110 
PLANTS INDIGENOUS TO 
[. Rutacece. 
(in B. megastigma) purplisli-black outside and yellow inside, spreading, rarely subcampanulate- 
connivent. Filaments often hairy and at the apex glandulous-tumescent. Fertile anthers generally 
subcordate and terminated by a white appendage; the barren ones, when formed, often far the 
largest. Carpels generally very blunt. Placental membrane attached by the very short fumcle to 
the seed, ovate or lanceolate, acuminate, white, seldom purplish. Seeds black. Raphe sometimes 
tumid towards the base.—Zieria, Smith, in Transact. Li/run. Soc. iv. 216 ; Cyanathamnus, Lindl. 
Swan Riv. Bot. 18. 
The species of Boronia are much more copious in South-Western and South-Eastern Australia 
than in the intervening parts of the country, being comparatively rare in the territory of South Australia; 
they are also more copious in the litoral districts than far inland; many prefer stony mountainous 
tracts; some ascend to alpine regions. The number of species has been generally over-estimated. 
None extend from the east coast to the western shores; none with barren anthers are yet found 
beyond Western Australia; whilst Zieria, which differs principally in the number of stamens, and 
may be retained as a genus, if this note is deemed sufficiently important for distinction, is foreign to 
the western part of the continent. The number of floral parts is singularly invariable, unless in 
monstrose flowers. Only in B. elatior occur, according to Bartling (Plant. Preiss. i. 170), barren 
petaline stamens. B. grandisepala (Fragm. Phyt. Austr. i. 66), of which B. artemisifolia constitutes 
the pinnate-leaved form, is singular for the size of its sepals, which considerably excel that of the 
corolla. The carpological characters of all these plants are congruous. The prseflorescence of the 
corolla is unusually variable, not only in the genus but even in some of the species ; thus B. megastigma 
shows, as in many other species, two outer and two inner petals, but the same species produces also 
flowers with regular imbricative aestivation. The species with alternately fertile and sterile stamens 
may be separated sectionally under the appellation Dimorphanthera. R. Sweet describes (in Dons 
Gen. Syst. i. 794) a Zieria octandra, which, it is presumed, combines the disk of Zieria with the number 
of stamens of Boronia. Only one Boronia of the subgenus Zieria produces constantly simple leaves, 
B. veronicea, F. M., of Kangaroo Island and Encounter Bay, this being moreover the only species of 
the section Zieria which occurs in South Australia. 
Boronia is in its affinity nearest approaching to Eriostemon, whilst through B. arborescens it is 
not less in habit than in most other characters connected with Euodia, which scarcely differs from it 
in any other points than in the large ovate or suborbicular cotyledons and the short radicle. Thereby 
a close contact again is established with Acronychia, which genus completes the link between Rutacece 
and Aurantiaceae. Discussing the affinities of these genera, it may be appropriate to observe, that 
Euodia ternata (Melicope ternata, Forst. Gen. 28) differs as a genus solely in octandrous flowers from 
Euodia, according to an analytical comparison of the former, confirming the perfect exactness of the 
figure furnished in Hooker’s leones Plantarum, t. 603, with Euodia micrococca of Eastern Australia. 
The integument of the seeds is bony in both with a friable outer layer, the radicle superior and about 
half as long as the broad-ovate foliaceous cotyledons, which are placed across the copious albumen. 
Thus Melicope holds the same position to Euodia as Boronia to Zieria. Singular appears the frequent 
development of a fifth and occasionally even a sixth carpel both in Euodia ternata and E. micrococca, 
an irregularity not obvious in Boronia, but parallel to that in Acradenia, a Tasmanian genus, as far as 
can be judged without knowledge of its embryonic characters very allied to Euodia, from which only 
the permanently adnate endocarp seems to distinguish it. The three hitherto known Australian 
species of Euodia have a considerable range over the eastern coast-tracts, and are well marked, 
besides by many other characters in their seeds. Those of E. micrococca are brownish-black; those 
