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as they grow up, are collected into a compact cone. Myrica, on the contrary, 
has distinct drupes, each somewhat immersed in a somewhat fleshy involucre 
(or calyx), which, although at first hypogynous, is eventually, after fecunda- 
tion, extended beyond the ovary, with which it is conglutinated. Of such an 
involucre there is no trace in Casuarina, since the lateral scales, surrounding 
each achenium like a 2-valved capsule, by no means answer to the calycine 
involucre of Myricacese, but rather to those interior bractlets which we observe 
at the base of the drupes in M)rricaceae. FI. Jav. 
Geography. New Holland, Malayan and South Sea plants. 
Property. Timber excellent. 
GENUS. 
Casuarina, L. 
Alliance V. DATISCALES. 
Essential Character. — Carpels seyeral. -Seetfc numerous. Leases alternate. 
By no means a natural assemblage. It is probable that both the orders 
comprehended for the moment under this alliance have some other station. 
Order CXXXI. DATISCACEiE. 
Datisce.®, R. Brown in Denham, 25. (1826) ; Bartl. Ord. Nat. 419. (1830). 
Essential Character. — Floivers unisexual. Calyx of the males divided into several 
pieces ; of the females superior, toothed. Stamens several ; anthers 2-celled, membranous, 
linear, bursting longitudinally. Ovary 1 -celled, with polyspermous parietal placentae; 
stigmas equal in number to the placentae, recurved. Fruit capsular, opening at the vertex, 
1 -celled, with polyspermous parietal placentae. Seeds enveloped in a membranous finely 
reticulated integument, with a cupulate membranaceous strophiole ; embryo straight, with- 
out albumen, its radicle very long, turned towards the hilum. Cotyledons, very short. — Her- 
baceous branched plants. Leaves alternate, cut, compound, without stipules. Flowers in 
axillary racemes. 
Affinities. Brown, in deciding that Datisca has no affinity with Reseda, 
in which I now agree, does not say to what he supposes the order it represents 
to be allied. We must suppose, however, that Cannabis among Urticaceae was 
in his view. -So little is at present known of the other genera, that I can 
only leave it here with its character a little improved by Barthng. 
Geography. The very few species of which this order consists are scat- 
tered over North America, Siberia, northern India, the Indian archipelago, 
and the south-eastern corner of Europe. 
Properties. Datisca is bitter. 
GENERA. 
Datisca, L. 
Tetrameles, R. Br. 
, Tricerastes, Presl. 
