ABCDEFGHIJKLMNOPQRSTUVWXYZ

Habit, leaves and inflorescences. Subspecies indeterminable. Photo I.Holliday

Leaves, inflorescences and fruit. Subspecies indeterminable. Photo I.Holliday

Synonymy

Hakea obliqua R.Br. subsp. parviflora R.M.Barker, J. Adelaide Bot. Gard. 13: 99 (1990)

T: 20 km W of Coorow, Western Australia, 28 Aug. 1973, E.C.Nelson 17237; holo: PERTH; iso: CANB.

Description

Erect dense shrub, 1–2 m tall, ?lignotuberous. Branchlets and young leaves ferruginous. Leaves terete, 1–7 cm long, 1.2–1.5 mm wide, not grooved; mucro erect.

Inflorescence with 2–8 flowers; involucre 2–3 mm long; pedicels 1.5–2.5 mm long, appressed-sericeous, with hairs white, extending onto perianth. Perianth 4.5–5.5 mm long. Pistil 5.5–6.5 mm long; disc of pollen presenter 0.8–1 mm long; gland 0.5–0.7 mm long.

Fruit erect, obliquely broadly ovate or obovate, (1.7–) 2.7–3.5 cm long, 1.3 cm wide, ±smooth apart from sparse corky projections; beak smooth; apiculum straight or curved, 1–6 mm long. Seed 23–28 mm long, occupying part of valve; wing encircling seed body.

Distribution and ecology

Occurs in south-western Western Australia from about Coorow to Fitzgerald River National Park; grows in sand heaths.

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 Aug.–Sept.

Derivation of name

From parvus, Latin for small, and florus, Latin for flower, a reference to the smaller flowers of this subspecies when compared with the typical subsp. obliqua.

top

How the infraspecific taxa differ

As the name suggests, the flowers of ssp. parviflora are smaller than those of ssp. obliqua. This is reflected in all of the floral measurements (see below). The fruits of ssp. obliqua appear to become much more corky with age as well as being mostly longer and wider, but more observations are needed here since there were few mature fruits of ssp. parviflora seen.

There is also a tendency for subsp. parviflora to have longer leaves which are apparently more curved than in ssp. obliqua; this tendency is best shown in the comparative leaf widths which are much less in ssp. parviflora.

Ssp. parviflora occurs in more north-westerly localities than ssp. obliqua, being distributed in the sand heaths from Coorow through to the Fitzgerald NP while ssp. obliqua is found in the sand heaths between the Stirling Ranges and Israelite Bay.

 

ssp. obliqua

ssp. parviflora

Leaf width, mm

1.1-2.5

1.2-1.5

Involucral bud length, mm

3.5-5

2-3

Pedicel length, mm

3.5-6

1.5-2.5

Perianth length, mm

5.5-7.5

4.5-5.5

Pistil length. mm

6.5-10

5.5-6.5

Gland height, mm

1.2-1.5

0.5-0.7

Fruit length, cm

3-4.5

(1.7-)2.7-3.5

Fruit width, cm

2.1-3.5

1.3

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.

Within this section 5 species were assigned to the informal Obliqua group by Barker et al. (1999). The group is close to the Ceratophylla group, sharing the morphological characteristics of few-flowered inflorescences with pubescent flowers on an obscure rachis, oblique pollen presenters and distinctly woody fruits without horns and usually without beaks and seed in which the wing encircles the seed body; the groups differ in the terete leaves of this group compared with the flat leaves of the Ceratophylla group. 

 Members of the group are H. adnata, H. brachyptera, H. obliqua, H. polyanthema and H. psilorrhyncha, all from southern WA.  

Notes

Possibly deserving of species status, but the paucity of collections and lack of knowledge of field characters means that it remains as a subspecies here.

Representative specimens

Western Australia: 5 km S of Namban R., J.S.Beard 7847 (NSW); between Watheroo and Coorow, W.E.Blackall 2583 (PERTH); Dragon Rock Nature Reserve, 75 km E of Kulin, J.M.Brown 088 (PERTH); Wongan Hills, K.F.Kenneally 5822 (PERTH).

Weblinks

Link to FloraBase treatment of this species for WA.

 

A photograph of this species can be seen on the Australian National Botanic Gardens site.

top

Further illustrations

I. Holliday, Hakeas. A Field and Garden Guide 146-7 (2005)

J.A..Young, Hakeas of Western Australia. A Field and Identification Guide 79 (2006)