The Families of Flowering Plants

L. Watson and M. J. Dallwitz


Rubiaceae Juss.

Including Aparineae (Aparinaceae) Hoffmgg. & Link, Dialypetalanthaceae, Cinchonaceae Lindl., Coffeaceae J.G. Agardh, Galiaceae Lindley, Gardeniaceae Dum., Lippayaceae Meissner, Lygodysodeaceae Bartl., Operculariaceae Dum.

Excluding Henriqueziaceae, Naucleaceae

Habit and leaf form. Trees and shrubs (mostly), or lianas, or herbs (then mostly with tetragonous, knotted stems); non-laticiferous and without coloured juice. Plants non-succulent. Self supporting, or epiphytic, or climbing. Helophytic, or mesophytic, or xerophytic, or hydrophytic (Limnosipanea). Leaves opposite (nearly always, and decussate), or whorled (or at least ostensibly so, seemingly representing paired leaves with enlarged, leaflike interpetiolar stipules — and rarely ostensibly alternate, through suppression of one member of each pair); petiolate to sessile; connate (often, via the stipules), or not connate; gland-dotted, or not gland-dotted; simple; epulvinate. Lamina entire; one-veined, or pinnately veined; cross-venulate. Leaves stipulate. Stipules interpetiolar (usually), or intrapetiolar; with colleters (typically). Lamina margins entire, or serrate. Leaves without a persistent basal meristem. Domatia recorded (frequently), or not recorded; represented by pits (mostly), or pockets, or hair tufts.

General anatomy. Plants with ‘crystal sand’ (very commonly), or without ‘crystal sand’.

Leaf anatomy. Stomata typically paracytic. Hairs present (often septate in Rubioideae, not septate in Cinchonoideae and Guettardoideae).

Lamina dorsiventral (nearly always), or centric (rarely). The mesophyll with sclerencymatous idioblasts, or without sclerenchymatous idioblasts; containing calcium oxalate crystals. The mesophyll crystals raphides present in Rubioideae, absent from Cinchonoideae and Guettardoideae. Minor leaf veins with phloem transfer cells (5 genera — Asperula, Galium, Phuopsis, Rubia, Sherardia), or without phloem transfer cells (20 genera, e.g. Coprosma, Cinchona, Coffea, Gardenia, Hoffmannia, Ixora, Pavetta, Randia).

Stem anatomy. Young stems tetragonal. Cork cambium present, or absent (e.g. in Galieae); initially deep-seated, or superficial. Nodes unilacunar, or tri-lacunar. Internal phloem absent. Secondary thickening developing from a conventional cambial ring (nearly always), or anomalous (concentric cambia recorded only in Basanacantha, ‘Chiococca’); via concentric cambia. ‘Included’ phloem present (Basanacantha), or absent. Xylem with tracheids; with fibre tracheids; with vessels. Vessel end-walls mostly simple. Vessels with vestured pits. Wood parenchyma apotracheal, or paratracheal.

Reproductive type, pollination. Plants hermaphrodite (usually), or monoecious, or polygamomonoecious, or dioecious (e.g. Coprosma); often heterostylous. Entomophilous. Pollination mechanism conspicuously specialized (via stylar modifications for passive pollen presentation), or unspecialized.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’, or solitary (less often); in cymes, or in panicles, or in verticils, or in heads (rarely, e.g. Morindeae, Gardenieae). The terminal inflorescence unit cymose. Inflorescences with involucral bracts (when capitate), or without involucral bracts; pseudanthial, or not pseudanthial. Flowers small, or medium-sized; regular; mostly 4 merous, or 5 merous; cyclic; tetracyclic. Free hypanthium absent.

Perianth with distinct calyx and corolla, or petaline (the calyx often absent or almost so); 7–15; 2 whorled, or 1 whorled; the two whorls isomerous. Calyx when detectable 4, or 5; 1 whorled; polysepalous (but epigynous), or gamosepalous (the lobes varying from practically lacking to enlarged and brightly coloured); when gamosepalous, entire, or lobulate, or blunt-lobed, or toothed; regular (mostly), or bilabiate (rarely), or unequal but not bilabiate (sometimes with one, or several, enlarged members); persistent, or not persistent; accrescent, or non-accrescent; open in bud (commonly), or contorted, or valvate. Epicalyx present (e.g. Fernelia, Flagenium), or absent. Corolla (3–)4, or 5, or 8–10; 1 whorled; gamopetalous; imbricate, or valvate, or contorted; tubular, or hypocrateriform; regular, or bilabiate (rarely).

Androecium 4, or 5. Androecial members adnate (to the corolla tube, or attached at its very base in Coprosma); free of one another (usually), or coherent (occasionally, via the anthers, e.g. Argostemma); 1 whorled. Androecium exclusively of fertile stamens. Stamens 4, or 5; inserted near the base of the corolla tube, or midway down the corolla tube, or in the throat of the corolla tube; isomerous with the perianth; oppositisepalous; alternating with the corolla members. Anthers cohering (occasionally), or connivent, or separate from one another; dehiscing via longitudinal slits (mostly), or dehiscing via pores (apically, e.g. Argostemma); introrse; tetrasporangiate; slightly appendaged (rarely?), or unappendaged. The anther appendages observed in Coprosma apical (by slight extension of the connective). Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate. Anther wall initially with one middle layer; of the ‘dicot’ type. Tapetum glandular. Pollen shed in aggregates (in the Gardenieae), or shed as single grains (mostly); when aggregated, in tetrads. Pollen grains aperturate, or nonaperturate (rarely); 3(–4) aperturate (mostly), or 4–12 aperturate; colpate (Paederieae, Galieae, Spermacoceae p.p.), or porate (Gardenieae), or colporate (polycolporate in Richardsonia), or foraminate; 2-celled, or 3-celled.

Gynoecium 2(–9) carpelled. Carpels usually reduced in number relative to the perianth. The pistil 1 celled (rarely), or 2(–9) celled. Gynoecium syncarpous; synovarious to eu-syncarpous; inferior (nearly always), or superior (only Gaertnera and Pagamea). Ovary 1 locular (rarely e.g. Gardenia), or 2(–9) locular. Gynoecium when bilocular (i.e. usually), transverse. Epigynous disk often present. Gynoecium stylate. Styles 1 (often simple), or 2(–5); free, or partially joined; attenuate from the ovary, or from a depression at the top of the ovary; apical; shorter than the ovary to much longer than the ovary. Stigmas wet type, or dry type; papillate, or non-papillate; Group II type and Group IV type. Placentation when unilocular, parietal; when two or more locular, axile. Ovules in the single cavity when unilocular, 6–100 (‘many’); 1–50 per locule (commonly one (Rubioideae), to ‘many’); pendulous, or horizontal, or ascending; anatropous, or hemianatropous; unitegmic; tenuinucellate. Endothelium not differentiated. Embryo-sac development Polygonum-type. Antipodal cells formed; 3; proliferating (occasionally), or not proliferating; ephemeral, or persistent. Endosperm formation nuclear. Embryogeny solanad.

Fruit fleshy, or non-fleshy; dehiscent, or indehiscent, or a schizocarp. Mericarps when schizocarpic 2(–9); comprising achenes, or comprising nutlets, or comprising drupelets (?). Fruit when non-schizocarpic a capsule, or a berry, or a drupe. Capsules septicidal, or loculicidal, or septicidal and loculicidal, or circumscissile (e.g. Mitratheca). Fruit 1–30 seeded. Seeds endospermic (usually), or non-endospermic (Guettardinae). Endosperm ruminate, or not ruminate; when present, oily. Seeds winged (rarely), or wingless. Cotyledons 2; flat (or rarely involute). Embryo achlorophyllous (8/11); straight (usually), or curved.

Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Cyanogenic, or not cyanogenic. Cynogenic constituents phenylalanine-derived (?). Alkaloids present (commonly), or absent. Iridoids detected; ‘Route I’ type (normal and seco), or ‘Route II’ type (b). Arthroquinones detected (21 genera); derived from shikimic acid (mostly), or polyacetate derived (Asperula). Proanthocyanidins present, or absent. Flavonols present (mostly), or absent; kaempferol and quercetin (mostly), or kaempferol, or quercetin. Ellagic acid absent (9 species, 9 gebera). Arbutin present. Ursolic acid present. Saponins/sapogenins present (occasionally), or absent. Aluminium accumulation demonstrated, or not found. Sugars transported as sucrose (in three genera). Inulin recorded (Cinchona, Gibbs 1974). C3 and CAM. C3 physiology recorded directly in Borreria, Coprosma, Crucianella, Galium, Richardia. CAM recorded directly in Hydnophytum, Myrmecodia. Anatomy non-C4 type (Cephalanthus, Crucianella, Diodia, Galium).

Geography, cytology. Frigid zone to tropical. Cosmopolitan. X = (6-)9/11(-17).

Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Gentianiflorae; Gentianales. Cronquist’s Subclass Asteridae; Rubiales. APG (1998) Eudicot; core Eudicot; Asterid; Euasterid I; Gentianales. Species 6000. Genera about 600; Acranthera, Acrobotrys, Acunaeanthus, Adinauclea, Agathisanthemum, Aidia, Aidiopsis, Airosperma, Aitchisonia, Alberta, Aleisanthia, Alibertia, Allaeophania, Alleizettella, Allenanthus, Alseis, Amaiouma, Amaracarpus, Amphiasma, Amphidasya, Ancylanthos, Anomanthodia, Antherostele, Anthorrhiza, Anthospermum, Antirhea, Aoranthe, Aphaenandra, Aphanocarpus, Appunettia, Appunia, Arctophyllum, Argocoffeopsis, Argostemma, Asemnantha, Asperula, Astiella, Atractocarpus, Atractogyne, Augusta, Aulacocalyx, Badusa, Balmea, Bataprine, Bathysa, Batopedina, Belonophora, Benkara, Benzonia, Berghesia, Bertiera, Bikkia, Blandibractea, Blepharidium, Bobea, Boholia, Borojoa, Bothriospora, Botryarrhena, Bouvardia, Brachytome, Bradea, Brenania, Breonadia, Burchellia, Burttdavya, Byrsophyllum, Caelospermum, Calanda, Callipeltis, Calochone, Calycophyllum, Calycosia, Calycosiphonia, Canephora, Canthium, Capirona, Captaincookia, Carpacoce, Carphalea, Carterella, Casasia, Catesbaea, Catunaregam, Cephaelis, Cephalodendron, Ceratopyxis, Ceriscoides, Ceuthocarpus, Chaetostachydium, Chalepophyllum, Chamaepentas, Chapelieria, Chassalia, Chazaliella, Chimarrhis, Chiococca, Chione, Chlorochorion, Chomelia, Choulettia, Chytropsia, Cigarilla, Cinchona, Cladoceras, Clarkella, Coccochondra, Coccocypselum, Coddia, Coelopyrena, Coffea, Coleactina, Colletoecima, Commitheca, Condaminea, Conostomium, Coprosma, Coptophyllum, Coptosapelta, Corynanthe, Coryphothamnus, Cosmibuena, Cosmocalyx, Coursiana, Coussarea, Coutaportla, Coutarea, Cowiea, Craterispermum, Cremaspora, Cremocarpon, Crobylanthe, Crocyllis, Crossopteryx, Crucianella, Cruciata, Cruckshanksia, Crusea, Cuatrecasasiodendron, Cubanola, Cuviera, Cyclophyllum, Damnacanthus, Danais, Deccania, Declieuxia, Dendrosipanea, Dentella, Deppea, Diacrodon, Dialypetalum, Dibrachyonostylus, Dichilanthe, Dictyandra, Didymaea, Didymochlamys, Didymopogon, Didymosalpynx, Diodella, Diodia, Dioecrescis, Dioicodendron, Diplospora, Discospermum, Diyaminauclea, Dolichodelphys, Dolicholobium, Dolichometra, Dolicera, Duidania, Dunnia, Duperrea, Duroia, Durringtonia, Ecpoma, Eizia, Elaeagia, Eleutheranthus, Emmenopterys, Emmeorhiza, Eosanthe, Eriosemopsis, Erithalis, Ernodea, Etericius, Euclinia, Exallage, Exostema, Fadogia, Fadogiella, Fagerlindia, Faramea, Ferdinandusa, Feretia, Fergusonia, Fernelia, Flagenium, Flexanthera, Gaertnera, Gaillonia, Galiniera, Galium, Gallienia, Galopina, Gamotopea, Gardenia, Gardeniopsis, Genipa, Gentingia, Geophila, Gillespiea, Gleasonia, Glionnetia, Glossostipula, Gomphocalyx, Gonzalagunia, Gouldia, Greenea, Greeniopsis, Guettarda, Gynochtodes, Gyrostipula, Habroneuron, Haldina, Hallea, Hamelia, Hyataella, Hedstromia, Hedyotis, Hedythyrsus, Heinsenia, Heinsia, Hekistocarpa, Heterophyllaea, Hillia, Himalrandia, Hindsia, Hintonia, Hippotis, Hitoa, Hodgkinsonia, Hoffmannia, Holstianthus, Homollea, Homolliella, Houstonia, Hutchinsonia, Hydnophytum, Hydrophylax, Hymenocnemis, Hymenocoleus, Hymenodictyon, Hyperacanthus, Hypobathrum, Hyptianthera, Ibetralia, Indopolysolenia, Isertia, Isidorea, Ixora, Jackiopsis, Janotia, Jaubertia, Joosia, Jovetia, Kailarsenia, Kajewskiella, Keenania, Keetlia, Kelloggia, Kerianthera, Khasiaclunea, Klossia, Knoxia, Kochummenia, Kohautia, Kraussia, Kutchubaea, Ladenbergia, Lagynias, Lamprothamnus, Lasianthus, Lathraeocarpa, Lecananthus, Lecanosperma, Lecariocalyx, Lelya, Lemyrea, Lepidostoma, Leptactina, Leptodermis, Leptomischus, Leptoscela, Leptostigma, Lerchea, Leucocodon, Leucolophus, Limnosipanea, Lindenia, Litosanthes, Lucinaea, Luculia, Lucya, Ludekia, Macbrideina, Machaonia, Macrocnemum, Macrosphyra, Maguireocharis, Maguireothamnus, Malanea, Manettia, Manostachya, Mantalania, Margaritopsis, Maschalocorymbus, Maschalodesme, Massularia, Mastixiodendron, Mazaea, Melanopsidium, Mericarpaea, Merumea, Metadina, Meyna, Micrasepalum, Microphysa, Mitchella, Mitracarpus, Mitrasacmopsis, Mitriostigma, Molopanthera, Monosalpinx, Montamans, Morelia, Morierina, Morinda, Morindopsis, Motleyia, Mouretia, Multidentia, Mussaenda, Mussaendopsis, Mycetia, Myonima, Myrmecodia, Mymeconauclea, Myrmephytum, Naletonia, Nargedia, Neanotis, Neblinathamnus, Nematostylis, Nenax, Neobertiera, Neoblakea, Neobreonia, Neofranciella, Neohymenopogon, Neolamarckia, Neolaugeria, Neopentanisia, Nernstia, Nertera, Nesohedyotis, Neurocalyx, Nichallea, Nodocarpaea, Nonatelia, Normandia, Nostolachma, Ochreinauclea, Octotropis, Oldenlandia, Oldenlandiopsis, Oligocodon, Omiltemia, Opercularia, Ophiorrhiza, Ophriococcus, Oregandra, Oreopolus, Osa, Otiophora, Otocalyx, Otomeria, Ottoschmidtia, Oxyanthus, Pachystigma, Pachystylus, Paederia, Pagamea, Pagameopsis, Palicourea, Pamplethantha, Paracephaelis, Parachimarrhis, Paracorynanthe, Paragenipa, Paraknoxia, Parapentas, Paratriaina, Pauridiantha, Pausinystalia, Pavetta, Payera, Pelagodendron, Pentagonia, Pentaloncha, Pentanisia, Pentanopsis, Pentas, Pentodon, Peponidium, Perakanthus, Perama, Peratanthe, Peripeplus, Pertusadina, Petagomoa, Petitiocodon, Phellocalyx, Phialanthus, Phitopis, Phuopsis, Phyllacanthus, Phyllis, Phyllocrater, Phyllomelia, Phyllohydrax, Picardaea, Pimentelia, Pinariphyllon, Pinckneya, Pittoniotis, Placocarpa, Placopoda, Plectronia, Plectoniella, Pleiocarpidia, Pleiocoryne, Pleiocraterium, Plocama, Poecilocalyx, Pogonolobus, Pogonopus, Polysphaeria, Polyura, Pomax, Porterandia, Portlandia, Posoqueria, Pouchetia, Praravinia, Pravinaria, Preussiodora, Prismatomeris, Proscephaleium, Psathura, Pseudaidia, Pseudogaillonia, Pseudogardenia, Pseudohamelia, Pseudomantalania, Pseudomussaenda, Pseudonesohedyotis, Pseudopyxis, Pseudosabicea, Psilanthus, Psychotria, Psydrax, Psyllocarpus, Pteridocalyx, Pterogaillonia, Pubistylus, Putoria, Pygmaeothamnus, Pyragra, Pyrostria, Rachicallis, Ramosmania, Randia, Raritebe, Readea, Remijia, Rennellia, Retiniphyllum, Rhadinopus, Raphidura, Rhipidantha, Rhopalobrachium, Rhyssocarpus, Richardia, Riqueuria, Robynsia, Roigella, Ronabea, Rondeletia, Rothmannia, Rubia, Rudgea, Rustia, Rutidea, Rytigynia, Sabicea, Sacosperma, Saldinia, Salzmannia, Saprosma, Sarcopygme, Schachtia, Schismatoclada, Schizenterospermum, Schizocalyx, Schizocolea, Schizomussaenda, Schizostigma, Schmidtottia, Schradera, Schumanniophyton, Schwendenera, Scolosanthus, Scyphiphora, Scyphochlamys, Scyphostachys, Sericanthe, Serissa, Shaferocharis, Sherardia, Sherbournia, Siderobombyx, Siemensia, Simira, Sinoadina, Sipanea, Sipaneopsis, Siphonandrium, Sommera, Spathichlamys, Spermacoce, Spermadictyon, Sphinctanthus, Spiradiclis, Squamellaria, Stachyarrhena, Stachyococcus, Staelia, Standleya, Steenisia, Stelechantha, Stephanococcus, Stevensia, Steyermarkia, Stichianthus, Stilpnophyllum, Stipularia, Stomandra, Streblosa, Streblosiopsis, Strempelia, Striolaria, Strumpfia, Stylosiphonia, Suberanthus, Sukunia, Sulitia, Synaptantha, Syringantha, Tamilnadia, Tammsia, Tapiphyllum, Terenna, Tarennoidea, Temnocalyx, Temnopteryx, Tennantia, Thecorchus, Thogsennia, Thyridocalyx, Timonius, Tobagoa, Tocoyena, Tortuella, Trailliaedoxa, Tresanthera, Triainolepis, Tricalysia, Trichostachys, Trigonopyren, Trukia, Tsiangia, Uragoga, Urophyllum, Valantia, Vangueria, Vangueriella, Vangueriopsis, Versteegia, Villaria, Virectaria, Warburgina, Warszewiczia, Wendlandia, Wernhamia, Wiasemskya, Wittmackanthus, Xanthophytum, Xantonnea, Xerococcus, Yutajea, Zuccarinia.

For a recent assessment of the subfamilial classification, see Bremer’s (1996) analyses of morphological and molecular data.

Economic uses, etc. Sources of coffee (Coffea), quinine (Cinchona, ipecac (Cephaelis), and many ornamentals (e.g. Gardenia, Rubia, Mitchella, Coprosma).

Illustrations. • temperate herbs (Asperula, Galium, Rubia, Sherardia). • Woody genera (Bouvardia, Rondeletia, Lindenia, Ixora). • Sub-shrubs (Hindsia). • Manettia (climber), Myrmecodia (myrmecophilous epiphyte), Hillia. • Technical details (Rubia, Galium, Coffea). • Technical details (Coffea). • Technical details (Pavetta). • Technical details (Leptodermis, Bouvardia, Cinchona, Coprosma, Luculia).


Cite this publication as: ‘L. Watson and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000. http://biodiversity.uno.edu/delta/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Watson and Dallwitz (1991) should also be cited (see References).

Index