Poorinda Leane' and G. 'Poorinda Pink Coral' respectively, all in 1952. [43]
Cultivars include: