Also known as the Lobeliaceae family there are 94 genera recognised by Plants of the World Online (Kew) and
around 2319 (900 to 2380) species.
Australia has 6 or 7 genera with 70 to 80 species of Bluebells. S. E. Queensland has 4 genera with 20 species.
Many are used as garden plants or cut flowers including Lobelias and some of the hundreds of Campanula species.
It is variously divided into subfamilies with nearly all the species being in Campanuloideae and Lobelioideae.
Most are annual to perennial herbs with a few small shrubs and trees.
Many have a milky sap in the stems and leaves.
Most species have simple alternate leaves with or without a petiole.
Blades can be ovate, round, lance-shaped or linear.
Edges often have blunt or pointed teeth with water pores (hydathodes).
A few species have variously dissected leaves.
Blades also often have simple hairs, stomata and cystoliths (calcium deposits).
Terminal or axillary inflorescences can be a solitary flower or variously arranged clusters.
The mostly bisexual flowers can be regular or irregular in shape.
There are 5 (3 or 10) sepals with their bases almost always fused to the ovary.
Basal appendages may be present.
The 5 (4 or 10) petals, alternating with the sepals, have their bases fused to the sepals.
Some flowers have a flattish star-shaped corolla but most have a bell or funnel-shaped corolla tube with usually 5 lobes.
Lobelioideae are bi-labiate with 3 lobes in the upper lip and 2 in the lower but flowers are resupinate (upside down)
due to the pedicel (flower stalk) twisting so appear to have 2 upper and 3 lower lobes.
Most flowers are blue with some white, purple, pink or red and 2 species have yellow flowers.
There are as many stamens as there are corolla lobes – usually 5.
They are inserted at the base of the corolla or onto a nectary disc.
The filaments are free of each and usually have a wide basal appendage with short hairs.
The anthers can be free or erect with their edges touching or fused to form an anther tube.
The basifixed anthers open inwards with the pollen being collected by the style as it grows through the tube.
The almost always inferior or part-inferior ovary has 2, 3 or 5 fused carpels.
There are a similar number of locules or up to 10 due to the presence of false partitions or septae.
The numerous ovules have axile placentation and rarely parietal (to the wall).
There is 1 style with pollen collecting hairs at the top.
There are 2, 3 or 5 stigmas.
The fruit are mostly capsules with the sepals still attached.
They open variously – at the septae or into the chambers and through a long slit, valves or pores.
The small seeds are sometimes winged.
Berries are rare.