236 
GENTIANACE^!. 
1. EXACUMj Linn. 
Calyx 4-5-partite, with lanceolate winged or keeled divisions. 
Corolla rotate, with a globose tube, and 4-5-1 obed limb. Stamens 
4-5, inserted at the throat of the tube ; anthers dehiscing by ter- 
minal pores. Ovary 2-celled ; style decliuate ; stigma capitate. Fruit 
a globose membranous 2-valved capsule, with the placentas separating 
from the valves. — Herbs, usually annual, with flowers in terminal 
cymes. Distrib. Tropics of the Old World. Species 20. 
1. E. quinquenervium, Griseb. in DC. Prod. ix. 46. An erect gla- 
brous annual, with simple or forked stems a foot or more long. Leaves 
lanceolate or ovate-lanceolate, 1-2 in. long, acute, 3-5-nerved, narrowed 
to a short flattened petiole. Flowers in dichotomous terminal cymes, 
on erect in. pedicels. Sepals 5, free, lanceolate, acute, % in. long, 
acutely keeled. Corolla blue, half as long again as the calyx, with 
5 deltoid lobes. Capsule globose, i in. long, splitting into two 
membranous valves. 
Mauritius, near Piton du Milieu de lisle, Rome ! Also Madagascar and East 
Tropical Africa. 
2. LIMNANTHEMUM, Gmel. 
Calyx 5-partite, persistent. Corolla rotate, deciduous, the segments 
variously fimbriated. Stamens included, inserted at the throat of the 
corolla. Ovary sessile, 1-celled, surrounded by 5 hypogynous glands ; 
placentation parietal ; ovules numerous ; style cylindrical, persistent. 
Fruit a small membranous capsule. — Aquatic herbs, with floating 
leaves and umbellate flowers. Distrib. Round the world in the 
Tropics. Species 10-20. 
1. L. indicum, Griseb. in DC. Prod. ix. 139. A floating glabrous 
aquatic herb. Leaves round-cordate, not peltate, 2-4 in. broad, with 
a deep basal sinus ; petiole varying in length according to the depth 
of the water. Flowers many, in a sessile umbel from near the top of 
the petiole ; pedicels longer than the flowers. Sepals lanceolate, f in. 
long. Corolla twice as long as the calyx, with whitish segments, 
covered with white hairs down the face. Capsule globose, i in. broad, 
containing about a dozen white seeds ; style T V in. long. Villarsia in- 
dica, Vent. ; Hook. Pot. Misc. 3, t. 30. 
Mauritius, in the Mare aux Vacouas, Grand Bassin, and other lakes. Through 
the tropics of the Old World. 
Order LXXII. SCROPHULARIACE^l. 
Flowers irregular, hermaphrodite. Calyx persistent, inferior, divided 
part of the way down or to the base into 4-5 lobes. Corolla deciduous, 
with a cylindrical or funnel-shaped tube and a bilabiate limb. Stamens 4, 
inserted in the corolla tube, or 2 abortive, or represented by staminodes ; 
anther-cells 2, often divaricated. Ovary 2-celled, with axile placenta- 
