Flora of Australia Online
Isopogon trilobus R.Br., Trans. Linn. Soc. London 10: 72 (1855)
Atylus trilobus (R.Br.) Kuntze, Revis. Gen. Pl. 2: 577 (1891). T: (near base of mountain in granite hills) [Lucky Bay?, W.A.], R.Brown (Britten 3251) ; lecto: BM; isolecto: BM, fide D.B.Foreman, Fl. Australia 16: 481 (1995).
Isopogon tripartitus R.Br., Suppl. Prodr. Fl. Nov. Holl. 8 (1830). T: ora occid.-merid., King George's Sound [W.A.], 1828–1829, W.Baxter ; lecto: BM; isolecto: BM, fide D.B.Foreman, Fl. Australia 16: 481 (1995).
Isopogon tripartitus var. plurilobus Domin, Vĕstn. Král. Ceské Společn. Nauk, Tř. Mat. Přír. 1921–22(2): 5 (1923). T: sandy plain, Cranbrook to Warrungup, W.A., A.A.Dorrien-Smith s.n. ; n.v.
Isopogon trilobus var. eloba F.Muell., Fragm. 6: 239 (1868). T: Cape Riche, W.A., G.Maxwell ; syn: MEL.
[Petrophile trifida auct. non R.Br., nom. inval. , nom. illeg. : C.Loddiges, Bot. Cab. 19, t. 1883 (1833)]
Illustration: W.E.Blackall & B.J.Grieve, How to Know W. Austral. Wildfl. part 1, 2nd edn, 150 (1988).
Shrub to c. 2 m tall. Branchlets pale to reddish brown, slightly pubescent, glabrescent. Leaves varying from 3–9-toothed to deeply 3–5-lobed; petiole to c. 2–5.5 cm long; lamina narrowly cuneate, flat, to c. 2–5.5 cm long, thick, obscurely veined; lobes usually with a sharp or callous point. Inflorescence ovoid to globose, often barrel-shaped, terminal, sessile, solitary, to c. 25–30 mm diam.; involucral bracts few, broadly ovate, imbricate, acute to acuminate, tomentose; cone scales closely imbricate, cuneate, acuminate, becoming truncate, densely woolly. Flowers c. 8–10 mm long, cream to yellow, silky-pubescent. Pollen presenter c. 5 mm long, fusiform, minutely and sparsely hairy along fine ridges. Cones barrel-shaped, c. 28 mm diam. Nuts ovoid, beaked, c. 4 mm long, villous. Fig. 101J–K.
Widespread near the south-west coast from near the Stirling Range to Israelite Bay, W.A. Occurs in heath or shrubland in sand or sand overlying laterite. Flowers Sept.–Dec. Map 193.
W.A.: Lucky Bay, A.S.George 7516 (PERTH); Cape Le Grand Natl Park, R.D.Royce 8618 (PERTH); 7 km S of Stirling Range Natl Park on Chillinup Rd, D.B.Foreman 1452 (CANB, MEL, PERTH); 22.5 km E of Mt Ragged road junction with road to Israelite Bay, Cape Arid Natl Park, D.B.Foreman 1311 (CANB, MEL, PERTH).
A somewhat variable species with regard to leaf morphology. Extremely narrow-lobed forms were previously placed in I. tripartitus . These may be found growing with broader lobed forms and a range of intermediate types has been observed by the author in a single population.
Data derived from Flora of Australia Volumes 16 (1995), 17A (2000) and 17B (1999), products of ABRS, ©Commonwealth of Australia