Rubiaceae Juss.

Rubiaceae, B. Verdcourt. Flora Zambesiaca 5:1. 1989

Morphology General Habit

Small to large trees, shrubs or less often annual or perennial herbs or woody or herbaceous climbers, sometimes spiny; tissues in many tribes containing abundant rhaphides Small to large trees, shrubs (including suffrutices from woody rootstocks) or less often annual or perennial herbs or woody or herbaceous climbers, sometimes spiny; raphides (tab. 1/7) present or absent; crystal sand absent or present (these two mutually exclusive) Small to large trees, shrubs (including suffrutices from woody rootstocks) or less often annual or perennial herbs or woody or herbaceous climbers, sometimes spiny; raphides (tab. 1/7) present or absent; crystal sand absent or present (these two mutually exclusive)

Morphology Leaves

Leaves opposite or verticillate, decussate, almost always entire, very rarely (not in Africa) palmatifid, toothed or finely denticulate, always obviously stipulate (save in some Rubieae, where the stipules may be considered foliar or almost absent according to interpretation), the stipules interpetiolar or intrapetiolar, entire or, particularly in herbaceous genera, variously divided into lobes or fimbriae, often tipped or separated by mucilaginous hairs known as colleters and often with colleters inside the base; the leaves in certain tribes sometimes contain small bacterial nodules Leaves opposite or occasionally verticillate, decussate, almost always entire, very rarely sparsely toothed or lobed (not in the Flora Zambesiaca area), always obviously stipulate (save in some Rubieae, where the stipules may be considered leaf-like or almost absent according to interpretation); domatia (mite associated pits or tufts of hairs) very often present axils of lateral nerves on the leaf lower surface; bacterial nodules present in a few genera Leaves opposite or occasionally verticillate, decussate, almost always entire, very rarely sparsely toothed or lobed (not in the Flora Zambesiaca area), always obviously stipulate (save in some Rubieae, where the stipules may be considered leaf-like or almost absent according to interpretation); domatia (mite associated pits or tufts of hairs) very often present axils of lateral nerves on the leaf lower surface; bacterial nodules present in a few genera

Morphology Reproductive morphology Flowers

Flowers rarely solitary, mostly in various terminal or axillary inflorescences, all basically cymose but variously aggregated into panicles, etc., occasionally in globose heads to an extent that the ovaries are adnate; bracts vestigial to well developed, even conspicuous; flowers usually hermaphrodite, rarely unisexual, regular or nearly so (except in Posoqueria (America)) or corolla tube rarely curved, homostylous or quite often heterostylous with 2 or rarely 3 forms (long-styled (dolichostylous), short-styled (brachystylous) or equal-styled (isostylous)) Flowers regular or slightly to distinctly (not in Africa) zygomorphic, hermaphrodite or less often unisexual, homostylous, in which case very often protandrous, with or without pollen presentation (tab. 73/F,G), or rarely protogynous (not in Africa), or heterostylous with 2 or less often 3 forms (long-styled (dolichostylous), short-styled (brachystylous) or equal-styled (isostylous) (tab. 73/E) Flowers regular or slightly to distinctly (not in Africa) zygomorphic, hermaphrodite or less often unisexual, homostylous, in which case very often protandrous, with or without pollen presentation (tab. 73/F,G), or rarely protogynous (not in Africa), or heterostylous with 2 or less often 3 forms (long-styled (dolichostylous), short-styled (brachystylous) or equal-styled (isostylous) (tab. 73/E)

Morphology Leaves Stipules

Stipules interpetiolar or occasionally intrapetiolar (mostly New World taxa); lobes shortly fused above the petioles and sometimes forming a sheath, or lobes free, entire, bifid or rarely laciniate, or particularly in herbaceous genera, fimbriate, often tipped with or separated by colleters (mucilaginous glands) (tab. 74), often with colleters inside the limb, especially towards the base Stipules interpetiolar or occasionally intrapetiolar (mostly New World taxa); lobes shortly fused above the petioles and sometimes forming a sheath, or lobes free, entire, bifid or rarely laciniate, or particularly in herbaceous genera, fimbriate, often tipped with or separated by colleters (mucilaginous glands) (tab. 74), often with colleters inside the limb, especially towards the base

Morphology Reproductive morphology Inflorescences

Inflorescences terminal or axillary, basically thyrsoid, variously aggregated into panicles etc., occasionally in globose heads sometimes to an extent that the ovaries are adnate, or sometimes flowers solitary; bracts vestigial to well developed, even conspicuous Inflorescences terminal or axillary, basically thyrsoid, variously aggregated into panicles etc., occasionally in globose heads sometimes to an extent that the ovaries are adnate, or sometimes flowers solitary; bracts vestigial to well developed, even conspicuous

Morphology Reproductive morphology Flowers Calyx

Calyx gamosepalous, the tube (i.e. calyx tube**) mostly adnate to the ovary, the limb with tubular part (i.e. limb-tube) present or absent, truncate or bearing minute teeth to well developed lobes (tab. 73/A1–A4), valvate (often separated by sinuses), or less often imbricate or contorted in aestivation, in a few genera 1–several lobes sometimes slightly to considerably enlarged to form a leaf-like often coloured blade (calycophyll) (tab. 73/A5) Calyx gamosepalous, the tube mostly adnate to the ovary, (3)4–5(8)-toothed or lobed, sometimes only minutely so, with open, valvate, imbricate or contorted aestivation, 1 or several lobes sometimes slightly to very considerably enlarged to form a leafy often coloured lamina Calyx gamosepalous, the tube (i.e. calyx tube**) mostly adnate to the ovary, the limb with tubular part (i.e. limb-tube) present or absent, truncate or bearing minute teeth to well developed lobes (tab. 73/A1–A4), valvate (often separated by sinuses), or less often imbricate or contorted in aestivation, in a few genera 1–several lobes sometimes slightly to considerably enlarged to form a leaf-like often coloured blade (calycophyll) (tab. 73/A5)

Morphology Reproductive morphology Flowers Corolla

Corolla predominantly white but sometimes coloured, small to large and showy, gamopetalous, mostly salver- shaped to funnel-shaped or less often campanulate, occasionally tube very short, the tube rarely curved, (3)4–5(11)-lobed, the lobes contorted (mostly to the left, infrequently to the right) or valvate (sometimes induplicate or reduplicate), with or without a contact zone (i.e. thickened margin), less often imbricate (tab. 73/B–D) Corolla small to large and showy, gamopetalous, rotate to salver-shaped or funnel-shaped, the tube often very long, (3)4–5(11)-lobed, the lobes mostly contorted or valvate, sometimes valvate-induplicate, rarely imbricate or quincuncial Corolla predominantly white but sometimes coloured, small to large and showy, gamopetalous, mostly salver- shaped to funnel-shaped or less often campanulate, occasionally tube very short, the tube rarely curved, (3)4–5(11)-lobed, the lobes contorted (mostly to the left, infrequently to the right) or valvate (sometimes induplicate or reduplicate), with or without a contact zone (i.e. thickened margin), less often imbricate (tab. 73/B–D)

Morphology Reproductive morphology Flowers Androecium

Pollen various, mostly simple, isopolar and 3- colporate, but sometimes porate, the number of colpi or pores varying from 2 to 25, globose, ovoid or discoid, sometimes (in some Gardenieae) in tetrads or rarely in polyads Stamens usually as many as the corolla lobes and alternate with them, epipetalous or not (some New World tribes only); anthers basi- or more often dorsifixed, introrse rarely porate (not in the Flora Zambesiaca area), the thecae rarely transversely multilocellate Stamens usually as many as the corolla lobes and alternate with them, epipetalous or not (some New World tribes only); anthers basi- or more often dorsifixed, introrse rarely porate (not in the Flora Zambesiaca area), the thecae rarely transversely multilocellate Pollen various, mostly simple, isopolar and 3- colporate, but sometimes porate, the number of colpi or pores varying from 2 to 25, globose, ovoid or discoid, sometimes (in some Gardenieae) in tetrads or rarely in polyads Stamens usually as many as the corolla-lobes and alternate with them, epipetalous; anthers basi-or dorsifixed, introrse, the thecae rarely multilocellate transversely Pollen various, mostly simple, isopolar and 3-colporate, but sometimes porate, the number of colpi or pores varying from 2–25, globose, ovoid or discoid, sometimes (in some Gardenieae) in tetrads or rarely polyads

Morphology Reproductive morphology Flowers Nectaries

Disk usually functioning as a nectary, positioned above the ovary inside the base of the calyx limb, annular to cushion-shaped or tubular, sometimes 2-lobed, occasionally fused to base of calyx limb-tube (Naucleeae) or absent (in wind-pollinated flowers) Disk usually functioning as a nectary, positioned above the ovary inside the base of the calyx limb, annular to cushion-shaped or tubular, sometimes 2-lobed, occasionally fused to base of calyx limb-tube (Naucleeae) or absent (in wind-pollinated flowers) Disc often present, 2-lobed or tubular

Morphology Reproductive morphology Flowers Gynoecium

Ovary inferior, rarely half-inferior or superior (in Gaertnera), syncarpous of 2–10(12 or more) carpels, but predominantly of 2, and therefore predominantly 2-locular, but 3–10(12) (in Urophylleae can appear higher than actual carpel number due to supplementary incomplete partitions), or infrequently uni-locular (or partly so); ovules l–numerous per locule; placentation axile (attached to septum at apex, middle or base, usually on a placenta, often embedded in fleshy placentas) or infrequently (in some Gardenieae) parietal; ovules anatropous; style simple, usually long (but very short in Rubieae) and narrow, at the top either cylindrical, clavate, or otherwise modified to form a pollen presenter (the actual stigmatic surface sometimes confined to specific areas, eg the inner faces of the lobes**), or divided into 2–many (according to number of carpels) linear, spathulate or clavate stigmatic lobes Ovary inferior, rarely half-inferior or superior (in Gaertnera), syncarpous of 2–10(12 or more) carpels, but predominantly of 2, and therefore predominantly 2-locular, but 3–10(12) (in Urophylleae can appear higher than actual carpel number due to supplementary incomplete partitions), or infrequently uni-locular (or partly so); ovules l–numerous per locule; placentation axile (attached to septum at apex, middle or base, usually on a placenta, often embedded in fleshy placentas) or infrequently (in some Gardenieae) parietal; ovules anatropous; style simple, usually long (but very short in Rubieae) and narrow, at the top either cylindrical, clavate, or otherwise modified to form a pollen presenter (the actual stigmatic surface sometimes confined to specific areas, eg the inner faces of the lobes**), or divided into 2–many (according to number of carpels) linear, spathulate or clavate stigmatic lobes Ovary inferior, rarely half-inferior or (in Gaertnera) superior, syncarpous of 2–5 or more carpels, but predominantly of 2 and therefore predominantly 2-locular, but 3–5 or even 12 or more (eg in Urophylleae due to supplementary incomplete partitions); placentation axile or (in some Gardenieae) parietal; ovules 1-many per locule, often embedded in fleshy placentas, erect, basal or horizontal, anatropous; style simple, usually long and narrow, the “stigma” either cylindrical, clavate, or otherwise modified to form a “receptaculum pollinis” or divided into 2-many linear, spathulate or clavate lobes, the actual stigmatic surface sometimes confined to certain areas, eg the inner faces of the lobes

Morphology Reproductive morphology Fruits

Fruit small to very large, 2–many-seeded, dehiscent (capsules either loculicidal, septicidal, opening by a beak or infrequently circumscissile, or splitting into mericarps), or indehiscent (berries, including forms with woody walls, or drupes), occasionally (eg in Nauclea and Morinda) united to form syncarps; if drupes containing one-seeded pyrenes thin- or thick-walled, opening by pre-formed germination slits or not, or less often a multi-seeded stone Fruit small to very large, 2–many-seeded, dehiscent (capsules either loculicidal, septicidal, opening by a beak or infrequently circumscissile, or splitting into mericarps), or indehiscent (berries, including forms with woody walls, or drupes), occasionally (eg in Nauclea and Morinda) united to form syncarps; if drupes containing one-seeded pyrenes thin- or thick-walled, opening by pre-formed germination slits or not, or less often a multi-seeded stone Fruit small to quite large (0|2–20 cm.), a capsule, berry or drupe or indehiscent or woody, occasionally (eg in Naulea and Morinda) united to form syncarps, (1)2-many-seeded, if capsules then loculicidal or septicidal or opening by a beak

Morphology Reproductive morphology Seeds

Seeds small to rather large, sometimes winged; testa cells in some tribes with very distinct pits; endosperm present (save in Guettardeae), entire or ruminate; embryo straight or rarely curved; radicle erect or horizontal, mostly longer than the cotyledons, orientation pendulous Seeds small to rather large, sometimes winged; testa cells in some tribes with very distinct pits; endosperm present (save in Guettardeae), entire or ruminate; embryo straight or rarely curved; radicle erect or horizontal, mostly longer than the cotyledons, orientation pendulous Seeds small to rather large, sometimes winged; testa cells in some tribes with very distinct pits; albumen present (save in Guettardeae); embryo straight or rarely curved, the radicle mostly longer than the cotyledons

Rubiaceae, F.N. Hepper & R.W.J. Keay. Flora of West Tropical Africa 2. 1963

Morphology General Habit

Trees, shrubs or rarely herbs

Morphology Leaves

Leaves opposite or rarely verticillate, entire; stipules inter- or intra-petiolar, often connate, rarely leafy and not distinguishable from the leaves

Morphology Reproductive morphology Flowers

Flowers usually hermaphrodite, actinomorphic or very rarely slightly zygomorphic, solitary to capitate

Morphology Reproductive morphology Flowers Calyx

Calyx adnate to the ovary

Morphology Reproductive morphology Flowers Corolla

Corolla epigynous, more or less tubular, rarely campanulate; lobes 4-12, contorted, imbricate or valvate

Morphology Reproductive morphology Flowers Androecium

Stamens epipetalous, as many as and alternate with the corolla-lobes; anthers mostly separate, 2-celled, opening lengthwise or rarely by terminal pores, rarely transversely septate

Morphology Reproductive morphology Flowers Gynoecium

Ovary inferior or rarely superior, 2- or more-celled, with axile, apical or basal placentas, or rarely 1-celled with parietal placentas; style often slender; ovules 1 to many

Morphology Reproductive morphology Fruits

Fruit a capsule, berry or drupe

Morphology Reproductive morphology Seeds

Seeds rarely winged, mostly with endosperm, the latter rarely ruminate; embryo straight or curved

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution

The Rubiaceae is a large family of c. 614 genera containing c. 13,150 species. The family has a cosmopolitan distribution with the greatest number of species occurring in the tropics. There are 74 genera (including climbing, woody and herbaceous taxa) represented in the New Guinea and the Solomon Islands with a total of c. 780 species, including many endemics.

Ecology

The Rubiaceae are distributed in a wide variety of habitats and at most elevations.

Recognition

They can be recognised by the simple, opposite leaves with entire margins, interpetiolar stipules, an inferior ovary (rarely semi-superior), tubular corolla, and an equal number of alternating stamens and corolla lobes. They may be confused with Myrtaceae (gland dots, many stamens, no interpetiolar stipules), Apocynaceae (superior ovary, sap, lack of definite interpetiolar stipules), Loganiaceae (superior ovary, no interpetiolar stipules), Clusiaceae (superior ovary, sap, no interpetiolar stipules) and Rhizophoraceae (unequal stamen and corolla lobe number,  sometimes superior ovary and/or toothed leaf margin). Ixora L., Psychotria L. and Timonius Rumph. ex DC. are the most species rich arborescent genera in New Guinea.

Morphology General Habit

Trees, shrubs, climbers or herbs, sometimes epiphytic. Thorns or hooks sometimes present

Morphology General

Calcium-oxalate crystals (e.g. raphides) sometimes present Trichomes usually unicellular and unbranched

Morphology Leaves Stipules

Stipules present, interpetiolar, caducous or persistent, varying in shape and size

Morphology General Colleters

Colleters often present between stem and stipule

Morphology Leaves

Leaves simple, opposite, rarely whorled, margins entire, venation pinnate, domatia often present in axils of secondary veins

Morphology Reproductive morphology Inflorescences

Inflorescences terminal, axillary, pseudo-axillary, cauliflorous or ramiflorous, thyrsoid, capituliform, spike-like or congested into globular heads; bracts often present

Morphology Reproductive morphology Flowers

Flowers (2–)4–5(–12)-merous, bisexual or unisexual, aestivation contorted, imbricate or valvate; calyx tubular, sometimes reduced, lobes distinct or absent, occasionally 1 or more enlarged; corolla tubular, corolla lobes distinct, often white or cream; stamens as many as and alternating with corolla lobes, filaments adnate to the corolla in a single whorl; anthers dehiscing by longitudinal slits (rarely by apical pores); ovary inferior, (rarely semi-superior), carpels (1–)2–5(–many), syncarpous or free; styles united (rarely free to base) stigmatic lobes equal to number of carpels, free or fused; disk present (rarely absent); ovules 1–many. Fruits usually red, yellow, orange, white, blue or black, fleshy or dry, dehiscent or indehiscent, drupaceous or not, syncarpous or free

Morphology Reproductive morphology Seeds

Seeds 1–many, size and shape variable.

Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://creativecommons.org/licenses/by/3.0

Morphology General Habit

Herbs, climbers, lianas, shrubs, trees, usually understorey shrubs

Morphology Leaves

Leaves opposite, sometimes whorled, entire, linked by interpetiolar (sometimes intrapetiolar) stipules of varied shapes and sizes, with colleters within

Morphology Reproductive morphology Inflorescences

Inflorescences variable, panicles, cymes, racemes, fascicles, terminal or axillary, sometimes flowers solitary, bracts often present, sometimes corolline or involucral

Morphology Reproductive morphology Flowers

Flowers 4-5(-6-12) merous, hermaphrodite or bisexual, often heterostylic or with secondary pollen presentation (when bisexual); calyx fused with hypanthium, free part tubular or lobed, sometimes very short, in some genera one calyx -lobe developed as a semaphyll; corolla gamopetalous, aestivation valvate, imbricate, contorted, mostly radial (rarely zygomorphic), small to 15(-30) cm long, white, cream, yellow, pink, blue, red, violet or mauve, sometimes bi-coloured, glabrous to hairy outside or within, stamens alternate to the corolla -lobes, stigma undivided to more commonly 2- lobed

Morphology Reproductive morphology Fruits

Fruits capsular, berry -like or drupaceous with 1-many pyrenes; seeds 1-numerous, rounded, angled or winged .

Diagnostic

Borreria (= Spermacoce) G. Mey.: herbs to subshrubs, stipules fringed, flowers tetramerous, 2-seeded capsules. Cinchona L.: trees, corolla long, pinkish, many ovules per locule, seeds winged in capsules. Faramea Aubl.: shrubs to trees, stipules aristate or triangular, flowers blue, fruits 1-seeded. Genipa L.: trees, pre-floration contorted, flowers bisexual, secondary pollen presentation, large berries with fleshy pulp. Manettia Mutis ex L.: twining climber with showy flowers, many-seeded capsular fruit. Palicourea Aubl.: shrubs to treelets, bilobed to bifid stipules, flowers colourful, corolla tube gibbose, fruits 2-5-seeded, fleshy. Psychotria L.: shrubby to tree-like, bilobed or rounded stipules, corolla tube straight, flowers small, white, cream or yellow, fruits 2-5-seeded, fleshy. Rudgea Salisb.: shrubs to trees, stipules fringed to appendiculate, corolla tube straight, often longer than Psychotria. Key differences from similar families: Inferior ovary sets apart from Loganiaceae and Gentianaceae. Corolla generally radial separates from Campanulaceae, Acanthaceae and Lamiales. Number of locules. Ovules per locule. Type of fruit. Presence of pyrenes. Aestivation. Habit would help to place the specimen within a subfamily or tribe. Distinguishing characters (always present): Simple, opposite (rarely whorled) leaves with entire margin. Interpetiolar and sometimes intrapetiolar stipules. Corolla gamopetalous (exc. Dichapetalanthus). Ovary inferior (exc. Pagamea Aubl.). Colleters in the inside of stipules and calyx. Secondary pollen presentation in Gardenieae. Herbs with varied capsular fruits in Spermacoceae. Pyrenes and raphids in some groups.

Distribution

Exotic species of Ixora L. from China Several species and cultivars of Mussaenda L., Gardeniajasminoides Ellis and Pentaslanceolata Schum. are widely cultivated ornamental plants in the Neotropics. Species of cultivated Coffea L. commonly escape into forests near farms in Brazil. Species of Cinchona L. cultivated for quinine have been introduced in many tropical countries. Genipaamericana L. is cultivated throughout South America for edible fruits and dye. Weedy genera such as Galium L., Borreria G.Mey., Diodia L., Richardia L.and Mitracarpus Zucc. have distribution sometimes worldwide. Endemic genera in the Caribbean are often monotypic. Throughout the Neotropics, 3rd to 5th family in number of species in tropical forests.

Note

One of the most important plant families from the Neotropics, it occupies between 3rd and 5th place in species richness in tropical forests. Number of genera: 637 genera and over 10,000 species worldwide, of which approximately 220 genera and 4,500 species are Neotropical. Notes on delimitation: Includes Dialypetalanthus Kuhlm. (formerly Dialypetalanthaceae).

Gemma Bramley, Anna Trias-Blasi & Richard Wilford (2023). The Kew Temperate Plant Families Identification Handbook. Kew Publishing Royal Botanic Gardens, Kew

Recognition

Characters of similar families: Myrtaceae: leaves with pellucid (clear) gland dots, interpetiolar stipules lacking, flowers usually with many anthers. Apocynaceae: abundant white exudate present, interpetiolar stipules usually lacking, ovary superior. Oleaceae: interpetiolar stipules lacking, stamens 2 (rarely 4), ovary superior.

Morphology General Habit

Trees, shrubs, woody or herbaceous climbers, annual or perennial herbs, rarely epiphytes or aquatics, sometimes with thorns or hooks, stems square or terete

Morphology General Raphide

Raphides sometimes present

Morphology Leaves Stipules

Stipules interpetiolar rarely intrapetiolar, undivided, bifid or multi-lobed, or stipules leaf-like; colleters often on stipules or calyces

Morphology Leaves

Leaves simple, never compound; opposite decussate, distichous, or whorled; sometimes anisophyllous; margins entire or rarely with hooks or lobes, sometimes domatia present, sometimes bacterial nodules present

Morphology Reproductive morphology Inflorescences

Inflorescences axillary or terminal, often on reduced shoots, thyrsoid, highly variable or flowers solitary

Morphology Reproductive morphology Flowers

Flowers bisexual, or unisexual, often heterostylous, or with secondary pollen presentation, sometimes wind pollinated; commonly 4–5-merous, actinomorphic; calyx, corolla lobes and stamens usually equal in number, calyx lobes sometimes uneven to few enlarged, stamens alternipetalous; ovary inferior, rarely superior, (1)2– (many)-locular, placentation axile, sometimes parietal, or rarely both; style simple, entire or bilobed or as a pollen presenter

Morphology Reproductive morphology Fruits

Fruit indehiscent fleshy, or leathery or woody berries or drupes, or dehiscent capsules or mericarps, sometimes fused

Morphology Reproductive morphology Seeds

Seeds variable, (1)2–many, rarely winged or with elaiosomes; endosperm present, rarely absent.

Distribution

A cosmopolitan family of ca. 600 genera and ca.14,000 species. The mainly herbaceous tribe Rubieae is the predominant tribe in Temperate regions. Galium is the largest temperate genus in terms of number of species and it also has the most widespread distribution.

Note

Stipules interpetiolar. Leaves opposite simple, entire. Flowers actinomorphic, corolla tubular; stamens epipetalous, alternipetalous, number equalling the corolla lobes; ovary inferior.

Description Author

Sally Dawson

Timothy Utteridge & Gemma Bramley (2020). The Kew Tropical Plant Families Identification Handbook, Second Edition. Kew Publishing Royal Botanic Gardens, Kew

Note

Leaves opposite, simple, entire; stipules interpetiolar. Flowers actinomorphic; corolla tubular; stamens fixed to the corolla tube, the same number as the corolla lobes; ovary inferior.

Recognition

Characters of similar families: Apocynaceae: white exudate present and ‘bleeding’ from cut surfaces; interpetiolar stipules usually lacking; ovary superior. Myrtaceae: leaves with pellucid (clear) gland dots; (interpetiolar) stipules lacking; flowers usually with many anthers. Oleaceae: (interpetiolar) stipules lacking; petals 4, anthers 2, ovary superior. Rhizophoraceae: leaf margins sometimes toothed/ serrate; petals free, stamens more numerous than petals (e.g. petals 4–5; stamens 8–10). Acanthaceae: leaf margins often serrate, dentate or lobed; corolla zygomorphic, ovary superior.

Morphology General Habit

Trees, shrubs, woody climbers, epiphytes, or aquatics

Morphology Leaves Stipules

Stipules interpetiolar, rarely intrapetiolar, or stipules exactly leaf-like; colleters (hair-like, exudate secreting glands) frequently present on the stipule and calyx

Morphology Leaves

Leaves opposite (decussate or arranged in the same plane, or whorled; simple (very rarely lobed), never compound; margins entire

Morphology Reproductive morphology Inflorescences

Inflorescences axillary or terminal, often on reduced shoots, basically thyrsoid, but highly variable, or flowers solitary

Morphology Reproductive morphology Flowers

Flowers bisexual, less often unisexual, often heterostylous, or with secondary pollen presentation, or more rarely wind pollinated; commonly 4- or 5-merous, actinomorphic; calyx and corolla usually with the same number of lobes; stamens the same number as corolla lobes; ovary inferior, rarely superior 1–many-locular, commonly 2-locular, placentation frequently axile, but also parietal, less often mixed axile and parietal; style simple (entire or 2-lobed), or complex and fused into a stylar head (for secondary pollen presentation)

Morphology Reproductive morphology Fruits

Fruit small or quite large, indehiscent (fleshy but sometimes leathery or woody, berries or drupes with usually 2 or more 1-seeded pyrenes, less frequently a multi-seeded stone) or dehiscent (capsules, mericarps), sometimes fused (syncarpic)

Morphology Reproductive morphology Seeds

Seeds small or quite large, sometimes winged; endosperm present, rarely absent.

Distribution

13,200 species in c. 600 genera; species-rich in both Old and New World tropics. Psychotria is common throughout the tropics and comprises c. 2,000 species.

Description Author

Aaron Davis

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Herbs, shrubs or trees; leaves opposite or whorled, simple and entire or rarely toothed; stipules often sheathing the stem, sometimes divided into linear segments or reduced to glandular hairs, sometimes expanded and leaf-like

Morphology Reproductive morphology Flowers

Flowers regular, usually perfect, solitary or in cymes or panicles, sometimes condensed to heads or glomerules, or rarely in spikes, with or without bracts

Morphology Reproductive morphology Flowers Calyx

Calyx of 4–6 free or united sepals, or rarely the limb truncate

Morphology Reproductive morphology Flowers Corolla

Corolla gamopetalous, mostly 4–6-lobed (rarely more), the lobes valvate, imbricate or twisted

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens as many as the corolla-lobes and alternate with them, inserted in the corolla-tube; anthers 2-celled, opening lengthwise

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary mostly inferior, crowned by a disc, usually 2-celled, the placentation various, rarely 1- or several-celled; ovules 1–many in each cavity; style usually slender, often forked toward the apex

Note

Heterostyly is present in many genera

Morphology Reproductive morphology Fruits

Fruit a capsule, berry, drupe or schizocarp; seeds usually with plentiful endosperm.

Distribution

A very large cosmopolitan family of more than 450 genera and about 6,000 species, most numerous in the tropics.