Myrtaceae Juss.

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

Distribution

A family of about 120 genera and approximately 5000 species, well-circumscribed molecularly and morphologically. Found throughout the Neotropics, sub-Saharan Africa, tropical and subtropical Asia to Australasia and the Pacific, one species in the Mediterranean; in New Guinea there are 29 arborescent genera with c. 340 tree species.

Recognition

The family has peeling or fibrous bark, simple, exstipulate leaves with entire margins, opposite or alternately arranged and usually with a distinct marginal vein running along the length of the leaf, pellucid dots giving an aromatic (±camphor-like) smell when crushed; the flowers have many stamens with an inferior to semi-inferior; fruits mostly fleshy in the tropics but several representatives have dehiscent fruits.

Morphology General Habit

Trees and shrubs, often with flaky or fibrous bark, usually evergreen

Morphology General Indumentum

Hairs simple if present

Morphology Leaves Stipules

Stipules absent or very rudimentary

Morphology Leaves

Leaves simple, opposite, alternate or spiral, petiolate, with entire margins, venation various but intramarginal vein often present, aromatic, with pellucid gland dots, often aromatic if crushed

Morphology Reproductive morphology Flowers

Flowers 4–5 (rarely 8)-merous, bisexual, epigynous, hypanthium usually present; calyx lobes free or fused into a calyptra, when abscission is circumscissile; petals if present are usually free and imbricate in bud; stamens usually many with slender filaments, filaments free or fused into bundles, anthers usually bilocular and opening by longitudinal slits; ovary inferior or semi-inferior (rarely superior), placentation usually axile but occasionally parietal, style single, simple. Fruit a capsule, berry or drupe

Morphology Reproductive morphology Seeds

Seeds 1 to many.

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

Trees or woody shrubs; hairs simple or occasionally dibrachiate

Morphology Leaves

Leaves opposite or sometimes sub-opposite .  Inflorescences very variable, can be terminal or usually axillary, solitary, dichasial, racemose, glomerulous or sometimes paniculate; perianth free in 4 to 5 parts or calyx calyptrate; stamens free, numerous; anthers versatile, dehiscing by longitudinal slits

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary generally inferior, occasionally semi-inferior, mostly 2, 3 or 4 (-10) locular; placentas axile, ovules radiating, sometimes pendulous; vascular supply to ovary trans-septal-Fruit indehiscent, fleshy; seeds usually numerous; embryo variable with cotyledons small and straight or elongate and curved, well developed and leafy or homogenous.

Note

Number of genera: 29 genera: Acca, Accara, Amomyrtella, Amomyrtus, Blepharocalyx, Calycolpus, Calycorectes, Calyptranthes, Campomanesia, Chamguava, Eugenia, Hexachlamys, Legrandia, Luma, Marlierea, Mosiera, Myrceugenia, Myrcia, Myrcianthes, Myrciaria, Myrrhinium, Myrteola, Neomitranthes, Pimenta, Plinia, Psidium, Siphoneugena, Tepualia, Ugni.

Diagnostic

Blepharocalyx: seed testa soft, embryo c-shaped, perianth 4-merous, parts free, arranged in a distinctive square upon ovary; inflorescences in complex branching dichasia of up to 35 flowers; single very variable and widely distributed species in Brazil, Venezuela and tropical Argentina. Eugenia: seed testa soft; embryo homogenous resembling a bean; perianth mostly 4-merous, parts free, flowers often subtended by evident, conspicuous bracts; inflorescences solitary, in fascicles, spikes or racemes; widely distributed throughout the Neotropics, > 1,000 species. Myrcia s.l.: seed testa soft; embryo membranous, plicate with long, distinct hypocotyl; perianth mostly 5-merous, calyx lobes free or fused, tearing open irregularly or circumscissile and falling as a calyptra; inflorescences in panicles; widely distributed throughout the Neotropics, > 700 species. Myrceugenia: seed testa soft; embryo membranous, plicate with long, distinct hypocotyl; perianth mostly 4-merous, parts free (rarely circumscissile), valvate; inflorescences solitary or in dichasia; common in Brazil to Argentina: Chile and the Juan Fernandez Islands. Pimenta: seed testa hard in all but one species, embryo c-shaped, perianth (4-)5-merous, parts free; inflorescences in complex branching dichasia of many flowers; extremely aromatic plant; common in central America, the Caribbean and southern Brazil. Psidium: seed testa hard, embryo c-shaped, perianth mostly 4-merous, parts free to fused often tearing open irregualarly; inflorescences solitary or in panicles; common throughout South America. Myrciaria, Neomitranthes, Plinia and Siphoneugena: seed testa soft; embryo homogenous resembling a bean; perianth mostly 4-merous, parts free or fused and falling as a circumscissile but open ring or tearing irregularly; inflorescences mostly sessile and in glomerules; central America, the Caribbean and particularly common in southern Brazil. Observe texture of seed testa. Observe embryo shape and size. Observe number of perianth parts. Observe inflorescence architecture. Note collection locality. Key differences from similar families: The families listed below differ from Myrtaceae in the following characters: Clusiaceae: plants usually with latex; leaves sometimes with dark resin-filled dots; flowers often unisexual; ovarysuperior. Malpighiaceae: leaves without translucent dots, an interpetiolar scar often present; flowers with clawed petals, few stamens; calyx with prominentglands at the base on the outer surface. Oleaceae: leaves sometimes serrate; no part of plant bearing pellucidgland dots; stamens 2; ovarysuperior. Melastomataceae (especially Mouriri): plants without translucent dots; no part of plant bearing pellucidgland dots; stamens <20, anthers sickle shaped and isomerous; inflorescences often cymose. Rubiaceae (especially in fruit): plants without translucent dots; interpetiolar stipules distinct in most specimens; corolla tubular; stamens 4-5. Rutaceae (species with simple leaves): leaves alternate; flowers with few stamens; prominent intrastaminal nectary-disc; ovarysuperior. Opposite, simple leaves. Pellucidgland dots on leaves and often other parts. Leaves aromatic when crushed. Intramarginal collecting vein present. Inferior ovary. No evident stipules. Many (>100) stamens. Distinguishing characters (always present): No characters are ALWAYS present.

Distribution

All genera listed are native, and all but Eugenia are endemic to the Neotropics.  Psidium (Guava), Eugeniauniflora (Pitanga) and Myrciariacauliflora (Jaboticaba) are widely cultivated for fruit, jams and juices. Syzygiumjambos and various Eucalyptus species are introduced, cultivated (for fruit and timber/shade respectively) and are often naturalized. Acca O. Berg: Brazil to Peru and Uruguay. Accara Landrum: Brazil. Amomyrtella Kausel: Bolivia and Northern Argentina. Amomyrtus (Burret) Legrand & Kausel: Chile, just into W. Argentina. Blepharocalyx O. Berg: Brazil, Bolivia and Paraguay, Chile and Argentina. Calycolpus O. Berg: Panama and Colombia, Venezuela to Peru and Trinidad, Guyana and Northern Brazil. Calycorectes O. Berg: Cuba, Mexico south to Northern Argentina. Calyptranthes Sw.: Florida and Caribbean, Mexico south to Northern Argentina. Campomanesia Ruíz & Pavón: Brazil north to Venezuela and Trinidad, west to Colombia and Peru and south to Northern Argentina. Chamguava Landrum: Mexico (Guerrero, Chiapas) to Honduras and Panama. Eugenia L. Pantropical - in the Neotropics: Southern Florida and Caribbean and from Mexico to Argentina. Gomidesia O. Berg: Brazil north to Venezuela, Guyana and the Caribbean to Hispaniola, south into Paraguay and Argentina. Hexachlamys O. Berg: Southern Brazil and Paraguay to Bolivia and Northern Argentina. Legrandia Kausel: Chile. Luma A. Gray: Peru: Chile and Argentina. Marlierea Cambess.: Trinidad-Tobago and Windward Is., Costa Rica to Colombia, Venezuela and the Guianas and Northern Brazil. Mosiera Small: Southern Florida and Caribbean. Myrceugenia O. Berg: Brazil to Argentina, Chile and Juan Fernandez Is. Myrcia DC. ex Guillemin: Mexico and Caribbean south to Argentina. Myrcianthes O. Berg: Florida and Caribbean, Mexico south to Chile, Argentina and Uruguay. Myrciaria O. Berg: Guatemala and Belize south to Paraguay and Northern Argentina. Myrrhinium Schott: Ecuador and Peru to Southern Brazil and Northern Argentina. Myrteola O. Berg: From the Andes of Colombia south to Tierra del Fuego and Falkland Is. Neomitranthes Legrand: SE. and Southern Brazil. Pimenta Lindl.: Caribbean from Cuba to Trinidad, Mexico (Veracruz, Oaxaca) to Panama, Southern Bolivia, Southern and SE. Brazil. Plinia L.: Caribbean: Costa Rica south through tropical South America to Argentina. Psidium L.: Southern Mexico and Caribbean through tropical South America to Northern Argentina. Siphoneugena O. Berg: Brazil north to Venezuela, the Guianas and Caribbean to Puerto Rico, south into Argentina. Tepualia Griseb.: Chile. Ugni Turcz.: Guatemala to Guyana (Mt. Roraima) and Chile, Juan Fernandez Is.

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: Clusiaceae: latex present, no aroma when crushed, primary veins parallel, ovary superior. Oleaceae: no aroma when crushed, leaves without pellucid glands, stamens few. Rubiaceae: no aroma when crushed, interpetiolar stipules distinct, leaves without pellucid glands, corolla sympetalous, stamens 4–5. Rutaceae (taxa with simple leaves): flowers with few stamens, ovary superior.

Morphology General Habit

Trees, treelets or shrubs, bark peeling, usually mottled

Morphology Leaves Stipules

Stipules absent

Morphology Leaves

Leaves simple, opposite, or decussate to whorled, margins entire, lamina with pellucid gland dots, distinct intra-marginal veins and a strong smell of camphor when crushed

Morphology Reproductive morphology Inflorescences

Inflorescences with flowers solitary, fasciculate, in dichasia, racemes or bottle-brush-like structures

Morphology Reproductive morphology Flowers

Flowers usually actinomorphic; hypanthium well developed; calyx 4–5-merous, lobes free or fused, occasionally calyptrate or operculate; corolla 4–8(–12)-merous, petals free or occasionally operculate, mostly white, sometimes yellow, pink or red; stamens generally numerous, rarely 10 or fewer; ovary inferior, rarely semiinferior, (1–)2–6(–12)-locular, (1–)2–numerous, placentation mostly axile; single style and stigma

Morphology Reproductive morphology Fruits

Fruit woody and capsular or fleshy berries

Morphology Reproductive morphology Seeds

Seeds mostly without endosperm, fleshy fruits with 1–2(–10) seeds per fruit, seed coat papery or hard with leafy and folded or fleshy homogenous (or distinct) cotyledons, or embryo bent or circinnate; dry fruits with numerous small, thin-walled seeds.

Distribution

Pantropical family with ca. 140 genera and ca. 5,500 species, with temperate centres of diversity in temperate Australia and at high altitudes in Southeast Asia and southern South America. The largest genus in temperate biomes is Eucalyptus. One species, Myrtus communis, commonly occurs around the Mediterranean.

Note

Trees, bark peeling. Leaves simple, opposite with marginal veins, pellucid dots, camphor smell when crushed, margins entire. Flowers usually with many stamens; ovary inferior or semi-inferior. Fruits capsular or fleshy.

Description Author

Eve Lucas

Myrtaceae, F. White. Flora Zambesiaca 4. 1978

Morphology General Habit

Trees, shrubs or rhizomatous, geoxylic suffrutices

Morphology Leaves

Leaves usually opposite or subopposite, rarely alternate, ternate, or in fours, simple, entire, often coriaceous, pellucid-punctate

Morphology Leaves Stipules

Stipules absent

Morphology Reproductive morphology Inflorescences

Inflorescence axillary or terminal, paniculate, thyrsoid, umbellate, cymose, racemose, or flowers solitary or fasciculate

Morphology Reproductive morphology Flowers

Flowers mostly bisexual, sometimes unisexual by abortion, actinomorphic, partly or completely epigynous

Morphology Reproductive morphology Flowers Calyx

Sepals (0)4–5, often persistent, rarely accrescent, sometimes fused to form an operculum, often with punctate glands

Morphology Reproductive morphology Flowers Corolla

Petals (0)4–5, imbricate, free or coherent to form a calyptra or fused to form an operculum, often with punctate glands

Morphology Reproductive morphology Flowers Androecium

Stamens usually numerous, free or basally connate; filaments often coiled or folded in the bud; anthers basifixed or dorsifixed, connective sometimes with an apical gland

Morphology Reproductive morphology Flowers Gynoecium

Ovary inferior or half-inferior, with (1)2–5(10) locules; septa sometimes incomplete; placentation axile or parietal and then often with deeply intruded placentae; ovules 1 to numerous per locule or placenta; style 1, punctiform, capitate, funnel-shaped or shallowly 2–3-lobed at the apex

Morphology Reproductive morphology Fruits

Fruit a berry, drupe or loculicidal capsule which only dehisces near the apex, rarely nut-like and indehiscent

Morphology Reproductive morphology Seeds

Seeds 1 to many per locule; endosperm absent or scanty; embryo straight or incurved

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

Morphology General Habit

Unarmed shrubs or trees with simple, entire, opposite or alternate leaves, these pinnate- veined and usually punctate with resinous or pellucid glands; principal lateral veins usually united toward the margins by an often obscure submarginal vein extending the length of the blade; stipules absent

Morphology Reproductive morphology Flowers

Flowers usually perfect, regular or essentially so Flowers axillary or terminal, solitary or in bracteate inflorescences with opposite branching, usually modified in various ways, e.g. (a) elongation of the axis and reduction of the lateral branches to one flower each, forming a raceme; (b) suppression of the axis and reduction of the lateral branches to one flower, forming ‘glomerules’ or umbel-like clusters; (c) reduction of the lateral branches to one pair, these arising just below the flower terminating the main axis, forming a ‘dichasium’; (d) elongation of both central axis and lateral branches, resulting in a panicle; and (e) transitional forms in which a panicle terminates in triads or dichasia

Morphology Reproductive morphology Flowers Corolla

Petals usually 4 or 5, or sometimes absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens indefinitely many, in one to many series originating around the margin of the thickened calyx-disc, usually inflexed in bud; anthers mostly 2-celled, usually opening by longitudinal slits

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary 2–many-celled, bearing a simple, elongate style with a small capitate stigma; ovules 2 or more to each cell, borne on axial or parietal placentas Ovary inferior, the calyx-tube (‘hypanthium’) adnate to the ovary its whole length or sometimes prolonged beyond it; calyx-lobes usually 4 or 5, either distinct and subequal, or the calyx more or less closed and rupturing irregularly at anthesis, or else the calyx closed and circumscissile, the top lifting off like a lid

Morphology Reproductive morphology Fruits

Fruit a berry, drupe or capsule; seeds usually without endosperm.

Distribution

A family of perhaps 60 genera and nearly 3,000 species, chiefly in the tropics, but well represented in subtropical and temperate areas of the Southern Hemisphere.

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

Note

Trees, bark peeling. Leaves simple, opposite with clear intra-marginal veins, pellucid dots, smell of camphor when crushed, margins entire. Flowers with many stamens, ovary inferior or semi-inferior. Fruits mostly fleshy in the tropics.

Recognition

Characters of similar families: Clusiaceae: latex present, primary veins parallel, ovary superior. Malpighiaceae: leaves without pellucid glands, clawed petals, few stamens, glands on outer calyx. Rubiaceae: no pellucid glands, interpetiolar stipules distinct, corolla sympetalous, stamens 4–5. Rutaceae: simple or compound, alternate, flowers with few stamens, ovary superior.

Morphology General Habit

Trees, treelets or shrubs, bark peeling, mottled, often coloured

Morphology Leaves Stipules

Stipules absent

Morphology Leaves

Leaves simple, opposite, margins entire, lamina with pellucid gland dots, distinct intra-marginal veins and a strong smell of camphor when crushed

Morphology Reproductive morphology Inflorescences

Inflorescences with flowers solitary, fasciculate, in dichasia, racemes, panicles or bottle-brush like structures

Morphology Reproductive morphology Flowers

Flowers usually actinomorphic; hypanthium well developed; calyx 4–5-merous, lobes free or fused, occasionally calyptrate or operculate; corolla 4–8(–12)-merous, petals free or occasionally operculate, mostly white, sometimes yellow, pink or red; stamens generally numerous, rarely 10 or less; ovary inferior, rarely semiinferior, (1–)2–6(–12)-locular, ovules (1–)2-numerous, placentation mostly axile; single style and stigma

Morphology Reproductive morphology Fruits

Fruit mostly fleshy berries in the tropics, alternatively capsular

Morphology Reproductive morphology Seeds

Seeds mostly without endosperm, fleshy fruits with 1–2(–10) seeds per fruit, seed coat papery or hard with leafy and folded or fleshy homogenous (or distinct) cotyledons, or embryo bent or circinnate respectively; dry fruits with numerous small, thin-walled seeds.

Distribution

Pantropical family with c. 140 genera and c. 5,500 species. Tropical centres of diversity in the South American, South-East Asian and Australian rain forests. The principal Old World genus is Syzygium; in the Neotropics, the most speciose genera are Eugenia, Myrcia and Psidium.

Description Author

Eve Lucas

Myrtaceae, B. Verdcourt, B.Sc., Ph.D.. Flora of Tropical East Africa. 2001

Morphology General Habit

Trees, shrubs or occasionally pyrophytic subshrubs with massive rootstocks; usually evergreen; pith with internal phloem

Morphology Leaves

Leaves simple, predominantly opposite, often coriaceous, mostly entire, glandular-punctate; stipules absent or very reduced

Morphology Reproductive morphology Flowers

Flowers mostly regular, hermaphrodite or unisexual, solitary or in simple to complex inflorescences; bracteoles often present

Morphology Reproductive morphology Flowers Hypanthium

Hypanthium (“calyx-tube”) ± adnate to the ovary; lobes 3–6(–10), imbricate, valvate, splitting irregularly or forming an operculum

Morphology Reproductive morphology Flowers Corolla

Petals 4–5(–6) or rarely absent, included on the margin of the disc lining the calyx-tube, imbricate or forming an operculum

Morphology Reproductive morphology Flowers Androecium

Stamens numerous, rarely only 4, 5 or 10, included on the disc margin in 1 or more rows, straight, inflexed or twice folded in bud; filaments free or connate at the base into a short tube or in 4–5 bundles opposite the petals; anthers small, 2-locular, opening by slits or less often by apical pores; connective sometimes tipped by a gland

Morphology Reproductive morphology Flowers Gynoecium

Ovary inferior or ± superior, (1–)2–5(–16)-locular with axile or rarely parietal placentation; ovules (1–)2–many, anatropous to campylotropous; style terminal (absent in one genus)

Morphology Reproductive morphology Fruits

Fruit a berry or capsule (less often a drupe or nut), (1–)few(–many)-seeded, indehiscent or loculicidally dehiscent

Morphology Reproductive morphology Seeds

Seeds without or with very little endosperm; embryo straight, incurved, circular or spiral

Heteropyxidaceae, A. Fernandes. Flora Zambesiaca 4. 1978

Morphology General Habit

Aromatic trees or shrubs

Morphology Leaves

Leaves alternate, simple, attenuate into a ± long petiole, pellucid-punctate

Morphology Reproductive morphology Flowers

Flowers dioecious by abortion, actinomorphic, yellowish, sweet-scented Female flowers: perianth as in male; staminodes (4)5–8, minute; ovary free, superior, 2(3)-locular, gland-dotted, with ¥ ovules inserted on an axile placenta; style inserted in a depression of the ovary apex, cylindric, glabrous or pilose, with a large, papillose and capitate stigma Male flowers: receptacle cyathiform, with (4)5 imbricate segments; petals 4(5), perigynous, free, imbricate, gland-dotted; stamens (4)5–8(9–10), perigynous, free, exserted, (4)5 opposite to the petals, the others to the receptacle segments, filaments straight; anthers dorsifixed, dehiscing longitudinally, with 1–3 glands on the back of the connective; disk perigynous, lining the lower 1/2 of the resceptacle, glabrous or ± pilose; pistillode turbinate, with a sessile or short style and a papillose stigma

sex Male

Male flowers: receptacle cyathiform, with (4)5 imbricate segments; petals 4(5), perigynous, free, imbricate, gland-dotted; stamens (4)5–8(9–10), perigynous, free, exserted, (4)5 opposite to the petals, the others to the receptacle segments, filaments straight; anthers dorsifixed, dehiscing longitudinally, with 1–3 glands on the back of the connective; disk perigynous, lining the lower 1/2 of the resceptacle, glabrous or ± pilose; pistillode turbinate, with a sessile or short style and a papillose stigma

sex Female

Female flowers: perianth as in male; staminodes (4)5–8, minute; ovary free, superior, 2(3)-locular, gland-dotted, with ¥ ovules inserted on an axile placenta; style inserted in a depression of the ovary apex, cylindric, glabrous or pilose, with a large, papillose and capitate stigma

Morphology Reproductive morphology Fruits

Fruit a small loculicidal 2(3)-valved capsule

Morphology Reproductive morphology Seeds

Seeds ± straight, the outer ones winged at the extremities, without endosperm