Xerochrysum gudang T.L.Collins & J.J.Bruhl, 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 : 155-157

Xerochrysum gudang T.L.Collins & J.J.Bruhl , sp. nov.

Type: AUSTRALIA: Queensland: Cook: Somerset Lookout, Fly Point , ~ 350 m SW of lookout parking area, 50 m from rocky coast, 28 June 2018, T.L. Collins 1061 & J.J. Bruhl, (holo: BRI!; iso: CANB!, CNS!, NE 107429 !) .

[ Xerochrysum bracteatum auct. non (Vent.) Tzvelev: N.N. Tzvelev, Novosti Sist. Vyssh. Rast. 27: 151 (1990), p.p., populations in the Torres Strait and on the northern tip of Cape York Peninsula, Queensland only].

Diagnosis

Distinguished from X. bracteatum by a perennial life form ( v. annual or sometimes short-lived perennial), the presence of septate trichomes on leaf lamina abaxial surface ( v. with glands), and the absence of glands on stems and leaf lamina adaxial surface ( v. with glands). Distinguished from X. strictum , X. banksii and X. boreale by the absence of glands on stems and leaf adaxial surfaces (present on X. strictum , X. banksii and X. boreale ).

Decumbent to erect, taprooted, perennial herb. Stems and branches up to 70 cm long, cobwebby, hirsute, scabrid, or woolly, to glabrescent; internode length 10–20 mm. Previous season’s flowering stems marcescent. Basal leaf rosette absent at flowering. Basal leaves oblanceolate to spathulate, 70–120 mm long and 5–15 mm wide, base subamplexicaul, margin villous with septate trichomes, apex mucronate; abaxial indumentum villous with septate trichomes, and with glands, midvein indumentum pilose with septate trichomes; adaxial indumentum villous with septate trichomes. Cauline leaves oblanceolate to lanceolate, 50–100 mm long and 6–15 mm wide, base auriculate and amplexicaul, margin cobwebby and hirsute with septate trichomes, apex mucronate; abaxial indumentum hispid with septate trichomes and with glands, midvein indumentum cobwebby and hispid with septate trichomes; adaxial indumentum cobwebby and hirsute with septate trichomes. Foliaceous bracts subtending capitula 6–8 mm long, margin woolly to cobwebby, and hispid. Capitula 30–40 mm wide, terminal, in panicles. Outer phyllaries ovate to broad-ovate, brown or straw-coloured, basal margin fimbriate and hispid, abaxial surface smooth, apex apiculate. Medial phyllaries narrow ovate to lanceolate, abaxially yellow, apex cuspidate. Stylar appendages deltoid. Cypsela oblong, ~ 2.7 mm long and 0.75 mm wide, cross-section circular; pericarp straw- or brass-coloured, idioblasts present. Pappus deciduous, ~ 8–9 mm long.

Distribution

Known only from the Somerset area of northern Cape York and nearby islands in the Cape York Peninsula Bioregion ( Fig. 27 ). Extensive survey of similar habitat on Cape York Peninsula has not recorded populations of Xerochrysum between Jardine River National Park and Cooktown, except for X. strictum near Coen (J. R. Clarkson, pers. comm., 2018).

Phenology

Recorded in flower June–October and fruiting in June ( Fig. 28 ).

Habitat

Windswept grassy herbfields among shrubland on low rocky headlands.

Conservation status

Population-size data are scant, with 50–100 plants being estimated at Somerset Lookout in 2018, and other specimen label data describing populations as ‘sporadic’ (L.J. Brass 18778), and ‘infrequent’ (K.R. Thiele 905). 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. gudang should be listed as ‘ Endangered ’ or ‘ Critically Endangered ’.

Notes

The decumbent habit observed in the field was retained on glasshouse-grown plants. The informal phrase name X. sp. Fly Point NE Herbarium has been used at NE for curatorial purposes and this study.

Etymology

The species epithet is the traditional name of the type locality, a place important to traditional owners (Christo Lifu, pers. comm., 2020), as a noun in apposition (Shenzhen Code art. 23.5; Turland et al. 2018).

Selected specimens examined

QUEENSLAND: Cook: Albany Island , s.dat., W. Hill 71 ( K000899118 *); Fly Point, near Albany Pass , Cape York Peninsula , 25 June 1973, S. Powell 9 ( CANB!) ; Fly Point , ~ 11 km SE of Cape York , 30 Oct. 1965, L.S. Smith 12636 ( BRI!) ; Newcastle Bay , Cape York Peninsula , 15 Feb. 1986, D.L. Jones s.n. ( BRI!) ; Newcastle Bay , 2.5 miles S of Somerset, 2 May 1948, L.J. Brass 18778 ( A, CANB!) ; Headland above Nanthau Beach , 4.5 km direct line SSW of Somerset, 30 June 1985, K.R. Thiele 905 ( CANB!) .

Figures

Fig. 27. Distribution of Xerochrysum gudang.

Fig. 28. Isotype of Xerochrysum gudang (T.L.Collins 1061 & J.J.Bruhl, NE 107429).