84 
FLORA OF ADEN. 
sometimes solitary. Petals usually wanting or small. Stamens definite 
or indefinite, perigynous or hypogynous. Disk 0 or annulate. Ovary 
usually free, 2-5-celled. Fruit usually capsular. 
XXIV. Umbellifera, (Ptychotis).— Leaves alternate, compound. 
Umbels axillary. Calyx-tube adnate to ovary. Petals 5, minute, dist- 
inct, epigynous. Stamens 5, epigynous. Fruit 2-celled, separating 
into 2 indehiscent 5-costate mericarps. 
II. — Gamopetaljs. 
Flowers usually bisexual, as a rule with both calyx and corolla. 
Corolla gamopetalous. 
Series 1. — Epigyna. 
XXV. Rubiacece. — Leaves opposite ; stipules adnate tojthe petiole. 
Flowers bisexual, regular. Calyx-tube adnate to ovary. Corolla inserted 
round the epigynous disk. Stamens inserted on the corolla-tube, alter- 
nating with its lobes. 
XXVI. Composites. — Leaves as a rule alternate ; stipules 0. In- 
florescence a dense head of many small flowers, sessile on a broad recept- 
acle and enclosed in an involucre of whorl ed or imbricate bracts. Calyx 
usually a pappus of hairs on the top of the ovary. Stamens on the 
corolla-tube ; anthers usually connate, connective produced upwards. 
Series 2. — Hypogynee. 
XXVII. Plumbaginaceee . — Leaves alternate, entire. Flowers regular, 
bisexual, pentamerous sheathed by bracts. Calyx 5-ribbed. Ovary 
1-celled ; ovule 1. 
XXVIII. Salvacloracece . — Glabrous shrubs or trees. Leaves opposite, 
entire. Stipules minute. Flowers small, tetramerous. Corolla mem- 
branous. Ovary free. 
XXIX. Apocynacece (Adenium). — Stem globose. Leaves entire, 
crowded at the end of the branches. Flowers regular, bisexual, pen- 
tamerous. Stamens 5, inserted in the corolla-tube. Carpels 2, distinct. 
Seeds comose ; albumen scanty. 
XXX. Asclepiaclaeece. — Ueaves entire, as a rule opposite. Stipules 0, 
Flowers regular, bisexual, pentamerous. Calyx inferior, sepals imbricate 
in bud. Stamens 5, inserted on the base of the corolla ; anthers 
cohering or connate, enclosing the stigma, pollen-grains as a rule 
united into waxy masses. Corona corolline or staminal. Carpels 2, 
distinct. Seeds usually winged and surmounted by a dense brush of 
hairs. Embryo large, in copious endosperm. 
