Rubiaceae

Plant Sex: Flowers bisexual.

Flowers: Actinomorphic, rarely zygomorphic. Stamens epipetalous, often with short filament. Gynoecium epigynous. Some members HETEROSTYLOUS.

Inflorescence: Cymose.

Fruits: Capsules, berries, drupes.

Habit: Herbs and shrubs, trees in the tropics. Some epiphytes & myrmecophytes (ant plants).

Leaves. Simple, opposite or whorled, entire. With INTERPETIOLAR STIPULES.

Examples:
Ixora

I. chinensis (flame-of-the woods). Node showing interpetiolar stipule. Inflorescence.

Pentas

P. lanceolata (star-cluster). Flowering plant. Inflorescence. Flower L.S. Flower L.S. apical part. Flower L.S. basal part.

Galium

G. aparine (bedstraw). Stem and leaves with retrorse trichomes.
G. odoratum. Flowering shoot. Flower L.S.
G. pilosum. Fruiting shoot. Fruits close-up showing retrorse trichomes.

Hedyotis

H. purpurea (bluets). Flowering plant. Inflorescence. Flowers.
H. pusila (bluets). Flowering shoots. Young fruits.

Cephalanthus

C. occidentalis (buttonbush). Habit of plant in flower. Inflorescences. Close-up of inflorescence.

Coffea

C. arabica (coffee). Coffee plants being grown under taller shade trees in Papua New Guinea. Flowering shoot. Fruiting shoot.

Cinchona

C. pubescens (quinine). Flowering shoot.

Gardenia

G. jasminoides (gardenia). Flowering branch.
G. cornuta. Flowering shoot (from S. Africa).
G. thunbergii. Bizarre fruits of this plant from the Kirstenbosch Bot. Garden in Capetown S. Africa.

Hydnophytum

H. formicarum (ant plant). Habit of the epiphytic plant. Cut stem to show ant chambers. Flowering and fruiting plant in cultivation.
H. moseleyanum. Epiphytic plant removed from tree to show swollen base (with ant chambers). Close-up of flower.

SIUC / College of Science / Elements of Plant Systematics
URL: http://www.plantbiology.siu.edu/PLB304/Lecture21Solan/Rubiaceae.html
Last updated: 10-Apr-08 / dln