Hart, Taxonomy of Xanthosia huegelii 
443 
Fig. 1. Leaf silhouettes of Xanthosia tasmanica showing variation within and between individuals: 
a, basal; b, mid-branch; c, subtending inflorescence (from Hart 95109); d, basipetal, e, acropetal 
(from Hart 369). All leaves actual size. 
Fig. 2. Leaf silhouettes of Xanthosia huegelii showing variation within and between individuals, 
a, basipetal; b, acropetal (from Hart 95055); c, basipetal; d, acropetal (from Hart 381); 
e, basipetal; f, acropetal (from Hart 95134); g, basipetal; h, acropetal (from Hart 95142). All leaves 
actual size. 
The inflorescences vary in the extent of elaboration (simple or compound) and size 
(rays up to 5 mm long)"in individuals of both leaf forms. Within the group with elliptic 
leaf segments, inflorescences vary from one- to four-rayed with one flower per ray 
(umbellule) and with one flower sometimes present between the rays. The flowers are 
all bisexual and the involucral bracts and bracteoles are all linear. The group with 
linear, oblong, lanceolate or oblanceolate leaf segments also has 1-4 rays in the 
inflorescences with 1 or 2 bisexual flowers in each umbellule, sometimes with one 
flower between the rays. At the north-western extreme of its distribution, in the 
Eneabba area north of Perth, the inflorescences are larger with broader, elliptic 
bracteoles, and up to six bisexual and/or male flowers in each rayed umbellule and up 
to three flowers between the rays. Continuous variation in flower number and 
between elliptic and linear involucral bracts and bracteoles occurs such that division 
of this group is largely arbitrary. The flowers of the two leaf forms are morphologically 
consistent, while the fruit vary in rib number; one form has 5-7 ribs, whereas the other 
has 5-9 ribs. 
