Xerochrysum wilsonii T.L.Collins, 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 : 173-175

Xerochrysum wilsonii T.L.Collins , sp. nov.

Type: AUSTRALIA: Western Australia: Darling: Porongurup National Park, upper slopes and summit of Devils Slide , 17 Dec. 2018, T.L. Collins 1160 (holo: PERTH!; iso: CANB!, NSW!, NE 108019 !) .

[ Xerochrysum macranthum auct . non (Benth.) Paul G.Wilson: A.N. Schmidt-Lebuhn et al., Taxon 64(1): 105 (2015), p.p., populations of perennial plants in the Esperance, Jarrah Forest and Warren bioregions with mid-cauline leaves ≥ 12 mm wide only].

Diagnosis

Distinguished from X. macranthum by a perennial life form ( v. annual or biennial), cauline leaves 10–20 mm wide (v. 5–12 mm), capitula 40–60 mm wide (v. 30–50 mm wide).

Erect or occasionally decumbent, taprooted, perennial shrub-like herb, 30–180 cm in length. Stems and branches cobwebby to hispid, scabrid, and with glands; internode length 15–50 mm. Basal leaf rosette absent at flowering. Basal leaves spathulate, 80–160 mm long and 20–30 mm wide, base amplexicaul, margin cobwebby to pilose, and hispid; apex apiculate; abaxial indumentum pilose and with glands, midvein indumentum pilose and with glands; adaxial indumentum hispid, pilose, and with glands. Cauline leaves oblanceolate, 60–110 mm long and 10–20 mm wide, base amplexicaul, margin cobwebby, hispid, and scabrid, apex mucronate; abaxial indumentum with sessile glands and scattered septate trichomes; midvein indumentum hispid, scabrid, and with glands; adaxial indumentum hispid, scabrid, and with glands. Foliaceous bracts subtending capitula ~ 10 mm long, margin cobwebby and hispid. Capitula 40–60 mm wide, terminal, in panicles. Outer phyllaries broad-ovate, pink, white, or straw-coloured; basal margin fimbriate and hispid, abaxial surface smooth, apex apiculate. Medial phyllaries narrow ovate to elliptic, abaxially white, apex cuspidate. Stylar appendages ovate. Cypsela oblong, ~ 2.1 mm long and 0.9 mm wide, cross-section squarish or circular; pericarp brown, idioblasts present. Pappus deciduous, ~ 7–8 mm long.

Distribution

Endemic to the far south-west of Western Australia and recorded in the Esperance, Jarrah Forest and Warren bioregions ( Fig. 43 ).

Phenology

Recorded flowering November–January and fruiting December–February ( Fig. 44 ).

Habitat

Occurring in diverse habitats from montane heath and scree slopes at ~1000-m altitude to coastal heath near sea level, on skeletal sandy soils.

Conservation status

All known populations occur in conservation reserves, but appear to be restricted to specific habitats. We recommend a status of ‘ Data Deficient ’ ( IUCN 2019) and suggest that a detailed analysis of the area of extent be conducted to determine appropriate conservation status.

Notes

At Toolbrunup in Stirling Range National Park, large plants up to 1.8 m in length were seen decumbent across the scree-slope below the summit, with stem diameters up to ~ 100 mm. Occasional plants have been recorded at lower elevations (e.g. J.R. Wheeler 4022 ( PERTH!)), possibly owing to flower picking and subsequent discarding by bushwalkers; however, these lowland populations in Stirling Range National Park do not appear to persist (T. L. Collins, pers. obs., 2018). The informal phrase-names X. sp. Porongurup, X. sp. Limestone and X. sp. Forests have been used at NE for curatorial purposes and this study.

Etymology

The specific epithet honours the work of botanist Paul Graham Wilson (1928–), of the Western Australian Herbarium ( PERTH), who has contributed greatly to Australian daisy taxonomy.

Selected specimens examined

WESTERN AUSTRALIA: Darling : Stirling Range National Park , summit of Bluff Knoll , 16 Dec. 2018, T.L. Collins 1157 ( CANB!, K!, NE!, PERTH!, US!); Stirling Range National Park , summit of Toolbrunup , 16 Dec. 2018, T.L. Collins 1158 ( CANB!, NE!, PERTH!); Walpole– Nornalup National Park , Conspicuous Cliffs , 18 Dec. 2018, T.L. Collins 1161 ( CANB!, K!, NE!, NSW!, PERTH!, US!); Walpole–Nornalup National Park , Delta Road , 18 Dec. 2018, T.L. Collins 1162 ( CANB!, NE!, PERTH!); Collier Peak , Porongurup Range , 20 Nov. 1987, G.J. Keighery 8722 ( PERTH!); Yallerungup Peak , Porongurup Range, 15 Dec. 1986, G.J. Keighery 8419 ( PERTH!); Mount Many Peaks , 4 Oct. 1994, S. Barrett 24 ( PERTH!) .

Figures

Fig. 43. Distribution of Xerochrysum wilsonii.

Fig. 44. Isotype of Xerochrysum wilsonii (T.L.Collins 1160, NE 108019).