2 FLORA OF SOUTH AUSTRALIA. 
Sub-Class IV.—Synpetaleae Hypogynae. 
Petals united, rarely distinct or absent. Ovary superior, free from the 
calyx. Stamens inserted on the corolla, or rarely at the base of the ovary. 
DIVISION II.—GYMNOSPERMS. 
Flowers strictly unisexual, without calyx or corolla. Stigma absent ; 
ovules naked, in the axils of scales forming a cone. Cotyledons, two or 
more, 
CLASS II.—MONOCOTYLEDONS. 
Embryo with one seed-lobe. Floral organs usually in threes. Veins of 
leaves mostly parallel and longitudinal. Woody stems without distinct 
pith, concentric woody layers and bark. 
Sub-Class I.—Florideae Perigynae. 
Flowers with calyx and corolla; ovary inferior, adnate to the calyx. 
(Corolla absent in some Hydrocharideae). 
Sub-Class II.—Florideae Hypogynae. 
Flowers with a calyx, corolla often absent. Stamens inserted at the 
base or below the ovary. 
Sub-Class III.—Glumiferae. 
Flowers without a conspicuous calyx, subtended by bracts. Stamens 
inserted at the base or below the ovary. 
CLASS IJJ.—VASCULAR ACOTYLEDONS. 
No true flowers or seeds. Embryonic plant consisting of minute frond- 
like structure (prothallus) bearing male organs (antheridia) and female 
organs (archegonia); the adult plant provided with leaves or fronds bearing 
spore-cases (sporangia) containing spores which originate a prothallus. 
