 Flowers and leaves. Photo © W.R.Barker |
 Fruits, flowers and leaves. Wittunga Botanic Gardens. Photo © I. Holliday |
 Fruits and leaves. Photo © W.R.Barker |
Synonymy
Hakea decurrens R.Br. subsp. physocarpa W.R.Barker, J. Adelaide Bot. Gard. 17: 193 (1996)
T: Black Ra., extreme N end, E side of Picnic Rocks, Grampians, Vic., 23 Apr. 1969, A.C.Beauglehole 30817; holo: AD; iso: MEL.
Hakea longispina Gand., Bull. Soc. Bot. France 66: 229 (1919). T: Victoria, s.d., C.Walter s.n.; holo: LY; probable iso: BR.
Hakea vittata var. glabriflora J.M.Black ex J.H.Willis, Victorian Naturalist 73: 150 (1957), p.p. (excluding French collection, MEL 643057 from Wimmera); Hakea vittata var. glabriflora J.M.Black, Fl. S. Australia 2nd edn, 2: 265 (1948), nom. inval. T: near Stirling East School, S.A., Aug. 1944, J.B.Cleland s.n.; holo: AD; iso: AD, ?MEL, ?NSW.
Hakea sp. aff. acicularis: J.H.Maiden, Proc. Linn. Soc. New South Wales 28: 747 (1904).
[Hakea sericea auct. non Schrad. & J.C.Wendl.: A.J.Ewart, Fl. Victoria 407 (1931), p.p.; W.M.Curtis, Student's Fl. Tasmania 3: 610 (1967); W.R.Barker, J. Adelaide Bot. Gard. 7: 245 (1985), p.p.]
Description
Small tree or shrub, 0.8–5 m tall. Branchlets sparsely to densely appressed-sericeous, quickly glabrescent or persistent to flowering. Leaves widely spreading, grooved below to varying extents, 1.5–8 cm long, 0.7–1.6 mm wide, rapidly glabrescent; apex porrect, with mucro 1–3.5 mm long.
Inflorescence axillary umbel of 1–6 white to pink flowers; rachis simple, 0.5–2.8 mm long, with tomentose or appressed white and/or ferruginous hairs, extending onto pedicels; pedicels 1.2–4.8 mm long. Perianth 4.2–7.2 mm long, glabrous. Pistil 8.5–12.2 mm long.
Fruit 2.1–3.2 cm long, 1.3–2.5 cm wide, finely or coarsely tuberculate, obliquely ovate to broadly ovate; beak small to moderately large, sparsely pustulate or smooth; horns 1–5 mm long; valves with pale wood extending c. 3/4 way to style base, pale wood zone (4.5–) 6–12 mm wide; red-brown wood zone 1–2.5 mm wide. Seed 17–23 mm long, 6.5–10.5 mm wide; wing 3/4 to fully down one side only, dark blackish brown with hyaline network of minute areoles.
Distribution and ecology
Occurs in south-eastern N.S.W., the Grampians, central and eastern Vic., Bass Strait, and possibly northern Tas.
Naturalised in S.A. (Lofty Ra.), Blackheath near Sydney, N.S.W., and probably southern Tas.; also in Portugal.
Found in eucalypt forest, damp heath or dry scrubland in hilly areas in sand, clay, granite, basalt or sandstone, from sea-level to 300 m.
To plot an up to date distribution map based on herbarium collections for this species see Australia's Virtual Herbarium. Localities outside the native range may represent cultivated or naturalised records.
Flowering time
Flowers June–Sept.
Derivation of name
From physa, Greek for a swollen object and carpos, Greek for fruit, a reference to the broader and more woody fruits of this subspecies when compared with ssp. decurrens.
How the infraspecific taxa differ
The subspecies primarily differ in their fruit and branchlet hair characters as shown below. Enright & Goldblum (1999) indicate that ssp. physocarpa (see note below) is not lignotuberous in the Grampians but the species was generally described as lignotuberous by W.R.Barker in the Flora of Australia treatment. Further observations are required across the range of the species to clarify this characteristic in relation to each of the subspecies.
| | Branchlet hairs | Fruit width, cm | Fruit: red-brown layer width, mm | Fruit: pale wood width, mm | Locality/Ecology |
| ssp. decurrens | appressed, soon lost | 1-1.8 | 1-2.5 | 3.5-6 | W slopes and plains of |
| ssp. platytaenia | raised, persistent | 2.6-3.5 | 3-5 | 8-15 | Coastal windswept heaths, NSW, VIC and Bass St islands |
| ssp. physocarpa | appressed, soon lost | 1.3-2.5 | 1-2.5 | (4.5-)6-12 | Non-coastal se NSW, Vic, Bass St; widely naturalised –SA, Tas, NSW, |
Relationships
Part of Section Hakea of Bentham (as Euhakea) and characterised by a non-conical pollen presenter, leaves without obvious venation, perianths with or without hairs and fruits with or without horns. Barker et al. (1999) recognised a number of informal morphological groups within the section.
H. decurrens was treated as part of the Sericea group, a predominantly eastern states group characterised by their simple terete leaves, few-flowered inflorescences, hairy pedicels and solitary, prominently woody fruits, these often markedly verrucose or pusticulate and usually with horns.
Other members of the group are H. actites, H. constablei, H. gibbosa, H. kippistiana, H. leucoptera, H. lissosperma, H. macraeana, H. macrorrhyncha, H. ochroptera, H. sericea and H. tephrosperma, predominantly from the eastern states of Australia.
Notes
Studies in a fire-prone area in the northern Grampians by Enright & Goldblum (1999) compared a lignotuberous or sprouter species (H. rostrata ) and a non-lignotuberous or non-sprouting species (H. decurrens ssp. physocarpa).
For H. decurrens ssp. physocarpa the study found that a population of 17 adults produced 726 potentially viable seeds after a fire; from these seeds 166 seedlings were produced within 6 months of the fire and 96% of these were still alive 5 years later. Seedling recruitment was considerably higher than for the re-sprouting species, H. rostrata . Flowering and fruiting began in the third year and the number of closed fruits on an individual steadily increased with age up to 28 years. None of these fruits opened in the first 12 years but by the time 28 years had been reached up to a quarter of the fruits had opened (such opening is usually associated with death of the branch bearing the fruit). There was no seedling recruitment up to 24 years but after this time seedlings did appear, usually in association with dead adults. Whether the dead adults were as a result of natural senescence, drought or Phytophthora was not clear.
Reference:
The cultivar Hakea Pink Lace, selected and developed by Austraflora represents a selection from the pink-flowered form of this subspecies.
Representative specimens
S.A.: Watiparinga Natl Trust Reserve, Belair, W.R.Barker 1894 (AD). N.S.W.: 16 km N of Timbillica on Princes Hwy, c. 29 km S of Eden, R.Coveny 2930 (NSW). Vic.: 6 km directly ENE of Gembrook, 4 km E along Black Snake Creek Rd from Whites Corner, M.D.Crisp 7127 (CANB, MEL); Grampians, Pomonal Rd, c. 2.5 km from Halls Gap, T.B.Muir 1206 (MEL, UPS). Tas.: Sulphur Ck, Sept. 1915, L.Rodway s.n. (HO).
Weblinks
Link to PlantNET treatment for NSW.
More photographs of this species can be seen on the Australian National Botanic Gardens site.
There are images of H. decurrens in the Key to Tasmanian Plants pages.
Further illustrations
I. Holliday, Hakeas. A Field and Garden Guide 64-65 (2005)