| Isopogon anethifolius | |
|---|---|
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| Flowers emerging from base of cone | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Proteales |
| Family: | Proteaceae |
| Genus: | Isopogon |
| Species: | I. anethifolius |
| Binomial name | |
| Isopogon anethifolius | |
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| Range in New South Wales (in green) | |
| Synonyms[1] | |
List
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Isopogon anethifolius, commonly known asnarrow-leaf drumsticks[2] ornarrow-leafed drumsticks,[3] is ashrub in the familyProteaceae. The species isfound only in coastal areas nearSydney in New South Wales, and to the immediate west. It occurs naturally inwoodland, open forest andheathland onsandstone soils. An upright shrub, it can reach to 3 m (9.8 ft) in height, withterete leaves that are divided and narrow. The yellow flowers appear in the Spring, from September to December, and are prominently displayed. They are followed by round grey cones, which give the plant its common name ofdrumsticks. The small hairy seeds are found in the old flower parts.
Isopogon anethifolius regenerates afterbushfire by resprouting from its woody base, known as alignotuber, as well as from seed. It wasdescribed byRichard Salisbury in 1796, and was first grown in the United Kingdom the same year. One of the easiest members of the genusIsopogon to grow in cultivation,I. anethifolius grows readily in the garden if located in a sunny or part-shaded spot with sandy soil and good drainage.
Isopogon anethifolius is ashrub usually between 1 and 3 m (3 and 10 ft) high with an uprighthabit (tall and thin with mostly vertical stems).[2] It generally grows taller in more sheltered areas such aswoodlands, and shorter in more exposed areas.[3] The stems are reddish in colour, and new growth in winter is tinged with reddish and tan tones.[4] The leaves areterete (round in cross section) and less than 1 mm (1⁄25 in) in diameter. They branch once or twice in their16 cm (6+1⁄4 in) length. The globular yellow flowerheads, known asinflorescences, appear at the ends of branches in spring and early summer (September to December),[5][6] though occasionally at other times of year.[3] These are up to4 cm (1+1⁄2 in) in diameter.[7] The individual flowers arise out of the central woody globe in a spiral pattern,[3] and are around1.2 cm (1⁄2 in) long.[4] They are straight stalkless structures that originate from a scale on the globe, composed of a tubular structure known as theperianth, which envelopes the flower's sexual organs. The perianth splits into four segments, revealing a thin delicate style tipped with the stigma. At the ends of the four perianth segments are the malepollen-bearing structures known as anthers.[8] Arranged in a spiral pattern, the flowers open from the outer/bottom of the flowerhead inwards.[4] The egg-shaped grey cones are revealed as the old flower parts fall away,[9] and are up to 2.5 cm (0.98 in) in diameter. The seed-bearing nuts are small—up to4 mm (3⁄16 in) across—and lined with hairs.[10] The seed weighs around 4 mg (0.00014 oz).[6]
The terete leaves readily distinguishIsopogon anethifolius from other members of the genus,[4] which have flat leaves and are greater than 1 mm (1⁄25 in) across.[11] On a microscopic level, the supportingground tissue ofI. anethifolius differs from some of its genus by its irregular misshapensclereids (thick-walled cells that make up part of the ground tissue) and contorted cell body.[12]
Isopogon anethifolius was among the plants collected by English botanistJoseph Banks and Swedish naturalistDaniel Solander on 5 May 1770 atBotany Bay during thefirst voyage of Captain James Cook.[13] A drawing by Scottish artistSydney Parkinson was the source for a subsequent painting byJames Britten, published in 1905.[13][14] Solander coined the (unpublished) binomial nameLeucadendron serraria inBanks' Florilegium.[15] English botanistRichard Salisbury described the species in 1796 asProtea anethifolia,[16] from a specimen collected inPort Jackson (Sydney).[17] The species name is derived from theLatin wordsanethum "dill" andfolium "leaf", from the resemblance of its leaves to those ofthe herb.[5] The common name is variously written asnarrowleaf-,[10]narrow-leaf-,[2] ornarrow-leafed drumsticks.[3] The common namedrumsticks is derived from the globular cones of the members of the genus.[18]
In 1799, the Spanish botanistAntonio José Cavanilles describedProtea acufera,[19] later identified as asynonym by Salisbury and Robert Brown.[20][21]I. anethifolius gained its current name in 1809 when it was redescribed as the dill-leaved isopogon (Isopogon anethifolius) by English plantsmanJoseph Knight in his controversial workOn the cultivation of the plants belonging to the natural order of Proteeae.[22][20] Robert Brown had written of the genusIsopogon but Knight had hurried out his work before Brown's. Brown's description appeared in his paperOn the natural order of plants called Proteaceae in theTransactions of the Linnean Society in 1810.[9]
French naturalistMichel Gandoger described fourtaxa in 1919 that he regarded as similar to (but distinct from)I. anethifolius.I. confertus was a plant fromRylstone on theCentral Tablelands, which he distinguished by its crowded leaves that were7–8 cm (2+3⁄4–3+1⁄4 in) long.I. eriophorus was a plant with more scattered leaves that were12–14 cm (4+3⁄4–5+1⁄2 in) long. He describedI. globosus from the Port Jackson district on the basis of round (rather than oval) infructescences (cones), andI. virgatulus fromWestern Australia.[23] All four were subsequently synonymised withI. anethifolius.[22] Gandoger described 212 taxa of Australian plants, almost all of which turned out to be species already described.[24]
The 1891 publicationRevisio generum plantarum was German botanistOtto Kuntze's response to what he perceived as poor method in existing nomenclatural practice.[25] BecauseIsopogon was based onIsopogon anemonifolius,[20] and that species had already been placed by Salisbury in the segregate genusAtylus in 1807,[26] Kuntze revived the latter genus on the grounds ofpriority, and made thenew combinationAtylus anethifolius.[27] However, Kuntze's revisionary program was not accepted by the majority of botanists.[25] Ultimately, the genusIsopogon wasnomenclaturally conserved overAtylus by theInternational Botanical Congress of 1905.[28]
Like all species in the genusIsopogon,I. anethifolius has 13haploid chromosomes.[29]
Isopogon anethifolius is found only in New South Wales, where it occurs in theSydney Basin and surrounds, fromBraidwood northwards to Mount Coricudgy inWollemi National Park.[2] The annual rainfall in these areas ranges from 900 to 1,600 mm (35 to 63 in). The species occurs naturally from sea level to 1,200 m (3,900 ft) altitude and is found onsandstone inheathland and drysclerophyll woodland.[6] Typical trees it is associated with include the scribbly gumsEucalyptus haemastoma andE. sclerophylla and silvertop ash (E. sieberi), open forest plants such as soft geebung (Persoonia mollis), and heathland plants such as heath banksia (Banksia ericifolia), dwarf she-oak (Allocasuarina nana) and Wingello grevillea (Grevillea molyneuxii).[6]
Isopogon anethifolius resprouts from its woody base, known as alignotuber, afterbushfire. It is alsoserotinous—the seeds are held on the plant as acanopy-basedseedbank and are released after fire. These then fall directly to the ground or are blown a short distance by wind.[6] Plants resprouting from the lignotuber can flower in around two and a half years, while seedlings take around three and a half years.[30]
Leaf spotting is caused by the fungusVizella. Flower buds may be damaged byweevils.[6]
Isopogon anethifolius was first cultivated in the United Kingdom in 1796.[7] Along withIsopogon dawsonii, it is the easiest member of the genus to grow.[4] The fine foliage, red stems, bright yellow flowers in spring and distinctive drumsticks afterwards makeI. anethifolius an appealing garden plant. It has potential as a screening plant (its dense foliage can be used for privacy).[31] It prefersacidic soil with extra water, though it does not toleratewaterlogging. A part-shaded position is the preferred location, thoughI. anethifolius grows readily in full sun.[7] Plants can withstand frosts to −8 °C (20 °F).[32] Fertiliser applied in spring assists growth.[31] Young plants can grow long stems that eventually droop, and respond well topruning.[7] The species can be propagated by cuttings or seeds, whichgerminate after 30 to 60 days.[7] Flowering can take several years from seed.[4] Western AustralianIsopogon species includingI. cuneatus andI. latifolius have been grafted onto rootstocks of this species.[32] The flowers, cones and foliage are used in thecut-flower industry.[33]
