Xerochrysum interiore Paul G.Wilson

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 : 159-161

Xerochrysum interiore Paul G.Wilson , Nuytsia 28: 19 (2017)

Type: 4 miles [~ 6.4 km] east of Acacia Well, Undoolya , Northern Territory, 9 Nov. 1954, G. Chippendale 450 (holo: AD 95805047 ; iso: BRI, CANB 37993 , DNA A0000450, NSW 518728 , PERTH 00423815 *) .

Erect, annual (never biennial), taprooted herb. Stems and branches hispid with septate trichomes, or glabrescent, and with glands; internode length 15–20 mm. Basal leaf rosette often present at flowering, or absent (will flower with loose basal rosette in drier seasons). Basal leaves obovate to spathulate, 70–110 mm long and 15–35 mm wide, base auriculate and attenuate, apex apiculate; abaxial indumentum with glands, midvein indumentum pilose with septate trichomes; adaxial indumentum with scattered septate trichomes. Cauline leaves spathulate to obovate, 50–200 mm long and 10–30 mm wide, leaf base attenuate and auriculate, margin hirsute with septate trichomes, apex mucronate; abaxial indumentum with glands, midvein indumentum hispid with septate trichomes, and with glands; adaxial indumentum hirsute with septate trichomes, and with glands. Foliaceous bracts subtending capitula ~ 2–4 mm long or absent, margin fimbriate or hispid. Capitula 25–40 mm wide, terminal, in panicles. Outer phyllaries broad-ovate, straw-coloured, basal margin fimbriate, abaxial surface smooth, apex obtuse or apiculate. Medial phyllaries ovate to narrow ovate, abaxially yellow, apex cuspidate. Stylar appendages narrowly triangular or rounded. Cypsela ~ 3.5 mm long and 0.9 mm wide, cross-section squarish or circular; pericarp grey–brown, idioblasts present. Pappus deciduous, ~ 10–11 mm long.

Distribution

Occurs sporadically following winter rainfall over a broad area in central Australia, including the Finke, MacDonnell Ranges, Great Sandy Desert, and Central Ranges bioregions, with a disjunct distribution in the Pilbara Bioregion ( Fig. 31 ).

Phenology

Recorded flowering July–September and fruiting September– December.

Habitat

Acacia shrublands on red–orange sandy loam and gravelly loam soils.

Notes

A specimen from Balladonia, Western Australia (B.L.Turner 5251, MEL 602769!) is noteworthy in that it has cobwebby trichomes below the capitulum ( v. short , stiff, septate trichomes) and immediately noticeable, much shorter (15–30 mm long) obovate cauline leaves ( v. spathulate to obovate cauline leaves, 50–200 mm long). The area in which this collection was made is markedly disjunct from all other populations of X. interiore and other species of Xerochrysum in Western Australia

Conservation status

Occurs over a wide geographical area, including in several conservation reserves and is not considered to be rare or threatened. We recommend a status of ‘ Least Concern ’ ( IUCN 2019).

Selected specimens examined

NORTHERN TERRITORY: MacDonnell: 1.4 km N of Erldunda Roadhouse, ~ 50 m E of Stuart Highway , 25 Sep. 2016, J.J. Bruhl 3446 ( NE!, NT!); Alice Springs , 500 m NE of the end of Baldissera Drive , 19 Oct. 2014, T.L. Collins 713 ( NT!, NE!); S of Alice Springs, 17 km along Maryvale Road , 2 Jul. 2014, T.L. Collins 706 ( NT!, NE!). SOUTH AUSTRALIA: unincorporated: De Rose Hill Station ~ 9 km NE of Homestead, 31 Aug. 1989, H.P. Vonow 1288 ( AD!). WESTERN AUSTRALIA: Fortescue: Wanna Munna Road , Pilbara , 22 Aug. 2018, T.L. Collins 1073 & J.J. Bruhl ( CANB!, NE!, NT!, PERTH!). Ngaanyatjarraku: ~ 49 km N of Mount Fanny on Giles–Mount Davies road, 11 May 1977, M. Lazarides 8341 ( CANB, NSW, PERTH!). Dundas : 87.7 km E of Norseman on Eyre Highway, 16 Aug. 1995, R.J. Cranfield 10058 ( PERTH!) .

Figures

Fig. 31. Distribution of Xerochrysum interiore.