Xerochrysum frutescens J.J.Bruhl & I.Telford, 2022

Collins, Timothy L., Schmidt-Lebuhn, Alexander N., Andrew, Rose L., Telford, Ian R. H. & Bruhl, Jeremy J., 2022, There’s gold in them thar hills! Morphology and molecules delimit species in Xerochrysum (Asteraceae; Gnaphalieae) and reveal many new taxa, Australian Systematic Botany 35 (2), pp. 120-185 : 154-155

Xerochrysum frutescens J.J.Bruhl & I.Telford , sp. nov.

Type: AUSTRALIA: Queensland: Moreton: Main Range, Mount Cordeaux , summit ridge, 1 Nov. 2005, I.R. Telford 12874, J.J. Bruhl & L.M. Copeland (holo: BRI!; iso: NE 85983 !, CANB!, K!, NSW!) .

Helichrysum sp. 1 (McPherson Range), J.D. Briggs and J.H. Leigh, Rare or Threatened Austral. Pl. 24 (1988).

Helichrysum sp. (Mt Merino S.T.Blake 21554), A.E. Holland in R.J.F. Henderson (ed.), Queensl. Vasc. Pl.: Names and Distrib. 39 (1994).

Xerochrysum bracteatum subsp. Mount Merino (S.T.Blake 22869) Qld Herbarium, A.E. Holland in P.D. Bostock and A.E. Holland (eds), Census Queensl. Fl. 32 (2007).

Xerochrysum sp. Mount Merino (S.T.Blake 22869) NE Herbarium, CHAH, Austral. Pl. Census (2020) [accessed 20 February 2020].

Xerochrysum ‘Dargan Hill Monarch’, Australian Cultivar Registration Authority 1977.

[ Xerochrysum bracteatum auct . non (Vent.) Tzvelev: N.N. Tzvelev, Novosti Sist. Vyssh. Rast. 27: 151 (1990), p.p., only populations in the Main, McPherson and Tweed Ranges, Queensland and New South Wales].

Diagnosis

Distinguished from X. bracteatum by the perennial life form and shrub-like habit ( v. annual or sometimes short-lived perennial, and erect habit), acuminate to cuspidate phyllary apices ( v. apiculate ), and foliaceous bracts subtending capitula 10–40 mm long (8–10 mm long in X. bracteatum ). Distinguished from X. berarngutta by the taproot ( v. rhizome ), and the hispid leaf lamina adaxial indumentum ( v. hirsute to pilose).

Erect, taprooted, perennial shrub-like herb, up to ~ 80 cm tall. Stems and branches cobwebby, to felted, tomentose, villous, or woolly with septate trichomes, and with glands; internode length 5–40 mm. Basal leaf rosette absent at flowering. Basal leaves oblanceolate to obovate or spathulate; 40–100 mm long and 10–25 mm wide, base amplexicaul and attenuate, margin cobwebby to villous with septate trichomes, apex obtuse and mucronate; abaxial indumentum cobwebby to tomentose or villous with septate trichomes, and with glands; abaxial midvein indumentum cobwebby and villous with septate trichomes, or glabrous; adaxial indumentum cobwebby to hirsute with septate trichomes, and with glands. Cauline leaves oblanceolate to lanceolate, 50–200 mm long and 5–20 mm wide, leaf base amplexicaul and attenuate, margin cobwebby, hispid, or woolly with septate trichomes, apex acute and mucronate; abaxial indumentum cobwebby to villous or tomentose with septate trichomes, and with glands; abaxial midvein indumentum cobwebby, hirsute or woolly with septate trichomes, and with glands; adaxial indumentum cobwebby to hirsute or hispid with septate trichomes, and with glands. Foliaceous bracts subtending capitula 10–40 mm long, margin felted to woolly. Capitula 50–90 mm wide, terminal, in panicles or solitary. Outer phyllaries ovate to broad-ovate, brown, basal margin fimbriate and hispid, abaxial surface smooth, apex cuspidate, or acute to acuminate. Medial phyllaries lanceolate, abaxially yellow, apex acuminate to cuspidate. Stylar appendages deltoid to ovate. Cypsela oblong, ~ 2.5 mm long and 0.9 mm wide, cross-section squarish to circular; pericarp straw- or brass-coloured, idioblasts present. Pappus deciduous, ~ 8 mm long.

Distribution

Restricted to South Eastern Queensland, and New South Wales North Coast bioregions along the Main Range (Great Dividing Range) from Cunninghams Gap, Queensland, south to Acacia Plateau , eastward along the McPherson Range to Springbrook and southward along the Tweed Range, New South Wales ( Fig. 25 ).

Phenology

Recorded flowering November–March ( Fig. 26 ) with mature cypselae collected in May.

152°0 ̍ 0 ̎ E

152°0 ̍ 0 ̎ E

Habitat

Xerochrysum frutescens inhabits rocky slopes and cliff tops at 1000–1150-m altitude in skeletal loamy soils mostly on trachyte and basalt cliff edges of the Main Range and Tweed volcanoes. The species grows in open forest or shrub communities, mostly adjacent to rainforest including Nothofagus moorei closed forest. Associated taxa at Main Range sites include Leptospermum polygalifolium subsp. montanum , Cuttsia viburnea , Pimelea umbratica , Doryanthes palmeri and at McPherson Range sites, Cassinia straminea , Coronidium telfordii , Podolepis monticola , Prostanthera lanceolata and Leucopogon sp. Lamington (G. Leiper AQ633386).

Conservation status

Most populations occur in conservation reserves but there are no precise data on population sizes. Specimen label data indicate fewer than 10 known populations that are localised or restricted in extent, and most occur at altitudes of> 1000 m. Without population data it is not possible to confidently evaluate conservation status. Ongoing threats associated with anthropogenic climate change including heatwaves, extreme drought and intense fires potentially threaten X. frutescens and the associated vegetation. Given the very limited geographic range and estimated small population sizes, we suggest a ‘ Vulnerable ’ status is appropriate under the IUCN (2019) because it fulfils the criteria of D1 and D2. A precise assessment of population size and estimated stability would clarify whether X. frutescens should be listed as ‘ Vulnerable ’, ‘ Endangered ’ or ‘ Critically Endangered ’.

Notes

The two collections from Mount Merino Lookout (I.R. Telford 12886 and I.R. Telford 2632) have relatively long, scattered septate trichomes compared with the shorter, closely spaced septate trichomes seen on specimens from other populations.

Etymology

The specific epithet is from the Latin frutex (a bush or shrub) and refers to the shrub-like habit of this species.

Selected specimens examined

QUEENSLAND: Moreton: Main Range National Park, ~ 200 m S of summit of Mount Cordeaux , 11 Mar. 2005, L.M. Copeland 3904 & A.J. Lynch ( NE!, PERTH) ; Main Range National Park, Goomburra Section , 28 Oct. 2015, P.I. Forster 43151 ( BRI!) ; Mount Mitchell, Cunninghams Gap , 18 Aug. 1992, P.I. Forster 11105 ( BRI!) ; Mount Lindesay , base of trachyte cliffline, 15 Nov. 1990, P.I. Forster 7562 ( BRI!) . NEW SOUTH WALES: North Coast: McPherson Range, Limpinwood Nature Reserve, Mount Merino , 6 Nov. 2005, I.R. Telford 12886 ( NE!) ; Koreelah National Park , 28 Mar. 2009, L.M. Copeland 4353 ( CANB, NE!, NSW) ; Lamington Plateau, Hunter’s Lookout , 12 Mar. 2014, P.I. Forster 40802 ( BRI!) .

Figures

Fig. 25. Distribution of Xerochrysum frutescens.

Fig. 26. Isotype of Xerochrysum frutescens (I.R.Telford 12874, J.J.Bruhl & L.M.Copeland NE 85983).