The World Flora Online

SELECTED REFERENCES

Wood, C. E. Jr. 1958. The genera of the woody Ranales in the southeastern United States. J. Arnold Arbor. 39: 296-346.

Shrubs to tall trees , evergreen or rarely deciduous ( Cassytha a parasitic vine with leaves reduced to scales), usually aromatic. Leaves alternate, rarely whorled or opposite, simple, without stipules, petiolate. Leaf blade: unlobed (unlobed or lobed in Sassafras ), margins entire, occasionally with domatia (crevices or hollows serving as lodging for mites) in axils of main lateral veins (in Cinnamomum ). Inflorescences in axils of leaves or deciduous bracts, panicles (rarely heads), racemes, compound cymes, or pseudoumbels (spikes in Cassytha ), sometimes enclosed by decussate bracts. Flowers bisexual or unisexual, bisexual only, or staminate and pistillate on different plants, or staminate and bisexual on some plants, pistillate and bisexual on others; flowers usually yellow to greenish or white, rarely reddish; hypanthium well developed, resembling calyx tube, tepals and stamens perigynous; tepals 6(-9), in 2(-3) whorls of 3, sepaloid, equal or rarely unequal, if unequal then usually outer 3 smaller than inner 3 (occasionally absent in Litsea ); stamens (3-)9(-12), in whorls of 3, but 1 or more whorls frequently staminodial or absent; stamens of 3d whorl with 2 glands near base; anthers 2- or 4-locular, locules opening by valves; pistil 1, 1-carpellate; ovary 1-locular; placentation basal; ovule 1; stigma subsessile, discoid or capitate. Fruits drupes, drupe borne on pedicel with or without persistent tepals at base, or seated in ± deeply cup-shaped receptacle (cupule), or enclosed in accrescent floral tube. Seed 1; endosperm absent.

Appareil végétatif soit herbacé (Cassytha) soit ligneux. Ainsi, le genre Cassytha se sépare de tous les autres de cette famille par son aspect: fines tiges volubiles, sans feuilles, et par son mode de vie: parasite à la façon des Cuscutes. Par contre, les autres Lauraceae sont des arbustes ou des arbres parfois très grands: Beilschmiedia congolana Robyns et Wilczek atteint 50 m de haut avec un fût de 30 m de long et 90 cm de diamètre à la base. L'écorce est souvent aromatique et peut être utilisée comme condiment à la manière de celle du Cannellier de Ceylan (Cinnamomum zeyla-nicum Nees) autre Lauracée introduite dans les cultures. Les feuilles sont toujours simples, sans stipules, à limbe entier (du moins dans les espèces africaines) ordinairement persistantes et souvent coriaces , avec un pétiole canaliculé dessus. Le plus souvent elles sont glabres et brillantes; cependant certaines espèces du genre Beilschmiedia ont les feuilles pubescentes sous les nervures comme B. Corbisieri Robyns et Wilczek ou tomentelleuses sous les nervures comme B. alata Rob. et Wilcz. ou même tomen-telleuses sur toute la face inférieure comme B. fulva et B. congolana des mêmes auteurs. La nervation est penninerve, rarement palminerve. Des poches sécrétrices isolées dans l'épaisseur du limbe donnent parfois des ponctuations±visibles à la loupe par transparence: B.fulva Rob. et Wilcz., B. Mannii (Meissn.) Benth. et Hook. les montrent dans les feuilles jeunes, minces. Quelques espèces présentent un limbe auriculé ou ± cordé à la base. Les inflorescences sont axillaires, subterminales. Ce sont, pour les espèces africaines, des grappes de cymes, à ramifications ± velues, avec bractées. Les fleurs, parfois odorantes, sont toujours petites, de i à io mm de long, trimères, rarement dimères, hermaphrodites, polygames ou dioïques, régulières. Les divisions du périanthe sont sépaloïdes mais parfois aussi colorées en jaune ou en rouge; ces tépales sont libres, insérés en deux cycles de trois pièces sur un réceptacle en coupe de forme variable. Le tépale médian du ier cycle est postérieur; la préfloraison est imbriquée ou valvaire. L'androcée comprend quatre verticilles de trois pièces chacun ; le plus souvent, les deux verticilles externes, soit 6 étamines, sont de forme voisine, avec les anthères introrses; le 3e verticille est accompagné de deux masses de tissus mous, dites glandes, arrondies ou réniformes, soudées au filet ou au réceptacle; les anthères sont latérales ou extrorses dans les espèces africaines. Parfois (Hypodaphnis) les glandes sont fixées au filet du 2e cycle. Quant au 4e cycle, il est représenté par des staminodes±développés, parfois nuls. Fréquemment le 3e cycle est stérile; le 1er et le 2e peuvent l'être également mais jusqu'à présent dans des genres non africains. La division des Lauraceae en tribus par Nées von Esenbeck 1836) n'était pas basée sur l'androcée. Par contre, les auteurs ayant étudié la famille après Nees ont fondé les définitions des genres et des tribus surtout sur les caractères staminaux. La connaissance précise des étamines est donc nécessaire pour l'étude de toute Lauracée. C'est ainsi que les anthères pouvant comporter une, deux ou quatre loges polliniques fermées par un, deux ou quatre clapets, on peut en tirer une première division en trois sous-familles. Ce mode très particulier de déhiscence des anthères est caractérisé par des valvules discoïdes obturant la loge pollinique ; ces valvules se détachent circulairement par la partie inférieure pour donner issue au pollen et restent longtemps après l'ouverture relevées et retenues par un bord sur le haut de la loge vide ; il est commun aux Lauraceae, Berbéridaceae et à certaines Monimiaceae. Le pistil est au contraire très uniforme dans toute la famille, toujours formé d'un ovaire supère (infère chez Hypodaphnis) à une seule loge uniovulée (rarement à 2 ovules) surmonté d'un seul style (du moins dans les genres africains) avec stigmate effilé ou capité. L'ovule est anatrope, pendant. Le fruit est une baie ou une drupe, libre ou enveloppée entièrement ou partiellement dans le calice accru. La graine est sans albumen, l'embryon est droit, à cotylédons charnus, plans-convexes, à radicule supère.

Arbustes'à arbres, rarement herbes volubiles et parasites, pourvus de glandes aromatiques dans les feuilles, les fleurs et l'écorce.'Feuilles'ordinairement alternes, parfois opposées ou subopposées, simples, rarement réduites à de petites écailles, en général coriaces et persistantes, penninerves, parfois à 3-5 nervures subbasilaires, dépourvues de stipules.'Inflorescences'axillaires ou terminales, en cymes, racémes ou panicules; bractées présentes; bractéoles absentes sauf dans le genre'Cassytha .'Fleurs'☿ ou rarement ♂ ♀, petites, verdâtres, jaunâtres, rosâtres ou blanchâtres, (2) 3-mères, ± périgynes et à réceptacle concave à ± tubulaire; périgone en 2 verticilles (2) 3-mères et subégaux, à préfloraison imbriquée; androcée à (6-8) 9-12 étamines en 3-4 verticilles, dont l'interne ou parfois les 2 internes stériles (staminodes); étamines du 3e verticille généralement entremêlées ou pourvues de glandes charnues; anthères à 2 loges ou à 4 loges superposées 2 par 2 ou rarement parallèles 2 à 2 et s'ouvrant de bas en haut par des valves; gynécée syncarpe, à 1 style et à stigmate simple; ovaire inséré dans le creux du réceptacle, 1-loculaire, à 1 ovule apical et pendant.'Fruits'bacciformes ou drupacés, nus ou entourés à la base par le réceptacle persistant et charnu en forme de cupule.'Graines exalbuminées; embryon à axe vertical ou transversal.\n\t\t\tFamille comprenant actuellement ± 50 genres et ± 1.500 espèces généralement sempervirentes, répandues surtout dans les régions subtropicales et tropicales, à centres principaux de dispersion en Asie orientale méridionale et au Brésil. Certaines espèces sont économiques, telles que'Laurus nobilis'L.,'Persea americana'Mill, et divers'Cinnamomum .

Seed pendulous, without endosperm; testa membranous; embryo straight; cotyledons thick, fleshy; radicle superior Fruit baccate or drupaceous Ovule solitary, pendulous Ovary superior, rarely inferior, 1-celled; style terminal, simple; stigma small Stamens typically in 4 whorls, often the fourth row suppressed or reduced to staminodes; filaments sometimes glandular at the base, very rarely the glands fused into a disk; anthers continuous with the filament, 2–or 4-valved, cells superposed or more or less collateral, opening from the base upwards by flaps, introrse or sometimes the third whorl extrorse Petals absent Calyx usually inferior; tube sometimes enlarging in fruit; lobes usually 6, imbricate Leaves alternate, rarely opposite or subopposite, coriaceous and evergreen, variously nerved; stipules absent Trees or shrubs, very rarely twining parasitic herbs, all parts with aromatic oil-glands Flowers small, greenish or yellowish, usually cymose or racemose, hermaphrodite, polygamous or dioecious, actinomorphic Fruit baccate or drupaceous Ovule solitary, pendulous Ovary superior, rarely inferior, 1-celled; style terminal, simple; stigma small Stamens typically in 4 whorls, often the fourth row suppressed or reduced to staminodes; filaments sometimes glandular at the base, very rarely the glands fused into a disk; anthers continuous with the filament, 2–or 4-valved, cells superposed or more or less collateral, opening from the base upwards by flaps, introrse or sometimes the third whorl extrorse Petals absent Calyx usually inferior; tube sometimes enlarging in fruit; lobes usually 6, imbricate Leaves alternate, rarely opposite or subopposite, coriaceous and evergreen, variously nerved; stipules absent Trees or shrubs, very rarely twining parasitic herbs, all parts with aromatic oil-glands Flowers small, greenish or yellowish, usually cymose or racemose, hermaphrodite, polygamous or dioecious, actinomorphic

Inflorescences of cymes or paniculately arranged cymes, racemes or heads; flowers rarely solitary, axillary, usually subterminal; bracts simple, involucrate, deciduous; bracteoles present or lacking Flowers hermaphrodite, unisexual by abortion, greenish, yellowish or reddish, actinomorphic Receptacle campanulate, cup-shaped or urceolate, rarely oblong, sometimes accrescent after flowering Ovary superior, rarely inferior (in Africa, Hypodaphnis), 1-locular; ovule solitary, anatropous from near the apex; style terminal; stigma small, discoid, pointed or unilaterally widened, rarely 2–3-lobed Fruit baccate or drupaceous, indehiscent, free or ± surrounded by the accrescent receptacle, or completely enclosed within it, often borne on a thickened fruiting pedicel Perianth (2)3-merous in 2 whorls, not differentiated into calyx and corolla; tepals (4)6(8) free or ± connate, all similar or the outer ones smaller than the inner, imbricate or valvate in bud, deciduous or persistent Stamens usually in 4 whorls inserted in the throat of the receptacle, or at the base of and opposite to the tepals, usually the fourth whorl, and sometimes the third whorl staminodal; filaments usually present and free, ± flattened, varying from very short to much longer than the anthers, those of the inner whorls mostly with a pair of globose glands at the sides or at the base (less often the glands attached to the receptacle, or sometimes the outer stamens with glands at the base); anthers basifixed, 2–4-celled, rarely 1-celled by confluence, cells ± collateral, or superposed (in 4-celled anthers), dehiscing from the base upwards; staminodes tepaloid, sagittate or ligulate Leaves alternate, rarely opposite or subopposite, entire, coriaceous, rarely membranaceous, pinnately nerved or 3–5-nerved from near the base, usually net-veined, leaves reduced to small scales in Cassytha; stipules lacking Evergreen monoecious, or dioecious polygamous trees or shrubs, rarely leafless twining parasitic herbs with haustoria (Cassytha), all parts usually with aromatic oil glands Seed 1; testa membranaceous to coriaceous, sometimes adnate to the pericarp and indistinct; endosperm lacking; embryo straight; radicle superior, cotyledons fleshy, sometimes connate Flowers hermaphrodite, unisexual by abortion, greenish, yellowish or reddish, actinomorphic Receptacle campanulate, cup-shaped or urceolate, rarely oblong, sometimes accrescent after flowering Ovary superior, rarely inferior (in Africa, Hypodaphnis), 1-locular; ovule solitary, anatropous from near the apex; style terminal; stigma small, discoid, pointed or unilaterally widened, rarely 2–3-lobed Fruit baccate or drupaceous, indehiscent, free or ± surrounded by the accrescent receptacle, or completely enclosed within it, often borne on a thickened fruiting pedicel Perianth (2)3-merous in 2 whorls, not differentiated into calyx and corolla; tepals (4)6(8) free or ± connate, all similar or the outer ones smaller than the inner, imbricate or valvate in bud, deciduous or persistent Stamens usually in 4 whorls inserted in the throat of the receptacle, or at the base of and opposite to the tepals, usually the fourth whorl, and sometimes the third whorl staminodal; filaments usually present and free, ± flattened, varying from very short to much longer than the anthers, those of the inner whorls mostly with a pair of globose glands at the sides or at the base (less often the glands attached to the receptacle, or sometimes the outer stamens with glands at the base); anthers basifixed, 2–4-celled, rarely 1-celled by confluence, cells ± collateral, or superposed (in 4-celled anthers), dehiscing from the base upwards; staminodes tepaloid, sagittate or ligulate Leaves alternate, rarely opposite or subopposite, entire, coriaceous, rarely membranaceous, pinnately nerved or 3–5-nerved from near the base, usually net-veined, leaves reduced to small scales in Cassytha; stipules lacking Evergreen monoecious, or dioecious polygamous trees or shrubs, rarely leafless twining parasitic herbs with haustoria (Cassytha), all parts usually with aromatic oil glands Seed 1; testa membranaceous to coriaceous, sometimes adnate to the pericarp and indistinct; endosperm lacking; embryo straight; radicle superior, cotyledons fleshy, sometimes connate

Fls perfect or unisexual, regular, perigynous; perianth of (4)6 sepaloid members in 2 cycles; stamens 3–12, most often 9, each filament often with a pair of basilateral nectariferous appendages, the innermost set of 3 stamens often reduced to staminodes; anthers opening by 2 or 4 uplifting valves; pollen inaperturate or sometimes monosulcate; ovary superior, unilocular and apparently unicarpellate, with a single pendulous ovule; fr a l-seeded berry or drupe; seeds with large, straight, dicotyledonous embryo and without endosperm; aromatic trees and shrubs with alternate, simple, exstipulate, entire or lobed leaves and small, usually yellowish fls. 30–50/2000+.

Trees or shrubs (Cassytha a twining parasitic perennial herb with leaves reduced or absent), mostly evergreen (deciduous in temperate regions), sometimes dioecious. Bark and foliage usually aromatic. Leaves usually alternate, occasionally opposite or subopposite or verticillate, simple, usually entire, rarely lobed (Sassafras), mostly pinninerved and subpalmately veined, or often triplinerved, usually punctate and leathery, estipulate. Flowers in usually axillary, occasionally subterminal, panicles, spikes, racemes, or pseudoumbels, generally bisexual, sometimes unisexual, actinomorphic, mostly 3-merous, also 2-merous, small, greenish, yellowish, or white. Perianth biseriate, of usually 4 or 6 basally connate usually undifferentiated sepal-like segments, deciduous or persistent; perianth tube usually persisting as a cupule at base of fruit. Androecium typically of 4 whorls of 3 stamens each, adnate to perianth tube, innermost whorl rarely united, usually reduced to staminodes; filaments usually free, 3rd whorl usually bearing 2 usually sessile and distinct basal glandular protuberances; anthers basifixed, 2-celled or 4-celled at anthesis, those of 2 outer whorls mostly introrse, inner 3rd whorl extrorse, dehiscing by flaplike valves opening upward. Pistil 1; ovary usually superior, 1-loculed; ovule solitary, anatropous, pendulous, placentation parietal; style 1; stigma 1, occasionally 2- or 3-lobed. Fruit a drupe or berry usually surrounded at base by enlarged and often persistent perianth tube seated on a large receptacle or pedicel. Seed with large straight embryo; endosperm absent.

Ovary unicarpellate, sessile, free or in a few genera adhering to the calyx-tube and appearing inferior, 1-locular; ovule 1, pendulous, anatropous Stamens and staminodes usually twice as many as perianth-segments, in 4 (rarely more) whorls; innermost whorl and occasionally 2 outer whorls reduced to staminodes; filaments of third whorl usually with 2 ± stalked or sessile glands on either side, the stalk sometimes adnate to the filament, rarely all or none with glands; anthers with 2-4 thecae opening by valves, those of the outer stamens introrse, those of the third series often extrorse Perianth-lobes usually ± equal, in 2 whorls of (2-)3, imbricate or in ± one whorl Seeds with endosperm; cotyledons large Fruit a 1-seeded berry or dry but indehiscent Mostly evergreen trees (often tall with buttresses), shrubs or, in Cassytha, parasitic twiners with scale-like leaves Flowers usually small, mostly green or yellow, regular, unisexual or hermaphrodite, in cymes, false umbels, heads, spikes, panicles or occasionally solitary; bracts small or absent or, in a few genera, forming an involucre at the base of the inflorescences or partial inflorescences Leaves simple, alternate or occasionally opposite, entire to slightly undulate or, in about six SPECIES, lobed, usually coriaceous; stipules absent Stamens and staminodes usually twice as many as perianth-segments, in 4 (rarely more) whorls; innermost whorl and occasionally 2 outer whorls reduced to staminodes; filaments of third whorl usually with 2 ± stalked or sessile glands on either side, the stalk sometimes adnate to the filament, rarely all or none with glands; anthers with 2-4 thecae opening by valves, those of the outer stamens introrse, those of the third series often extrorse Perianth-lobes usually ± equal, in 2 whorls of (2-)3, imbricate or in ± one whorl Seeds with endosperm; cotyledons large Fruit a 1-seeded berry or dry but indehiscent Mostly evergreen trees (often tall with buttresses), shrubs or, in Cassytha, parasitic twiners with scale-like leaves Flowers usually small, mostly green or yellow, regular, unisexual or hermaphrodite, in cymes, false umbels, heads, spikes, panicles or occasionally solitary; bracts small or absent or, in a few genera, forming an involucre at the base of the inflorescences or partial inflorescences Leaves simple, alternate or occasionally opposite, entire to slightly undulate or, in about six SPECIES, lobed, usually coriaceous; stipules absent