Lycaste flowers, like all orchid blooms, have three petals and three sepals. The petals are typically yellow, white, or orange, and the sepals are yellow, orange, green, or reddish brown. The petals and sepals may be marked sparsely or densely with red, reddish purple, purple, or reddish brown spots. The lip (ventral petal) may be very similar to the other two petals, as in Lycaste aromatica or Lycaste brevispatha, or colored quite distinctively, as in several subspecies and varieties of Lycaste macrophylla. Most Lycaste flowers are medium in size, averaging about 5 to 10 cm, but Lyc. schilleriana is 16–18 cm across. Some Lycaste blooms have a unique fragrance - the scent of Lyc. aromatica has been variously described as cinnamon or clove. The blooms of the species Lyc. cochleata, consobrina, and cruenta also have a pleasant scent.
The World Checklist of Selected Plant Families, maintained by the Royal Botanic Gardens at Kew, is recognized by the American Orchid Society as the definitive authority on orchid taxonomy. The Checklist currently acknowledges 31 species of Lycaste, 3 natural hybrids, 2 subspecies (and 1 nominate subspecies), and 1 variety. Orchid growers and orchid collectors, who tend to be taxonomic "splitters" more often than "lumpers" (see lumpers and splitters), recognize additional subspecies and varieties of Lycaste, as well as alba (white) forms of several species.
The Lycastes have been divided into four sections, one of which has two subsections:
All but two of the Deciduosae have spines at the apices of their pseudobulbs, that become exposed when the leaves are dropped - the exceptions are a Xanthanthae species, Lycaste lasioglossa, and a Paradeciduosae species, Lycaste tricolor. Both of these species lack spines, and may bloom when leaves are still present.
The recognized Xanthanthae species include:
The Paradeciduosae species include:
The Macrophyllae form a large complex, with subspecies and varieties that can be considered to be in the process of differentiating into new full species. The Macrophyllae species include:
The Fimbriatae species include:
Natural hybrids :
A revision of Lycaste, published in 2003 by Henry Oakeley and Angela Ryan, split off most of the species of section Fimbriatae as the new genus Ida. The 34 species of Ida occur in South America or in the Caribbean Islands (Ida barringtoniae), while true Lycastes occur mostly in Mexico and Central America. The genus Ida is recognized by the World Checklist of Monocotyledons.