Hart, Taxonomy of Xanthosia huegelii 
447 
Xanthosia pusilla Bunge in Lehm., PI. Preiss. 1: 291 (1845). 
Type: In arenosis humidis umbrosisque ad fluvium King's-River, Plantagenet, Western 
Australia, 14 Oct 1840, Herb. Preiss. No. 2078 (holo P; iso MEL!). 
Xanthosia villosa Turcz., Bull. Soc. Imp. Nat. Moscou 22(2): 32 (1849). 
Type: Western Australia: Swan River, /. Drummond IV. n. 139 (lecto, here chosen, KW, 
photo!; isolecto BM!, K!). Turczaninov's type designation is discussed under 
Taxonomic History. 
Erect or ascending perennial herb, 5-20 cm high. Plant near glabrous to densely 
villous, the stem excorticating when aged. Leaves cauline, trifoliolate. Petiole 
sheathing shortly at the base to entirely sheathing, 1-7 mm long. Leaflets linear, 
oblong, lanceolate or oblanceolate, the segments equal, very rarely lobed, 4-38 mm 
long, 1-10 mm wide; margins entire; apex acute. Inflorescence a compound umbel with 
1-4 rays, sometimes contracted and appearing simple, 1-6 flowers per ray and up to 3 
flowers between the rays; the flowers all bisexual to bisexual and male. Rays terete, to 
5 mm long. Involucral bracts 1-4, elliptic or linear, foliaceous, green, longer than the 
rays, 3-9 mm long, 1-4 mm wide; apex acute or obtuse. Bracteoles 2 or 3, elliptic or 
linear, foliaceous, green, shorter to longer than the flowers, 4-6 mm long, 1-3 mm 
wide; apex acute or obtuse. Inflorescences sessile or pedunculate; peduncles to 25 mm 
long. Flowers pedicellate. Sepals ovate, 1.1-2.9 mm long, 0.7-1.4 mm wide, green; base 
truncate; apex acute, glabrous. Petals equal to sepals, 1-1.2 mm long, 0.3-0.6 mm wide, 
white; midrib adaxially keeled and bridged; apex acute or obtuse; appendage smooth. 
Stamens approximately equal to the perianth. Nectaries raised and prominent, 0.4-0.7 mm 
high, cream, hirsute. Styles 0.7-1.9 mm long. Ovary hirsute. Male flowers different 
from bisexual ones in having undeveloped inconspicuous ovary, with styles barely 
protruding above nectaries. Fruit brown, ovoid, 2.3—2.8 mm long, 1.9—2.3 mm wide, 
0.4-0.7 mm deep. Monocarps villous on the summit, rarely glabrous, oblong in 
transverse section, 5-9 ribbed; the ribs keeled. Chromosome number >7=10 and n=20 
(Keighery 1982; Table 1). (Fig. 4). 
Flowering: most of the year. 
Notes: Xanthosia huegelii is a variable species particularly in indumentum and 
inflorescence size. A variant with dense greyish indumentum, broader bracteoles and 
a greater number of flowers per umbellule occurs in Western Australia around 
Eneabba and south to Perth, with intergrading forms south of Perth. Placement of 
specimens into any form-groups is largely arbitrary. 
Distribution: coast and adjacent ranges in Western Australia (between Eneabba and 
Esperance), South Australia (on the Eyre Peninsula, Kangaroo Island and east from the 
Lofty Ranges) and south-western Victoria (the Grampians to Wilsons Promontory) 
(Fig. 5). 
Ecology: widespread in forest and heath usually on sandy soils. 
Selected Specimens (over 200 examined): Western Australia: 6 miles [c. 10 km] N of junction of 
Eneabba South road with Coorow-Green Head road. Chapman s.n., 30 Aug 1977 (PERTH 3260611); 
0.5 km N of Marchagee Track W of Brand Highway, Cranfield 8892 & Kabay, 3 Sept 1993 (PERTH); 
14.6 km along the Mooliabeenee road from the Great Northern Highway towards Gingin, Hart 
95055, 25 Oct 1995 (PERTH, SYD); Delta road, Walpole-Nornalup National Park, Hart 95108, 8 Nov 
1995 (PERTH, SYD); Porongorups, 1.3 km along Angwin Park road from Bolganup road. Hart 
95129, 13 Nov 1995 (PERTH, SYD); 2.8 km along the South Coast Highway from Chester Pass road 
towards Jerramungup, Hart 95134, 15 Nov 1995 (SYD); Lucky Bay, Cape Le Grand National Park, 
Hart 95142, 18 Nov 1995 (SYD); Eneabba, Humphreys 342, 21 Sept 1966 (PERTH); Keighery 5366, 
Oct 1975 (PERTH); Gold Holes, Chester Pass, Stirling Ranges, Keighery 5533, 19 Oct 1982 (PERTH); 
Goode Beach area, Torndirrup National Park, 18 km S of Albany, Keighery 8513, 
5 Nov 1986 (PERTH); Cape Le Grand National Park E of Esperance, Royce 8713, 21 Oct 1969 
