Rubiaceae

Rubiaceae (Rubiaceae) are a family of plants commonly called the ruby, white gall, or coffee family. Other plants that are included are cinchona and gambir.

A number of formerly recognized families, "Dialypetalanthaceae", "Henriqueziaceae, "Naucleaceae" and "Theligonaceae", are now included as genera within the family Rubiaceae, following the guidelines of the APG "Angiosperm Phylogeny Group". There are now about 600 genera and more than 10,000 species in the Rubiaceae. The family is subdivided into three subfamilies; Rubioideae, Cinchonoideae, and Ixoroideae.

Description

They are trees, shrubs, suffrutices, herbs, vines or lianas, of terrestrial or rarely epiphytic habits, sometimes with raphides; plants generally hermaphroditic, sometimes dioecious or polygamous. Leaves opposite or sometimes whorled, blade entire or rarely pinnatifid (Pentagonia, Simira), sometimes with lesser vein clathrate (i.e., lineolate) or rarely finely ridged (Pentagonia); usually stalked; interpetiolar stipules and sometimes also intrapetiolar, or calyptrate or rarely free, persistent or deciduous, triangular, bilobed or setose, or rarely the stipules are foliaceous and indistinguishable from the leaves (Galium). Inflorescences terminal, pseudoaxillary (i.e., present only in one axil of a node, actually terminal, but apparently axillary due to sympodial growth of the axillary bud) or axillary, cymose, paniculate, spiciform, capitate or reduced to a solitary flower, usually bracteate, flowers actinomorphic or rarely slightly zygomorphic, calyx gamosepalous, (3) 4–5 (9); corolla gamopetalous, (3) 4–5 (9)-lobed; stamens epipetalous, alternate to cololine wolves and isomers, dithecal anthers or rarely pollen sacs divided into several locules by means of internal divisions; ovary inferior (Coussarea, Faramea), ovule 1 or several to numerous per locule, with placentation of various types; stigma simple or 2 (–8)-lobed; disc usually present. Fruit simple or rarely multiple and syncarpic (Morinda), abayado, drupaceous, capsular or schizocarpic; Seeds angular, rounded, flattened and/or winged or rarely with a tuft of trichomes (Hillia).

Distribution and habitat

Family with 10,000 species in 500–700 genera, cosmopolitan, but mainly tropical. The combination of the interpetiolar stipules, the opposite or whorled leaves, the gamopetal corolla and the inferior ovary is characteristic; only Cassipourea (Rhizophoraceae), Hedyosmum (Chloranthaceae) and Pilea (Urticaceae) also have interpetiolar stipules. Several Rubiaceae species have a pulvinulus (bulged when alive, constricted when dry) below the nodes on twigs, whereas this structure is found above the nodes in Acanthaceae. Some species are grown as ornamentals; useful products derived from Rubiaceae species include quinine, coffee, and the drug ipecacuanha. Cinchona pubescens Vahl, a species of shrubs and trees, was widely cultivated in Central America in humid forest zones at 500–1700 m and some trees still persist or are cultivated. No specimens of this species have been recorded from Nicaragua, but it is likely that it can be found, and is cited by Barrett (1994) and Coe and Anderson (1996) under the common names "Quina" and "Quinine". In the genus key, it would be identified as Ferdinandusa, from which it is distinguished by the flattened stipules and hippocrateriform corollas, yellow to red, bearded on the throat and with valve lobes. Deppea grandiflora Schltdl., a shrub or small tree species typical of humid or pine-oak forests at 1200–2900 m, has been recorded from Honduras and Costa Rica. In the genus key, it would be identified as Bouvardia, from which it is distinguished by its bright yellow, bell-shaped corollas and angular (i.e. non-winged) seeds. Pogonopus exsertus (Oerst.) Oerst. it has been recorded from dry forests of Honduras, El Salvador and southern Costa Rica. This species resembles Calycophyllum candidissimum, but is distinguished by the triangular and interpetiolar stipules and the usually pink petaloid calicine blades.

Synonymy

• Aparinaceae, Asperulaceae, Catesbaeaceae, Cephalanthaceae, Cinchoniaceae, Coffeaceae, Coutariaceae, Cynocrambaceae, Dialypetalanthaceae, Galiaceae, Gardeniaceae, Guettardaceae, Hedyotidaceae, Henriqueziaceae, Houstoniaceae, Hydrophylacaceae, Lippayaceae, Lygodisodaceae, Naucle