Maxillaria, abbreviated as Max in horticultural trade, is a large genus of orchids (family Orchidaceae). This is a diverse genus, with very different morphological forms. Their characteristics can vary widely. Several species form a complex. All this gives the impression that the current state of the taxonomy of this genus needs a thorough review.
They are commonly called Spider Orchid, Flame Orchid or Tiger Orchid. Their scientific name is derived from the Latin word maxilla, meaning jawbone, reflecting on the column and the base of the lip of some species, that may evoke a protruding jaw.
They are distributed in the rainforest at sea level to elevations of 3,500 m, of the neotropical zone (tropical and subtropical America). This is an indication for the different temperature requirements, from warm growing to cold growing, within the genus.
They are mostly epiphytes, rather large in size, but some are terrestrials or even lithophytes (such as M. rupestris). But the showy Brazilian orchid Maxillaria picta can equally be found in the higher parts of a tree as found growing on rocks, as long as the humidity of the air is high enough.
Many species are rather large with rampant growth.
Their pseudobulbs are round or oblong and each carry one or two lanceolate leaves. Some grow close together in a clustered manner on a short rhizome, while in other species the pseudobulbs keep some distance on an elongate rhizome. This rhizome is clothed in a somewhat transparent, silvery-gray velamen.
The flowers grow solitary on short stalks, called scapes, from the base of the pseudobulb. Most are small to very small, but some species carry large, showy flowers. The flowers are never longer than the leaves. Their free petals and sepals have a typically curved and adnate labellum with three inconspicuous lobes. Or the lip may have a distinct callus on the disc (= central part of the lip from which the lobes radiate). The papillae (= small warts like glands) and the trichomes of the lip show great diversity. The most common form for the papillae is the conical form with rounded or pointed tips.
The Maxillaria can be divided in two groups, according to the attachment of the lip to the column foot :
Maxillaria is not one of the popular genera among growers. Only a few species grow big, showy flowers. But some species are nevertheless sought by collectors, mostly for the fragrance of their blossoms, such as the Coconut orchid (M. tenuifolia). No black orchid has ever been grown yet, but Maxillaria schunkeana is probably the closest to it. Its color is actually a very dark purple-red, giving the impression of a black flower.