Rhizophoraceae Pers.

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

Morphology General Habit

Trees or shrubs, frequently on maritime shores; branches swollen at the nodes

Morphology Leaves

Leaves opposite and stipulate, rarely alternate and exstipulate, leathery, simple; stipules interpetiolar, caducous

Morphology Reproductive morphology Flowers

Flowers hermaphrodite, in axillary inflorescences

Morphology Reproductive morphology Flowers Calyx

Calyx-tube adnate to the ovary or free; lobes 3–14, persistent, valvate

Morphology Reproductive morphology Flowers Corolla

Petals usually small, often notched, bifid or laciniate, convolute or inflexed in bud

Morphology Reproductive morphology Flowers Androecium

Stamens equal to or usually more than the petals in number, often in pairs opposite the petals on the edge or at the base of a perigynous disk; anthers 2–or many-celled

Morphology Reproductive morphology Flowers Gynoecium

Ovary mostly inferior, 2–6-celled or 1-celled by suppression of the septa; style simple or rarely styles several; ovules 2 in each cell, rarely more, inserted towards the apex on the inner angle of the cell

Morphology Reproductive morphology Fruits

Fruit mostly indehiscent, usually 1-seeded or the cells 1-seeded

Morphology Reproductive morphology Seeds

Seeds with or without fleshy endosperm; cotyledons terete or connate

Prance, G.T. (2009). Neotropical Rhizophoraceae.

Morphology

Description

Trees or shrubs. Leaves simple , opposite or verticillate , petiolate , margins entire or serrate , glabrous or with unicellular, simple hairs; stipule small to large, interpetiolar , caducous or subpersistent. Inflorescence of dichotomous axillary cymes, racemes or fasciculate or flowers solitary. Flowers hermaphrodite , actinomorphic ; sepals 4-7, valvate ; petals 4-7 free , equal in number and alternate to sepals, valvate , often unguiculate, margins often fimbriate or laciniate ; stamens 8-40, inserted on margin of a lobed perigynous disc ; anthers introrse, longitudinally dehiscent , dorsifiexed; ovary superior or inferior, 2-4-locular with 2 anatropous ovules in each loculus; ovules anatropous, pendulous, placentation axial; style filiform , erect , stigma 2-4- lobed . Fruit a capsule or a coriaceous , viviparous drupe , endosperm present.

Distribution

Distribution in the Neotropics

• A pantropical family of 16 genera and about 120 species.
• Three genera occur in the Neotropics.

Diagnostic

Distinguishing characters (always present)

• Opposite toothed leaves in some species.
• The viviparous drupe of Rhizophora L.
• The fimbriate or laciniate petals of Cassipourea Aubl. and Sterigmapetalum Kuhlm.
• Collecting veins occur in the leaves of some Cassipourea species.

Useful tips for generic identification

Key to genera of Neotropical Rhizophoraceae

1. Ovary inferior; fruit a viviparous drupe; plants with stiltroots... Rhizophora
1. Ovary superior; fruit a capsule, plants without stiltroots... 2

2. Flowers hermaphrodite; leaves opposite; petals fimbriate or laciniate; inflorescence of solitary flowers or sessile clusters ... Cassipourea
2. Flowers dioecious; leaves verticellate; petals laciniate; inflorescence a corymobose panicle with long peduncle... Sterigmapetalum

General Description

Number of genera

Three:

• Rhizophora
• Cassipourea
• Sterigmapetalum

General notes

• The genera Anisophyllea R.Br. ex Sabine and Polygonanthus Ducke have often been placed in this family, but they are now considered to be in a separate family, the Anisophylleaceae, which belongs in the Cucurbitales.

Status

• Native to the Neotropics, but Rhizophora and Cassipourea also occur in the Old World.

Notes on delimitation

• Previously usually associated with the Myrtales or with the Celastraceae and Elaeocarpaceae.
• The Angiosperm Phylogeny Group clearly places this family in the Malpighiales near to the Erythroxylaceae.

Literature

Important literature

Prance, G.T. and Silva, M.F. 1975. Revisão taxonômica das espécies amazônicas de Rhizophoraceae. Acta Amazonica 5 (1): 5-22.

Prance, G.T.  2001. Rhizophoraceae. Flora of Nicaragua. Monographs in Systematic Botany 85, 3: 2200-2201.

Rhizophoraceae, A. R. Torre and A. E. Gonçalves. Flora Zambesiaca 4. 1978

Morphology General Habit

Monoecious trees, shrubs or, rarely, undershrubs; young branches glabrous or glabrescent with age

Morphology Leaves

Leaves simple, petiolate, usually isomorphic, decussate (very rarely 3(4)-nate), with interpetiolar and caducous stipules, or rarely dimorphic, alternate, without stipules (Anisophyllea); nervation generally pinnate, rarely curvinerved and with 1–2 intramarginal nerves (Anisophyllea)

Morphology Reproductive morphology Inflorescences

Inflorescences simple or branched, axillary or, rarely, supra-axillary, of cymes (lax or condensed and clustered), racemes, panicles, fascicles or spikes, rarely a solitary flower

Morphology Reproductive morphology Flowers

Flowers usually bisexual, rarely unisexual or polygamous, actinomorphic, with a pair of ± connate bracteoles, rarely ebracteolate

Morphology Reproductive morphology Flowers Calyx

Calyx gamosepalous, usually ± adnate to the ovary, persistent in fruit; calyx-lobes (3)4–5(7) or 8–15 (Bruguiera), valvate

Morphology Reproductive morphology Flowers Corolla

Petals as many as the calyx-lobes and alternating with them, free, often clawed, divided above to rarely entire, usually fleshy and conduplicate, caducous or rarely persistent

Morphology Reproductive morphology Flowers Nectaries

Disk fleshy, annular or ± cup-shaped, crenate, flat or lobed, rarely absent

Morphology Reproductive morphology Flowers Androecium

Stamens usually twice as many as the petals, sometimes ¥ (indeterminate number), usually in 1 whorl, free, epipetalous or adnate to the calyx-tube, variously inserted in relation to the disk, when present; filaments usually subulate to ± filiform, sometimes very short; anthers 4-locular and dehiscing longitudinally or, rarely, multilocular and dehiscing by a large ventral valve (Rhizophora), dorsifixed, introrse

Morphology Reproductive morphology Flowers Gynoecium

Ovary syncarpous, (l)2–4(5)-locular, inferior to superior; placentae axile, each with usually 2 (1 in Anisophyllea) pendulous, anatropous ovules; style usually single or 4–5(8) (Anisophylle), ± persistent, with entire or ± lobed stigmas

Morphology Reproductive morphology Fruits

Fruit a berry, a drupe (Anisophyllea) or a dry, septicidally dehiscent, 2–4-loculed capsule (Cassipourea)

Morphology Reproductive morphology Seeds

Seeds 1 or more, sometimes arillate (Cassipourea), often viviparous (mangrove species); embryo straight or curved and often with green cotyledons; endosperm present or rarely absent (Anisophylled)