Monimiaceae Juss.

Rener, S. (2009). Neotropical Monimiaceae.

Morphology

Description

Evergreen scambling shrubs, treelets or trees, with spherical oil cells in all parts of the plants. Leaves oppposite, decussate or in whorls of 3-4, simple , exstipulate , those of a pair often unequal in size, with simple or stellate hairs, glabrescent, the margin variously serrate , dentate , or entire . Inflorescences axillary or cauliflorous , cymose or fasciculate . Flowers radial, unisexual or rarely bisexual , plants dioecious , floral cup ( receptacle ) well-developed (the perigon perigynous ), subglobose or cup-shaped, tepals 3 to numerous, petaloid , sepaloid, or connate and forming a calyptra; stamens few to very numerous, dispersed irregularly in the floral cup, filaments lacking appendages or more rarely with paired basal nectary glands on the filaments, anthers with 4 pollen sacs dehiscing by longitudinal, lateral , or circumscissile slits; carpels 1 to numerous, free or immersed in and fused with the receptacle tissue, the stigmas and/or styles free or joined by mucilage plugs, ovules solitary, pendulous and anatropous, bitegmic, crassinucellate. Fruitingreceptacle repand and with few to many sessile or stipitate drupes, or the drupes enclosed in a fleshy receptacle and exposed at maturity by the splitting of the receptacle ; the mesocarp fleshy , rarely half covered by an orange stylar aril , the endocarp stony.

Distribution

Distribution in the Neotropics

Currently 28 genera and 195-200 species, mostly in the Malagasy floristic region, New Guinea (this has 75 species), and the Neotropics (four genera and ca. 24 species), with a few species in the rest of Malesia, Eastern Australia, and New Zealand. A single species, Xymalos monospora Baill., occurs from South Africa to Kenya, Uganda, and Cameroon.

• Hennecartia Poisson: monospecific (H. omphalandra Poisson), Argentina.
• Macropeplus Perkins: monospecific (M. ligustrinus (Tul.) Perkins) in gallery forest of southern Brazil, Paraguay, and Argentina.
• Macrotorus Perkins: monospecific (M. utriculatus (Mart.) Perkins) in gallery forest of southern Brazil, Paraguay, and Argentina.
• Mollinedia Ruiz & Pav.: ca. 20 species in understorey lowland moist forest, from Central America to the Amazon basin and in gallery forests in Brazil, Paraguay, and Argentina.
• Peumus Molina: monospecific (P. boldus Molina) included here despite being outside the Flora region, in sclerophyllous Chilean forests between 30º and 41º latitude.

Diagnostic

Distinguishing characters (always present)

• Leaves opposite, decussate or in whorls of 3 to 4.
• Flowers closed, somewhat fig-like, only the style tips or anther tips emerging from an apical ostiole.

Key differences from similar families

• Rarely confused.

Useful tips for generic identification

• An inordinate number of genera are monotypic (and hence devoid of informative generic characters).
• Several others are poorly circumscribed.
• Renner et al. 2010 paper, which has sequences for all but one genus and the majority of species.

General Description

Status

• Monimiaceae are not cultivated, with the exception of Peumus, which is cultivated in a few botanical gardens in Europe.

General notes

• The fossil record of Monimiaceae is relatively extensive. Fossils from the Upper Senonian of the eastern Cape Province (Hedycaryoxylonhortonioides Mädel) and the Upper Cretaceous (Campanian) of James Ross Island in Antarctica (Hedycaryoxylontambourissoides Poole & Gottwald) undoubtedly represent Monimiaceae. Somewhat younger fossil woods, referred to Xymaloxylonzeltenense (Louvet) Louvet (syn. Monimiaxylonzeltenense Louvet), have been described from the Early Oligocene of Oman.
• There are also leaves from Paleocene/Eocene boundary strata on King George Island, Antarctic Peninsula (Monimiophyllumantarcticum Zastawniak). Even fossil woods from the Late Eocene of Germany, namely Hedycaryoxylomsubaffine (Vater) Süss and Hortonioxylonhenericiungeri Gottwald, have been compared to Hortonia Wight ex Arn., Hedycarya Forst., and Tambourissa Sonn. [This is from S. S.Renner, unpublished manuscript, which contains all the refs.]

Notes on delimitation

• Morphologically and molecularly strongly supported as monophyletic (once Siparunaceae, Atherospermataceae, Amborellaceae, and Trimeniaceae were excluded).

Number of genera

See above.

Literature

Important literature

Philipson, W.R. 1986. Monimiaceae. In: Steenis, C.G.G.J. van, ed. Flora Malesiana Spermatophyta: flowering plants. vol.10, part 2. Revisions. Dordrecht etc., Martinus Nijhoff Publishers. 255-326.

Renner, S.S. 2004. Monimiaceae. Pp. 252-253. In: Smith, N., Mori, S.A., Henderson, A., Stevenson, D.W. & Heald, S.V. (eds.). Flowering Plants of the Neotropics. New York Botanical Garden, Princeton University Press, Princeton.

Renner, S.S., and Hausner, G. 1997. Siparunaceae, Monimiaceae. In: Harling, G. & Andersson, L. (eds.). Flora of Ecuador no. 59, Pp. 1-124. Department of Systematic Botany, University of Gothenburg, Gothenburg.Renner, S. S., J. S. Strijk, D. Strasberg, and C. Thébaud. 2010. Biogeography of the Monimiaceae (Laurales): A role for East Gondwana and long distance dispersal, but not West Gondwana. Journal of Biogeography 37(7): 1227-1238.

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

Distribution

The Monimiaceae are a family with 24 genera and c. 200 species, mainly in the warmer parts of the southern hemisphere. In New Guinea, it is represented by five genera (of which three are endemic) and 74 species, including 11 species in the liana genus Palmeria F.Muell.

Recognition

Members of the family can be recognised by the opposite leaves with entire or toothed margins, secondary venation strongly looping and joining (brochidodromus), unisexual or bisexual flowers with few to many stamens dehiscing longitudinally, and/or few to many superior ovaries often on a somewhat flattened torus and the fruits which are composed of several drupelets; several species are associated with ants which inhabit lacunae at the nodes, and the twigs may have rays in cross-section.

Morphology General Habit

Trees, shrubs, rarely lianas, evergreen. Sap absent

Morphology General Indumentum

Indumentum of simple or stellate hairs

Morphology Leaves Stipules

Stipules absent

Morphology Leaves

Leaves simple, decussate or rarely in whorls of three, margin entire or dentate, petiolate

Morphology Reproductive morphology Inflorescences

Inflorescences terminal or axillary, sometimes cauliflorous, cymose, paniculate, fasciculate or pleiochasial-Flowers unisexual, actinomorphic, receptacle usually well developed; tepals usually inconspicuous, sometimes larger and petaloid, decussate, radial or spiral-Staminate flowers with few to many stamens, filaments usually strap-shaped, short; anthers opening by slits. Pistillate flowers with or without staminodes; carpels numerous to few, sessile or stipitate, free or immersed in the receptacle, outer carpels of pistillate flowers sometimes sterile; ovule solitary, pendulous

Morphology Reproductive morphology Fruits

Fruit of separate drupes or achenes, frequently enclosed in the persistent receptacle or exposed by the various modes of splitting of the receptacle

Morphology Reproductive morphology Seeds

Seed with copious endosperm; cotyledons appressed or divergent, sometimes with serrate margins

Note

Note: The genus Lauterbachia Perkins is only known from as single specimen, the type of which was destroyed during World War II; we have included a generic description but the paucity of information concerning its morphology, requires us to omit it from the key.

Monimiaceae, B.L. Stannard. Flora Zambesiaca 9:2. 1997

Morphology General Habit

Trees, shrubs or rarely lianes, often aromatic

Morphology Leaves

Leaves opposite or less often alternate, exstipulate, simple, entire or toothed, sometimes glandular-toothed, coriaceous, sometimes minutely pellucid-punctate

Morphology Reproductive morphology Inflorescences

Inflorescences axillary or terminal, racemose, cymose or fasciculate; bracts small or absent

Morphology Reproductive morphology Flowers

Flowers hermaphrodite or unisexual, actinomorphic or more rarely zygomorphic; plants monoecious, sometimes dioecious, less often polygamous Staminodes sometimes present in female flowers

Morphology Reproductive morphology Flowers Perianth

Perianth 4–many-lobed; lobes in 2–several whorls, imbricate, rarely absent

Morphology Reproductive morphology Flowers Androecium

Stamens few to numerous, 1–2- seriate or irregular, usually free; filaments very short, sometimes with glands at the base; anthers erect, 2-locular, dehiscing by longitudinal slits, or more rarely by valves

sex Female

Staminodes sometimes present in female flowers

Morphology Reproductive morphology Flowers Gynoecium

Ovary superior; carpels usually several, rarely solitary, 1-locular; stigma sessile or with a long or short style; ovules solitary, erect or pendulous, usually anatropous

Morphology Reproductive morphology Fruits

Fruit of separate drupes, or more rarely achenes, often enclosed by the perianth or in a fleshy receptacle

Morphology Reproductive morphology Seeds

Seeds erect or pendulous, endosperm fleshy, copious

Monimiaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:1. 1954

Morphology General Habit

Trees or shrubs, rarely climbers, usually fragrant, with opposite, or rarely alternate, entire or serrate, coriaceous leaves with pellucid dots; stipules absent

Morphology Reproductive morphology Flowers

Flowers actinomorphic, rarely oblique, hermaphrodite, polygamous or unisexual, cymose or racemose, rarely solitary, small or medium-sized; inflorescence axillary or rarely terminal Female fl.: staminodes present or none; carpels several or rarely solitary, 1-celled; style short or elongated; stigma terminal; ovule solitary, erect or pendulous

Morphology Reproductive morphology Flowers Perianth

Perianth inferior, with 4 to many often connivent teeth or lobes in 2 to many series and imbricate, equal, or the outer sepaloid and the inner petaloid, rarely obsolete

Morphology Reproductive morphology Flowers Nectaries

Disk adnate to the perianth-tube

Morphology Reproductive morphology Flowers Androecium

Stamens numerous or few in 1–2 series; filaments very short, often flattened, with or without glands at the base; anthers erect, 2-celled, opening by a longitudinal slit or by valves from the base upwards

sex Female

Female fl.: staminodes present or none; carpels several or rarely solitary, 1-celled; style short or elongated; stigma terminal; ovule solitary, erect or pendulous

Morphology Reproductive morphology Flowers Gynoecium

Carpels separate in fruit, enclosed by the perianth or the latter deciduous, indehiscent, often drupaceous

Morphology Reproductive morphology Seeds

Seed erect or pendulous; testa membranous; endosperm fleshy; embryo small to half as large as the endosperm; cotyledons erect or spreading