[3] Their leaves are generally heart-shaped or kidney-shaped, or are characteristically diplophyllous (the auricles of the leaf blades form distinctly inflexed appendages).

[2] Caltha species are hairless, dwarf to medium size (1–80 cm high) perennial herbs, with alternate leaves.

The flowers are single on a short stalk in the middle of the rosette of basal leaves (Southern Hemisphere species) or in a mostly few-flowered corymb, without or with one or few mostly sessile leaflike stipules.

Northern Hemisphere species have kidney to (elongated) heart-shaped leaves and stipules, with simple toothed or scalloped margins.

The actinomorphic flowers lack true petals and nectaries, but the five to nine (sometimes as little as four or as much as thirteen) sepals are distinctly colored yellow (rarely orange or red) to white (sometimes tinged pink or magenta).

howellii that has pollen with rounded apertures all over the surface (pantoporate) or an intermediate type (pantocolporate), and in C. palustris var.

These mostly develop into sessile follicles, with elliptic to globular light brown to black seeds without wings, dependent on the species between ½–1½ mm.

Plants with flowers only consisting of many rows of sepals are often in cultivation and are known under various names, among which are c.v. “Multiplex”, "Semiplena" or “Flore Plena”.

The oldest description that is generally acknowledged in the botanical literature dates from 1700 under the name Populago by Joseph Pitton de Tournefort in part 1 of his Institutiones rei herbariae.

Populations on the US westcoast and the US Rocky Mountains consistently differ from each other by fixed combinations of these character states and two subspecies are distinguished: ssp.

For this reason the subspecies status is generally preferred over distinguishing a separate species (Caltha biflora).

Some character states gradually change over its distribution area, and the angle of the basal lobes does not seem to be special in this respect.

[2] The generic name Caltha is derived from the Ancient Greek: κάλαθος (kalathos), meaning "goblet", and is said to refer to the shape of the flower.

[8] Caltha species are found in the cold and temperate regions of the Northern Hemisphere, the Andes and Patagonia, and alpine areas in Australia and New Zealand.

C. palustris has the widest distribution and is present in the cold and temperate regions of the Northern Hemisphere, but cannot be found in the Western United States.

C. sagittata is another species that occurs in moist alpine meadows, in this case from Colombia to Tierra del Fuego, growing at less altitude further from the equator.

This species contains a number of noxious chemicals such as anemonin, a trait it shares with other ranunculids, and this is probably the reason members of the entire family are avoided by vertebrate animals.

[11][12] When ripe follicles open, they form a "splash cup" from which seeds are expelled if raindrops hit them at the right angle.

[13] C. palustris seeds also have some spongy tissue that makes them float on water, until they wash up in a location that may be suitable for this species to grow.