| Horny cone-bush | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Proteales |
| Family: | Proteaceae |
| Genus: | Isopogon |
| Species: | I. ceratophyllus |
| Binomial name | |
| Isopogon ceratophyllus | |
 | |
| Occurrence data fromAustralasian Virtual Herbarium | |
| Synonyms | |
Isopogon ceratophyllus, commonly known as thehorny cone-bush orwild Irishman, is a plant of the familyProteaceae that is endemic to the coast inVictoria,South Australia and on theFurneaux Group of islands inTasmania. It is a small woody shrub that grows to 100 cm high with prickly foliage. It is extremely sensitive to dieback from the pathogenPhytophthora cinnamomi
Isopogon ceratophyllus is a prickly shrub, growing to 15–100 cm (6–40 in) tall and to 120 cm (4 ft) across. The oval to round flower heads, known as inflorescences, appear between July and January, and are around 3 cm in diameter.[3]
Isopogon ceratophyllus was first described byRobert Brown in his 1810 workProdromus Florae Novae Hollandiae et Insulae Van Diemen.[2][4] The specific epithet is derived from theAncient Greek wordscerat- "horn" andphyllon "leaf", relating to the leaves' resemblance to antlers.[5] In 1891, German botanistOtto Kuntze publishedRevisio generum plantarum, his response to what he perceived as a lack of method in existing nomenclatural practice.[6] BecauseIsopogon was based onIsopogon anemonifolius,[7] and that species had already been placed byRichard Salisbury in the segregate genusAtylus in 1807,[8] Kuntze revived the latter genus on the grounds of priority, and made the new combinationAtylus ceratophyllus for this species.[9] However, Kuntze's revisionary program was not accepted by the majority of botanists.[6] Ultimately, the genusIsopogon wasnomenclaturally conserved overAtylus by theInternational Botanical Congress of 1905.[10]
Common names includehorny cone bush and, from Kangaroo Island,wild Irishman.[5]
The species ranges from south-western Victoria into the south-eastern corner of South Australia[3] and in theFurneaux Group of Bass Strait islands, principallyFlinders,Cape Barren andClarke Islands. A King Island record has not been reconfirmed and is unlikely.[11] It is the onlyIsopogon species found in South Australia.[5] It grows on sandy soils in open eucalyptus forest or woodland. or heathland.[3]
Isopogon ceratophyllus is listed as endangered on theIUCN Red List based on a February 2019 assessment.[1]
Isopogon ceratophyllus is extremely sensitive to dieback (infection by the pathogenPhytophthora cinnamomi). Fieldwork in the Brisbane Ranges in 1994 showed thatI. ceratophyllus, which had been common in areas before dieback and had vanished along with other sensitive species, had yet to return after 30 years. This was despite other sensitive species, such as grasstree (Xanthorrhoea australis), smooth parrot-pea (Dillwynia glaberrima), erect guinea flower (Hibbertia stricta) and prickly broom heath (Monotoca scoparia), eventually regenerating around 10 years post-infection.[12] All Tasmanian populations are at risk of eradication byP. cinnamomi. Plants are perishing at Wingaroo Nature Reserve on Flinders Island from exposure to the pathogen.[13]
Rarely cultivated, it is slow growing and requires well-drained yet moist sandy soils.[14] It would suit arockery garden.[5]
