Flora of Australia Online
Grevillea hookeriana Meisn., in J.G.C.Lehmann, Pl. Preiss. 1: 546 (1845)
T: Swan R., W.A., [?1844] J.Drummond IV: 633 ; lecto: NY n.v. , fide D.J.McGillivray & R.O.Makinson, Grevillea 420 (1993); isolecto: CGE n.v. , G n.v. , K, LE n.v. , MEL, P n.v.
Shrub 0.5–2.5 m high, to 4 m across. Leaves 1–13.5 cm long, sometimes entire and linear and 0.6–2.6 mm across, and/or variously divided, usually either deeply 2–9-partite or -sect with ascending linear lobes 0.8–1.9 mm across and basal lobes rarely again 2- or 3-partite, or narrowly cuneate and apically digitate, to c. 10 mm wide (at base of lobes) with 3–10 (–23) short ascending apical lobes or teeth; apices ±pungent; margins smoothly revolute; lower surface usually enclosed except for midvein, densely tomentose with flexuose and/or curled hairs in grooves especially near lobe sinuses. Unit conflorescence erect, secund; floral rachis 25–80 mm long. Perianth subsericeous to villous. Pistil 18–21.5 (–23) mm long; ovary ±sessile; style usually glabrous, rarely a few papillae or minute simple erect hairs near middle of ventral side. Follicle 12–18 mm long, tomentose with biramous hairs and sometimes also simple erect glandular hairs.
Occurs in south-western W.A., where widespread throughout much of the wheatbelt in the area bounded by Three Springs, Mt Churchman, Coolgardie and Katanning. Grows in heath or shrubland in sandy soils.
Grevillea hookeriana is a superspecies with several inadequately resolved elements, differing mainly in leaf morphology and to some extent in habit and fruit indumentum; these generally have coherent geographical distributions. Some of these elements have been regarded as separate species in the past but there are several intergrades and the morphological diagnoses usually advanced are not sufficiently consistent to maintain species status at this time. The complex would repay closer research.
The species as a whole has leaves with venation of the upper surface obscure, smoothly rounded margins, and laminas usually entire or with primary division only (rarely the basal lobes again 2- or 3-partite); divided leaves flat to subsecund (lobes not divaricate, and leaf rachis not deflexing at each node); unit conflorescence erect; floral bracts usually acute to apiculate, ovate to narrowly rhomboid, 1.5–3.5 mm long; floral rachis tomentose to shortly villous; nectary prominent, linguiform; pistil 18–21.5 mm long; ovary ±sessile; and styles (usually) maroon to almost black. These character states serve to distinguish it from the most closely related species G. crowleyae and G. calliantha (both of which have pistils ≥ 23 mm long), and G. armigera (which has leaves with secondary division, leaf rachis deflexing at each node, and floral bracts broadly ovate and ≤ 1.5 mm long), as well as more distant relatives such as G. baxteri , G. cagiana , G. coccinea , G. concinna , G. tetragonoloba , G. rigida , G. fastigiata , G. beardiana and G. aneura (all of which are different in some or all of these states).
A Grevillea with pinnatipartite very regular 'herringbone' leaves and red styles, common in horticulture and sold for many years as 'G. hookerana ' [sic] and more recently as G. 'Red Hooks', is a sterile hybrid with a parentage probably involving G. tetragonoloba ; it is illustrated in J.W.Wrigley & M.Fagg, Banksias, Waratahs & Grevilleas 243 (1989), as 'G. hookeriana hybrid'.
Three subspecies are recognised; these intergrade considerably, with morphologically intermediate or ambiguous plants and populations being especially common in the area bounded by Wongan Hills, Merredin and Cunderdin.
Data derived from Flora of Australia Volumes 16 (1995), 17A (2000) and 17B (1999), products of ABRS, ©Commonwealth of Australia