Actinidiaceae Engl. & Gilg

First published in Syllabus (ed. 9 & 10) 279. 1924 [6 Nov 1924] (1924)nom. cons.
This family is accepted

Descriptions

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

Distribution
Actinidiaceae is a family of three genera: Actinidia Lindl.(c. 30 species including the kiwi-fruit A. deliciosa (A.Chev.) C.F.Liang & A.R.Ferguson), Saurauia Willd. (c. 300 species) and Clematoclethra (Franch.) Maxim. (c. 25 species) distributed in tropical and temperate regions of Asia with the genus Saurauia also occurring in Central and South America. Saurauia is the only genus of Actinidiaceae found in New Guinea.
Ecology
Members of the family occur in lowland to montane environments on a variety of substrates and in both intact and disturbed vegetation.
Morphology General Habit
Trees, shrubs or lianas, dioecious, functionally dioecious or monoecious
Morphology General Indumentum
Indumentum simple or multicellular, often setose, raphides often present in flowering and vegetative parts
Morphology Leaves Stipules
Stipules absent or minute
Morphology Leaves
Leaves simple, alternate, margins toothed, indumentum usually present
Morphology Reproductive morphology Inflorescences
Inflorescences axillary, cauliflorous or ramiflorous and cymose, racemose, paniculate or fascicled
Morphology Reproductive morphology Flowers
Flowers actinomorphic, unisexual, functionally unisexual or bisexual; calyx (3–)5(–8)-merous, imbricate-quincuncial, sub-connate at base or free, persistent, shorter than corolla, persistent; corolla (3–)5(–9)-merous, imbricate, connate at base or free, white (rarely pink or red); stamens (10–)many, adnate to base of petals or not, sometimes connate at base, anthers versatile, dehiscing longitudinally or by apical pores; ovary superior, glabrous or hairy, syncarpous, (3–)5–many-locular, placentation axile, ovules 10–many per locule; styles (1–)3–5(–many), connate for all or part of their length or free, usually persistent
Morphology Reproductive morphology Fruits
Fruit a fleshy berry or capsule, glabrous or hairy
Morphology Reproductive morphology Seeds
Seeds many, not arillate, sometimes embedded in a mucilaginous pulp.
[TONG]

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
Shrubs to treelets, rarely trees, often climbing, with twining stems; plants monoecious or dioecious
Morphology Leaves
Leaves simple, alternate, estipulate, entire, margins always serrate to crenate, hispid hairs almost always present, especially on stems, inflorescences and petioles
Morphology Reproductive morphology Inflorescences
Inflorescence racemose or paniculate, bracteate
Morphology Reproductive morphology Flowers
Flowers showy, hermaphrodite (unisexual in Actinidia), actinomorphic, bracteolate, often drooping or facing downards; sepals usually (3-)5(-8), free; petals (3-)4-5(-8), white or cream-coloured, rarely pink; stamens many (more than 30), fused to inside of petals, anthers 2-locular; ovary superior, (3-) 5 (-7)-carpelate, multi-ovulate, placentation axile, ovary crowned by several stigmas.  Fruit a succulent, indehiscent berry, sometimes covered in stiff hairs; seeds very numerous, small, black, tear-shaped.
Note
Notes on delimitation: The Actinidiaceae fits within order Ericales, together with the Ericaceae and Clethraceae (APG II, 2003, Souza & Lorenzi 2005). Number of genera: 1. Saurauia Willd. - 280 species worldwide, of which nearly 50 occur in the Neotropics. 2. Actinidia L. - Actinidia deliciosa (A. Chev.) Liang & A.R. Ferg. is often cultivated for its edible fruit, the kiwi.
Diagnostic
Distinguishing characters (always present): Leaves with many pairs of veins, margins serrate. Flowers drooping, with indefinite number of stamens, showy, clustered in dense inflorescences. Ovary with many locules and multi-ovulate, crowned by several stigmas. Berry with many small seeds and fleshy pulp. Leaves alternate, simple, sometimes clustered together, almost always with long, hispid hairs. Berry sometimes hairy. Key differences from similar families: Resembles Clethraceae but flowers are more showy and fruit a berry.
Distribution
Saurauia occurs from Central Mexico to Bolivia but  is absent from Brazil, Argentina, Paraguay, Uruguay and Chile. In the Neotropics, the Actinidiaceae is represented by the native genus Saurauia (absent from Brasil) and by the cultivated Actinidiachinensis Planch., the kiwi fruit.
[NTK]

Sources

  • Herbarium Catalogue Specimens

  • 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
  • Neotropikey

    • 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-nc-sa/3.0
  • Trees of New Guinea

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