Maxillaria (Ruiz & Pav., 1794) is a large genus of orchids in the family Orchidaceae, currently treated in a broadly circumscribed sense that encompasses well over 600 accepted species and synonymises more than 40 former genera. Plants are found across a sweeping arc of the Neotropics, from central Mexico south to Bolivia and Argentina, including the West Indies, at elevations ranging from sea level to approximately 3,500 metres.
The vegetative structure is characteristic of many New World epiphytic orchids: round to oblong pseudobulbs arise from a sympodial rhizome and support one or two lanceolate leaves. Growth habit varies considerably — some species cluster densely on short rhizomes, while others space their pseudobulbs along elongate rhizomes covered in silvery-grey velamen. The vast majority of species grow as epiphytes on the branches and bark of rainforest trees, though a small number are terrestrial or lithophytic.
Flowers arise singly on short peduncles from the base of the pseudobulbs. Floral form is highly diverse: petals and sepals are free, the labellum is curved and firmly attached to the column base with three lobes of varying prominence, and papillae on the lip typically take conical forms with rounded or pointed tips. Flower size ranges from tiny to large and showy. Fragrance is a notable trait in certain species — Maxillaria tenuifolia is particularly well known among growers for its sweet coconut-pie scent.
The genus carries a broad vernacular range: "tiger orchid," "spider orchid," and "flame orchid" all appear in common usage, though none is universally applied. The name Maxillaria itself is derived from the Latin maxilla (jawbone), alluding to the resemblance between the column and lip base in some species and a protruding jaw.
Etymology
The generic name Maxillaria is derived from the Latin word maxilla, meaning jawbone. The allusion is to the distinctive morphology of certain species in which the column and the base of the lip together create a shape reminiscent of a protruding jaw. The genus was formally described by the Spanish botanists Hipólito Ruiz López and José Antonio Pavón Jiménez in their 1794 work Florae Peruvianae et Chilensis Prodromus (published as Fl. Peruv. Prodr.: 116).
Distribution
Maxillaria is a predominantly Neotropical genus. Its range extends from central Mexico through Central America and the Caribbean islands, continuing through the Andes and into Bolivia and northern Argentina, with a broad presence throughout tropical South America including Brazil (recorded from central, eastern, northeastern, and southern regions), Colombia, and adjacent countries. Additional national records include Belize, Costa Rica, Cuba, Bolivia, and Argentina. Elevational tolerance is unusually wide: species are documented from sea level up to approximately 3,500 metres in montane cloud forests and páramo-adjacent habitats, resulting in markedly different temperature regimes across the genus — from warm-growing lowland epiphytes to cold-tolerant high-altitude taxa.
Ecology
Most Maxillaria species are epiphytes, growing on the bark and branches of trees in humid tropical and subtropical forests. A minority are terrestrial or lithophytic — M. rupestris is a noted lithophyte. The wide elevational range (sea level to 3,500 m) means that the genus spans warm, intermediate, and cool growing conditions, making broad generalisation about its ecology difficult. Fragrance in the flowers of some species suggests bee or moth pollination, though detailed pollination biology has been documented for only a limited number of taxa.
Cultivation
Maxillaria as a group is not widely grown as a general horticultural subject, largely because the majority of species produce modest-sized or inconspicuous flowers. Within specialist orchid collections, however, particular species attract dedicated interest. Maxillaria tenuifolia — the coconut orchid — is among the most frequently cultivated, prized primarily for the strong coconut fragrance of its burgundy-red flowers rather than for visual impact alone. The wide elevational and geographic range of the genus means that cultivation requirements vary considerably by species: warm-growing lowland species require minimum temperatures above 18 °C, while high-altitude taxa tolerate and often prefer cooler, intermediate conditions with marked day–night temperature differentials.
Taxonomy Notes
Maxillaria was established by Ruiz & Pav. in 1794 and for most of its history was treated as a moderately sized epiphytic orchid genus. A pivotal 2007 molecular phylogenetic study of subtribe Maxillariinae revealed that many contemporaneous genera were nested within Maxillaria, rendering the genus as then delimited polyphyletic. The study proposed dissolution into 17 separate genera; however, a conservative alternative — expanding Maxillaria to absorb all embedded lineages — has gained traction and is followed by Plants of the World Online, which as of December 2023 lists more than 40 genus names as synonyms. These include: Adamanthus, Anthosiphon, Brasiliorchis, Camaridium, Christensonella, and others. GBIF records 870 total descendant taxa under the accepted concept. The taxonomic boundary of the genus remains an area of active discussion, with some authorities preferring the segregate treatment.
