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 Lucalypti belong to the family Myrtaceze, 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 piacenta attached to the base 
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 Kucalypti falling into the 
tribe Leptospermee (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’Héritier in 1788. The first species discovered and described by him 
was Lucalyptus 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, and 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, usuaily 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-shaped, the upper and lower surfaces 
