Entomophilous and protandrous. About 500 species, especially
in the Tropics; in this country, _L. dortmanna_ (margin of
lakes).--Several are cultivated in gardens and conservatories as
ornamental plants (_Lobelia bicolor_, _erinus_, _fulgens_, etc.,
_Siphocampylos_, _Centropogon_). The latex of several species
of _Tupa_ is poisonous; caoutchouc is also obtained from them.
OFFICINAL: “herba _Lobeliæ_” (the alkaloid lobeline) from the
poisonous _L. inflata_ (N. Am.).
Order 4. =Goodeniaceæ.= Chiefly Australian (200 species),
closely related to Orders 3 and 5, but without latex. The style
is provided with a “collecting-cup” which receives the pollen
before the flower opens; it has a small, hairy aperture through
which the pollen is forced out by the stigmas, and through
which they emerge when the pollen is shed; it is sensitive and
exhibits movements when touched.--Herbs, under-shrubs, less
frequently shrubs. _Goodenia_, _Leschenaultia_, _Scævola_.
Order 5. =Stylidiaceæ= (or =Candolleaceæ=); 100 species,
the majority Australian; zygomorpbic flowers, but with the
ordinary position. The anterior petal is very small. The chief
characteristic feature is the presence of only 2 stamens (with
extrorse anthers) which are united with the style and form a
_stylar-column_; this is bent like a knee and sensitive at
the bend to such a degree that when touched it jerks violently
across the flower to the opposite side and then loses its
sensitiveness.--Herbs, less frequently under-shrubs. _Stylidium_
(_Candollea_).