Hakea invaginata B.L.Burtt, Hooker's Icon. Pl. ser. 5, 5: t. 3428 (1943)
Hakea sulcata var. intermedia Ewart & Jean White, Proc. Roy. Soc. Victoria 23: 293 (1911). T: Cowcowing, W.A., 1904, M.Koch 1056; holo: MEL; iso: AD, HO, K, NSW, PERTH.
Hakea invaginata var. pachycarpa B.L.Burtt, Hooker's Icon. Pl. ser. 5, 5: t. 3428 (1943). T: cultivated at Blackwood, S.A., from seed from Pithara, W.A., Oct. 1932, E.Ashby 95; holo: K.
Erect shrub, 1.3–4 m tall, non-sprouting. Branchlets densely tomentose and appressed-pubescent at flowering. Leaves terete, with 5 deep narrow grooves running entire length, 7–22 cm long, 1.2–1.5 mm diam., glabrous to sparsely sericeous on faces, moderately sericeous in grooves; longitudinal veins 5 (= the broad faces separated by grooves).
Inflorescence a solitary axillary umbelliform raceme, grouped to form elongate brushes, with 60–80 flowers per axil; pedicels glabrous. Perianth usually pink, sometimes white ageing deep pink. Pistil 10–12.5 mm long; gland sub-globular.
Fruit 1–6 per axil, stalked, obliquely elliptic-acuminate, sometimes curved, 1.6–2.2 cm long, 0.8–1.1 cm wide, scarcely beaked but often abruptly narrowed into a short apiculum. Seed obliquely ovate-elliptic, acute, 11–14 mm long, 5–6 mm wide; wing extending fully down both sides of body, more broadly down one side than other, usually notched near base adaxially, sepia to dark brown with blackish brown patches towards base.
Distribution and ecology
Occurs in inland south-western W.A. from between Kellerberrin and Southern Cross along the Great Eastern Hwy, north to Yuna and Mt Magnet; grows in Acacia- or Melaleuca-dominated shrubland on sand plain.
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.
Derivation of name
From invaginatus, Latin for enclose or to fold in so that an outer becomes an inner surface, a reference to the longitudinally grooved leaves of this species.
Part of the Conogynoides group recognised by Bentham and characterised by a conical pollen presenter, veined leaves, glabrous perianth and fruits without horns. Barker et al. (1999) recognised a number of informal morphological groups within the section.
One of these was the Ulicina group. This group of 21 Hakea species was combined morphologically because they all have simple flat leaves or leaves which are apparently terete but when looked at in cross section are clearly angled; these angled leaves are longitudinally furrowed and often referred to as sulcate. Furthermore the group has inflorescences with 6-80 small flowers (with 3-18 mm long pistils) and erect woody fruits.
Members of the group are H. aenigma, H. carinata, H. costata, H. cygna, H. dohertyi, H. erecta, H. gilbertii, H. invaginata, H. lehmanniana, H. marginata, H. meisneriana, H. mitchellii, H. myrtoides, H. pycnoneura, H. repullulans, H. rigida, H. scoparia, H. stenocarpa, H. sulcata, H. subsulcata and H. ulicina, mostly from southern WA but also from south-eastern Australia.
While there is some variation in the fruit as seen in median view (some are abruptly narrowed into the apiculum while others are more gradually narrowed), there is a more or less continuous gradation. Variation in fruit size is not correlated. Recognition of a distinct var. pachycarpa is, therefore, not warranted.
This species is sometimes confused with H. scoparia, H. meisneriana or H. subsulcata. Hakea invaginata is distinct from all of them because the apparent striations on the leaves are in fact extremely narrow deep grooves much narrower than the flattened ridges. In H. meisneriana and H. subsulcata , the striations are the veins which protrude at the angles. In H. scoparia, the leaves are deeply but openly and broadly grooved, the grooves as wide as the ridges. The differences are readily apparent in cross-sections of the leaves.
Hakea invaginata has been grown in cultivation, sometimes as 'H. sulcata', and the forms with especially bright pink flowers make excellent garden subjects where well-drained soils are available.
W.A.: Bunjil area, July 1971, C.Chapman s.n. (MEL, NSW, PERTH); 70 km W of Yalgoo, H.Demarz 6851 (CANB, PERTH); 80 km NW of Bullfinch, P.G.Wilson 6194 (AD, PERTH).
Link to FloraBase treatment of this species for WA.
More photographs of this species can be seen on the Australian National Botanic Gardens site.
B.L.Burtt, loc. cit.;
W.R.Elliot & D.L.Jones, Encycl. Austral. Pl. 5: 211 (1990);
J.Young, Hakeas of W. Australia, Botanical District of Avon 16, 54 (1997)
I. Holliday, Hakeas. A Field and Garden Guide 98-9 (2005)
J.A..Young, Hakeas of Western Australia. A Field and Identification Guide 54 (2006)