Anacardiaceae

Rhus L.

First published in Sp. Pl.: 265 (1753)
This genus is accepted
The native range of this genus is Eurasia, Canary Islands, NW. Africa, N. & Central America, Bahamas, Cuba.

Descriptions

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

Distribution
A genus of about species from the tropics, subtropics and temperate regions. Five species in New Guinea (four endemic), one species in the Solomon Islands.
Morphology General Habit
Deciduous trees and shrubs to 30 m (in New Guinea), sometimes scramblers or hemi-epiphytes, buttresses sometimes present
Morphology Leaves
Leaves spirally arranged, imparipinnate, trifoliolate or unifoliolate, petiolate, margins entire, pit-like domatia present
Morphology Reproductive morphology Inflorescences
Inflorescence axillary or (pseudo-)terminal, paniculate or thyrsoid, floral subtending bracts persistent or deciduous
Morphology Reproductive morphology Flowers
Flowers functionally unisexual or bisexual, 5-merous; calyx 5-lobed; petals 5, imbricate; stamens 5, imperfect or sterile in pistillate flowers; ovary 1-locular and 1-ovulate, reduced in staminate flowers; styles 3, often united basally, terminal in fruit
Morphology Reproductive morphology Fruits
Fruits a drupe, globose to obliquely subglobose and slightly compressed, mixed glandular pubescent and pilose, red at maturity; exocarp and mesocarp united; mesocarp glutinous, red
Morphology Reproductive morphology Seeds
Seed 1.
Ecology
Found in variety of habitats including primary lowland rain forest, sago swamps, savannah and reaching montane forest, but also in clearings and secondary forest; from sea level to 2400 m.
Recognition
The genus can be recognised by being always compound (including unifoliolate leaves), relatively short petioles (usually less than 0.5 cm), with pit-like domatia sometimes present on the leaf underside, with relatively smaller fruits which are obliquely subglobose having the style remnant terminal.
[TONG]

Anacardiaceae, Rosette Fernandes & A. Fernandes. Flora Zambesiaca 2:2. 1966

Morphology General Habit
Shrublets, suffrutices, shrubs or trees.
Morphology Leaves
Leaves alternate, simple, 3-foliolate or imparipinnate, rarely digitately 5-foliolate.
Morphology Reproductive morphology Inflorescences
Panicles terminal, axillary or both, ± branched.
Morphology Reproductive morphology Flowers
Flowers unisexual, exceptionally bisexual, very small. Male flowers: calyx (4)5(6)-partite, the segments imbricate; petals (4)5(6), longer than the calyx, imbricate; stamens 5; filaments subulate, inserted below the disk; anthers ovate, dorsifixed, introrse; disk patellifonn or cupuliform; pistillode usually absent. Female flowers: perianth similar to that of the male; staminodes frequently present; ovary ovoid to subglobose, usually 1-locular, with the ovule pendent from an ascendent funicle inserted at the base of the loculus; styles 3, apical, free or connate at the base; stigmas ± capitate.
Morphology Reproductive morphology Fruits
Drupe globose or ovoid and compressed, frequently asymmetrical, glabrous or hairy; mesocarp fleshy, ± resinous, sometimes ± dry; endocarp bony or crustaceous.
Morphology Reproductive morphology Seeds
Seed ovoid or reniform, compressed, with a thin testa; cotyledons very compressed.
[FZ]

Anacardiaceae, J. O. Kokwaro (University of Nairobi). Flora of Tropical East Africa. 1986

Morphology General Habit
Suffrutices, shrubs or trees
Morphology Leaves
Leaves alternate, simple, 3-foliolate or imparipinnate, rarely digitately 5-foliolate
Morphology Reproductive morphology Inflorescences
Inflorescences of terminal and/or axillary panicles
Morphology Reproductive morphology Flowers
Flowers unisexual, occasionally bisexual, very small Male flowers: calyx (4–)5(–6)-partite, segments imbricate; petals (4–)5(–6), longer than the calyx, imbricate; stamens 5, filaments subulate, inserted below the disk, anthers ovate, dorsifixed, introrse; disk saucer- or cup-shaped; pistillode usually absent Female flowers: perianth similar to ♂; staminodes frequently present; ovary ovoid to subglobose, usually unilocular, with the ovule pendent from an ascendent funicle inserted at the base of the locule; styles 3, apical, free or occasionally connate at the base; stigmas somewhat capitate
sex Male
Male flowers: calyx (4–)5(–6)-partite, segments imbricate; petals (4–)5(–6), longer than the calyx, imbricate; stamens 5, filaments subulate, inserted below the disk, anthers ovate, dorsifixed, introrse; disk saucer- or cup-shaped; pistillode usually absent
sex Female
Female flowers: perianth similar to ♂; staminodes frequently present; ovary ovoid to subglobose, usually unilocular, with the ovule pendent from an ascendent funicle inserted at the base of the locule; styles 3, apical, free or occasionally connate at the base; stigmas somewhat capitate
Morphology Reproductive morphology Fruits
Drupe globose or ovoid and compressed, frequently asymmetrical, glabrous or hairy; mesocarp fleshy, somewhat resinous, sometimes rather dry; endocarp bony or crustaceous
Morphology Reproductive morphology Seeds
Seed ovoid or reniform, compressed, with a thin testa; cotyledons very compressed.
[FTEA]

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Trees, shrubs or subshrubs, usually dioecious
Morphology Leaves
Leaves alternate, digitately 3-foliolate in Somalia, elsewhere sometimes simple or with more leaflets or imparipinnate
Morphology Reproductive morphology Inflorescences
Flowers in panicles, very small, usually 5-merous; petals longer than sepals
Morphology Reproductive morphology Flowers
Female flowers usually with staminodes; ovary usually glabrous and 1-celled; styles usually 3, free, stigmas ± capitate Male flowers with 5 stamens inserted below a prominent disk, usually without pistillode
Morphology Reproductive morphology Fruits
Drupes globose to kidney-shaped, glabrous in Somalia.
Distribution
Some 50-100 species in tropical and warm temperate regions.
[FSOM]

Sources

  • Flora Zambesiaca

    • Flora Zambesiaca
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Flora of Somalia

    • Flora of Somalia
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Herbarium Catalogue Specimens

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Trees of New Guinea

    • Trees of New Guinea
    • http://creativecommons.org/licenses/by-nc-sa/3.0