90 EUCALYPTS CULTIVATED IN THE UNITED STATES. 



west. Not until they fruit, however, will their identity be fully estab- 

 lished. As stated before, it was thought best to discuss in detail in 

 the preceding pages only those species that have been positively 

 identified in the Southwest by means of their flowers and seed-cases, 

 leaving the other arboreal species to be mentioned only in this 

 botanical section. 



SYSTEMATIC POSITION OF THE EUCALYPTI. 



The Eucalypti belong to the family Myrtacese, which may be char- 

 acterized as follows : 



Trees or shrubs; leaves opposite or alternate, usually dotted; flowers regular cr 

 nearly so. Calyx-tube grown to the ovary at the base or up to the insertion of the 

 stamens. Petals usually as many as calyx-lobes, very much imbricated in the bud, 

 the external one sometimes larger than the others, but usually all nearly equal when 

 expanded, sometimes all concrete and falling off in a single operculum, or rarely 

 entirely wanting. Stamens indefinite, usually numerous, inserted in one or several 

 rows on a disk; filaments free or rarely united into a ring or tube at the base, or 

 into as many bundles as there are calyx-lobes; anthers 2-celled, versatile, or attached 

 by the base, the cells open in longitudinal slits, or rarely in terminal pores. Ovary 

 inclosed in the calyx-tube, sometimes 1-celled, with a placenta attached to the 1 >ase 

 or adnate to one side; more frequently 2 or more celled, with the placentas in the 

 inner angle of each cell; very rarely 1-celled with 2 parietal placentas. Style simple, 

 with a small capitate or lobed stigma. Ovules 2 or more to each placenta, in 2 or 

 more rows, or very rarely solitary. Fruit adnate to the calyx-tube, capsular and 

 opening at the summit in as many valves as cells, or indihescent, dry and 1-seeded, 

 or succulent and indihescent. Perfect seeds usually very few or solitary in each cell, 

 even when the ovules are numerous, or rarely numerous and perfect. 



The family is divided into four tribes, the Eucalypti falling into the 

 tribe Leptosperma? (meaning "small seeds"), the chief characteristic 

 of which is its 2 to 5 celled ovary opening at the summit by as many 

 valves as there are cells. Of the genera belonging to this tribe, the 

 genus Eucalyptus is by far the largest, including about 150 known 

 species. This genus was first described by the French botanist 

 L'Heritier in 1788. The first species discovered and described by him 

 was Eucalyptus obliqua. 



BOTANICAL DESCRIPTION OF GENUS. 



Eucalyptus L'Her. 



Evergreen trees, scattered as well as gregarious, sometimes of enormous height, 

 some dwarfed shrubs, present in all parts of Australia in intratropic lowlands, in 

 arid desert sands, ami in alpine situations, occurring more scantily in New Guinea, in 

 Timor, and very rarely in the Moluccas. Mostly of rapid growth, flowering occa- 

 sionally at a very early age; bark either completely persistent or its outer layers 

 deciduous; matured wood always hard; main branches usually distant; foliage often 

 not dense; branches frequently pendent, usually quite glabrous, sometimes those of 

 young plants rough, hairy. Leaves of old plants usually glabrous and thick in tex- 

 ture, usually scattered and with conspicuous stalks, in a few species opposite, and 

 then generally without stalks, sometimes united; leaves of young plants frequently 

 different in texture, position, and shape from those of older plants; the latter gener- 

 ally approaching in form to lanceolar-sickle-shapeil, tin- upper and lower surfaces 



