EUCALYPTUS. 



L'Heritier; sertum Anglioum 18, t. 20 (1788). 



Systematic Position. — Order Myrtaceaa ; tribe Leptospermese. 



Chakacteeistics of the Genus. — Calyx of firm consistence, by transverse fissure or more 

 rarely by across-rupture separated into a lower persistent more or less tubular or semiovate or 

 hemispheric portion and into a deciduous lid. Petals none, unless represented in some few species 

 by an inner separate or separable opercular membrane. Stamens very numerous, inserted close to 

 the edge of the calyx-tube in several rows, all fertile or some of the outer by absence of anthers 

 sterile, all free or rarely united at the base into four bundles, always finally deciduous ; filaments 

 thread-like, pointed, all inflexed while in bud or rarely the outer or very seldom all filaments 

 straight before expansion ; anthers dorsifixed, their two cells parallel or divergent, each opening 

 by a marginal or anterior slit or less commonly by a pore ; poUengrains tetrahedrons, smooth, 

 with longitudinal apertures. Style filiform ; stigma convex or almost flat, undivided, seldom much 

 dilated beyond the summit of the style. Ovary 3-6-celled, very rarely or quite exceptionally two- 

 celled ; its lower portion adnate, its upper portion more or less free. Ovules in each cell numerous, 

 spreading from an axile elongated narrow placenta in two or more rows, the greatest majority 

 remaining unfertilized. Fruit consisting of the variously enlarged indurated and truncated or 

 rarely four-toothed calyx-tube and an hardened inferiorly adnate capsule ; the latter with 3-5 

 rarely 2 or 6 wholly or partially exserted or entirely enclosed valves and with a thick central 

 somewhat columnar or rarely pyramidal axis. Seeds numerous, but comparatively few fertile ; 

 testa of these thin, generally without any appendage, or that of some species expanded into a 

 membranous large terminal appendage, or that of other species forming narrow membranes along 

 the angles of the seeds. Hilum ventral or basal. Embryo of amygdaline consistence. Cotyledones 

 broad, much compressed, somewhat folded, undivided or bibbed, curved around the cylindrical 

 straight erect radicle. 



Evergreen trees, sporadic as well as gregarious, sometimes of enormous height, or tall or 

 rarely dwarfed shrubs, copiously present in all parts of Australia even in intratropic low lands or iu 

 arid desert-sands or on alpine elevations, more scantily occurring in New Guinea, in Timor and very 

 rarely in the Moluccas, mostly of rapid growth, flowering occasionally at a very early age ; stem 

 not rarely kinofluous ; bark either completely persistent or its outer layers variously seceding ; 

 matured wood always particularly hard ; main branches usually distant ; foliage often not densely 

 shady; branchlets frequently pendent, quite glabrous or sometimes those of juvenile plants 

 rough-hairy or rarely so also those of advanced plants ; leaves of aged plants nearly always 

 glabrous and thick_in„ texture, never soft-hairy, often scattered and conspicuously stalked or in 

 some species opposite and then generally sessile or very rarely in pairs connate ; those of very 

 young states of the plant frequently difi'erent in texture, position and shape to those of the more 

 aged plants ; these latter prevailingly approaching in form to lanceolar-sickleshaped, often of equal 

 color as well as stomatiferous on both sides and turning one edge towards the zenith and the 

 other towards the ground ; much less frequently considerably darker above, and then often 

 stomatiferous only on the lower side and spreading horizontally ; oil-dots pellucid or concealed ; 

 peculiarly and strongly odorous ; primary veins often copious and much spreading ; insertion on 

 the leaf-stalk in very few species and particularly in their very juvenile state suprabasal; 

 inflorescence either axillary or terminal or more rarely both modes united or partially lateral ; 

 flowers in single or paniculated umbels or much less commonly two only together or quite solitary ; 



