Actinidiaceae Engl. & Gilg

Zappi, D. (2009). Neotropical Actinidiaceae.

Morphology

Description

Shrubs to treelets, rarely trees, often climbing, with twining stems; plants monoecious or dioecious . Leaves simple , alternate , estipulate, entire , margins always serrate to crenate , hispid hairs almost always present, especially on stems, inflorescences and petioles. Inflorescence racemose or paniculate, bracteate. 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.

Distribution

Distribution in the Neotropics

• In the Neotropics, the Actinidiaceae is represented by the native genus Saurauia (absent from Brasil) and by the cultivated Actinidiachinensis Planch., the kiwi fruit.

Diagnostic

Other important characters

• Leaves alternate, simple, sometimes clustered together, almost always with long, hispid hairs.
• Berry sometimes hairy.

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.

Key differences from similar families

• Resembles Clethraceae but flowers are more showy and fruit a berry.

General Description

Status

• Saurauia occurs from Central Mexico to Bolivia but  is absent from Brazil, Argentina, Paraguay, Uruguay and Chile.

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.

Literature

Important literature

APG II, 2003. An update of the Angiosperm Phylogeny group classification for the orders and families of flowering plants: APG II. Bot. J. Linn. Soc. 141(4): 399-436.

Soejarto, D.D. 1980. Revision of South American Saurauia (Actinidiaceae). Fieldiana (Botany), new series 2: 1-141.

Souza, V.C. & Lorenzi, H. 2005. Botânica Sistemática: guia ilustrativo para identificação das famílias de Angiospermas da flora brasileira, baseado em APG II. Nova Odessa, Brazil: Instituto Plantarum.