CXX. OASUAEINE^. 1189 



Oeder CXX. CASUARINEiE. 



Flowers unisexual, the males in cylindrical spikes, the females in globular or 

 ovoid spikes or cones, both sexes sessile and solitary in the axils of whorled 

 bracts, the bracts of each whorl united into a toothed sheath enclosing the base 

 of the whorl of flowers, each flower within 2 small persistent bracteoles placed 

 right and left. Male flower : Perianth of 1 or 2 (aiiterior and posterior) concave 

 or hood-shaped segments, breaking off at their narrow base as they are forced off 

 by the development of the stamen. Stamen 1, the filament folded in the bud, 

 erect and exserted from the sheath of bracts when fully out. Anther with 2 

 large distinct cells, placed back to back, and opening in 2 valves. Female 

 flower : Perianth none. Ovary minute, 1 -celled. Style very shortly entire, with 

 2 long filiform stigmatic branches. Ovules 2, collateral, semi-anatropous, 

 laterally attached above the base of the cell. Fruit a globular ovoid or cylindrical 

 compact cone, formed of the enlarged thickened more or less woody bracts and 

 bracteoles, the bracteoles closed against each other over the unripe nut, often 

 protruding beyond the bracts, and opening as 2 valves when ripe. Nut much 

 compressed laterally, smooth and shining, produced at the apex into a 

 membranous often transparent wing, traversed longitudinally by an opaque 

 nerve (the base of the style). Seeds solitary, erect, laterally attached by a 

 funicle showing at its apex the second abortive ovule ; testa membranous ; no 

 albumen ; embryo with 2 large flattened cotyledons and a small superior radicle. 

 — Trees or shrubs, with leafless wiry or rigid erect or pendulous branches and 

 usually numerous deciduous verticillate branehlets, often articulate at the nodes. 

 Leaves replaced by very small scales in whorls of 4 to 16 often united at the 

 base, their midribs decurrent to the next node forming so many ribs or angles 

 to the internode ; the scales of each node alternating with those of the nodes 

 immediately below and above, so that when the internodes are very short (as in 

 the inflorescences), then the bracts, axillary flowers, &c., are superposed in twice 

 as many series as there are parts of each whorl. Male spikes terminating 

 deciduous branehlets, or almost sessile along the permanent branches, the female 

 cones usually sessile or only shortly pedunculate, but in both sexes there are 

 always 1, 2 or more barren internodes and sheaths below the flowering ones. 

 The number of parts of each whorl, whether on the branches, branehlets, spikes, 

 or cones, are the same in the same plant, or rarely fewer on the weaker branches 

 and branehlets than on the stronger ones. Anthers and style-branches usually 

 purple or red, the latter elegantly fringing the female flower-cones. 



The Order consists but of a single genus, chiefly Australian, but extending also over tropical 

 Asia from East Africa to the Indian Archiijc'iigo and South Pacific Islands. 



1. CASUARINA, Linn. 



(Pendent branehlets resembling the feathers of the Cassowary.) 

 Character and distribution the same as those of the Order. 



Sect. I. IiSiopltys. — Whorn-lQ-merous, rarely G-merous. Cone-values usually prominent, 

 thickened and keeled or angled on the back or with a short hroad and smooth dorsal protuberance. 



Whorls usually 10-12-merous (varying 9 to 16). Cone-valves thickened 

 into a dorsal angle or keel. 

 Branches terete. Male-spikes not exceeding lin. Cones about Jin. 



diameter, the eones villous on the back 1. C glauca. 



Wiorls usually 7-merous (varying 5 to 8).- Cone-valves usually with 

 a short transverse dorsalappendage sometimes very shortorohsolete. 

 Male spikes cylindricaj imbricate. Cones nearly globular, the 



valves pubescent on the back 2. C equiselifolia. 



Male-spikes moniliform. Cone usually oblong or small, the valves 

 glabrous. Branehlets very slender. 

 Cones Jin. diameter or more, usually oblong 3. C subcrosa 



