[2] Among them are several familiar garden plants belonging to the genera Campanula (bellflower), Lobelia, and Platycodon (balloonflower).

Most current classifications include the segregate family Lobeliaceae in Campanulaceae as subfamily Lobelioideae.

A third subfamily, Cyphioideae, includes the genus Cyphia, and sometimes also the genera Cyphocarpus, Nemacladus, Parishella and Pseudonemacladus.

Although most Campanulaceae are perennial herbs (sometimes climbing, as in Codonopsis), there is also a large number of annuals e.g. species of Legousia.

Many perennial campanuloids grow in rock-crevices, such as Musschia aurea (Madeira) and Petromarula pinnata (Crete).

Some lobelioids also grow on rocks, e.g. the peculiar perennial stem succulent Brighamia rockii in Hawaii.

When, in addition, the plant is unbranched, the result may be a palm- or treefern-like habit, as in species of the Hawaiian genus Cyanea, which comprises the tallest of Campanulaceae, C. leptostegia (up to 14 m).

In the Himalaya Campanula modesta and Cyananthus microphyllus reach even higher, probably setting the altitudinal record for the family at 4800 m. Several species are associated with freshwater, such as Lobelia dortmanna, an isoetid common in oligotrophic lakes in the boreal zone of North America and Europe, and Howellia aquatilis, an elodeid growing in ponds in SW North America.

Blue of various shades is the most common petal colour, but purple, red, pink, orange, yellow, white, and green also occur.

Anthers may be fused into a tube, as in all species of Lobelioideae and some Campanuloideae (e.g. Symphyandra) Within the family pollen grains are often tricolporate, less commonly triporate, tricolpate, or pantoporate.

During flowering, it is pushed up by the elongating style and "presented" to visiting pollinators at the apex of the tube, a mechanism described as a pollen pump.

[4] Campanuloideae Lobelioideae Cyphioideae Cyphocarpoideae Nemacladoideae The earliest known occurrence of Campanulaceae pollen is from Oligocene strata.

[5] Earliest Campanulaceae macrofossils dated, are seeds of †Campanula paleopyramidalis from 17-16 million years old Miocene deposits in the Nowy Sacz, Carpathians, Poland.