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multicellular, biseriatc, simple eglandular hairs and duplex hairs scattered adaxially; lobes c. 1.0 
mm long, acute; anthers 2.0-2.5 mm long, basally acuminate and shorter than Lhe filament collar, 
with narrowly triangular, sterile, terminal appendage; filament collar 0.4-0.6 mm long; stylar arms 
oblong, 2.6-3.0 mm long, with narrowly half-conic, sterile terminal appendages bearing long, 
botuliform collecting hairs above the sligmatic lines. Achene obovoid, c. 2. 5-2.8 x c. 0.8 mm, 
sericeous with duplex and glandular hairs; venation indistinct; carpopodium central. Pappus 
biseriate, with c. 75 free, minutely barbellate bristles equal to or subequal to the tubular florets. 
Flowering period. September. 
Distribution. Endemic to Dirk Hartog Island in the Carnarvon District, Eremaean Botanical 
Province, Western Australia, occurring between 25-26° S and 1 12-1 13° E (Figure 8). 
Habitat. In shallow sand above limestone amongst tall open heath (shrub steppe) on coastal 
cliff-top. 
Conservation status. This species is known only from its type locality. The ’kwongan’ vegetation 
in which it occurs extends over several 100 hectares. There arc no stock in the vicinity. Extensive 
searching on the adjacent mainland by me in 1986 failed to locate populations there. 
The presence of O. occidenlissima on Dirk Hartog Island reinforces recent proposals to declare 
the island as a National Park (Anonymous 1987). In particular, any proposal to modify vegetation 
at the northern end of the island should be rejected unless further, viable populations of 
O. occidentissima are located in areas free from interference. 
O. occidentissima is clearly a vulnerable species, not presently endangered but possibly at risk 
over a longer period. It thus appears to warrant the category IV in the coding system of Leigh et al. 
(1981). 
Other specimens examined. WESTERN AUSTRALIA: Dirk Hartog Island Lprecise locality 
withheld], B.R. Muslin 4304 (PERTH). 
Etymology. The specific epithet draws attention to the fact that this species of Olearia is that with 
the most westerly distribution in Australia. 
Notes. The dense, intricate, multicellular, uniscriatc eglandular hairs found on the vegetative parts 
of plants of this species place it in Olearia section Eriotriche. 
In the handbook of Grieve & Blackall (1975) specimens of this species will key to 
O . pimeleoides (DC.) Benth., to which it is probably closely related. O. occidentissima can be 
distinguished from the latter by its habit, which is prostrate rather than erect; by its florets, which 
bear duplex hairs abaxially; and by its pappus, which comprises c. 75 rather than 39-65 bristles. 
The duplex hairs observed on the abaxial surfaces of both ray and disc florets are identical to 
those found on achenes of this and most other species of Olearia. They have not been recorded on 
the florets of any other species in this genus. 
It is no small measure of the need for continuing taxonomic research on the Australian flora that 
this distinctive species remained apparently uncollected until 1972 and hitherto undcscribcd in the 
vicinity of the first recorded landing on Australian shores by a European, namely the Dutchman 
Dirk Hartog in 1616 (Burbidgc & George 1978), and of the first authenticated botanical collections 
by Europeans in Australia, namely those made in 1699 by William Dampicr (George 1971). 
