Flora of Australia Vol. 37 has Montanoa as the only genus in Subfamily Asteroideae > Tribe Heliantheae > Subtribe Montanoinae.
Plants of the World Online recognises 29 species, Mabberley around 25 and Flora around 20.
Most are from Mexico and the north of South America.
Montanoa bipinnatifida and Montanoa hibiscifolia are sparsely naturalised in S. E. Queensland and very rarely seen in gardens here.
Many are small shrubs, some are like small trees up to 8 or 10 m high and a few are woody vines (lianas).
Stems can be round or square and parts have a sticky sap.
Smaller stems may have no hairs or sparse to dense simple ones and glands.
The opposite leaves are on petioles that may have wings or auricles (small lobes) on them.
Blades can be ovate, twice divided (bipinnate) or have up to 5 lobes from the base (palmate or like a hand).
The upper surface has no or a few hairs and the lower has sparse to dense ones.
Hairs can be simple, glandular, white or clear and of 1 or more cells.
The edge can be smooth or toothed and there are typically 3 main veins from the base.
Terminal flower heads or capitula can be simple but most are in branched clusters.
The erect or pendulous heads are on a smooth or hairy peduncle that may have small leaf-like bracts on it.
There are 3 (1 to 2) whorls of bracts or phyllaries in the basal involucre.
The lance-shaped to ovate bracts may be of equal or different lengths in each whorl.
Outer bracts can be green and leaf-like and the inner ones dry and membranous.
The outer surface may be smooth or hairy and there are often a lot of glands.
The receptacle holding the florets is flat or slight to markedly convex.
Surrounding each floret is one scale or palea that persists on the fruit.
Variously shaped, paleae usually have short hairs on the edge and often a long spine at the tip.
Initially green they grow as the ovary enlarges then become dry and papery.
There is 1 (0) row of white, cream or yellow neuter (sterile) ray florets.
The short corolla tube has an obovate ligule up to 3.5 cm long.
The ligule tip can be round, pointed or have 2 or 3 small lobes.
The inner surface sometimes has a few hairs but the outer usually has glands and hairs.
The few to many bisexual disk florets have a tubular base and 5 short pointed lobes.
The yellow or greenish corolla has glands and no to dense hairs on the outer surface.
The 5 stamen filaments are free and the anthers are loosely fused into a tube.
Each anther has small lobes at the base and a sterile ovate appendage at the tip.
The yellow or black style grows through the anther tube and splits into 2 linear branches that curve back.
Each branch has a linear stigma and tiny hairs.
The inferior ovary has one ovule.
The fruit are cypselae (dry one-seeded indehiscent fruit from an inferior ovary) but commonly called achenes (from a superior ovary).
The brown, reddish-brown to black, obovoid or 4-sided seeds may be laterally compressed.
There are no hairs but there is a ring or collar at the tip that may from a nectary.
The enlarged paleae, sometimes longer than the seeds, may fall off or remain on them.