Achatocarpaceae Heimerl

This family is accepted.


Zappi, D. (2009). Neotropical Achatocarpaceae.


Shrubs, treelets or rarely trees, occasionally climbers , leaves deciduous and branches often armed; plants monoecious Leaves simple , alternate , estipulate, entire . Inflorescence axillary , racemose, few-flowered, bracteate, greenish. Flowers small, greenish, hermaphrodite , actinomorphic , sepals (= tepals) 5, petals absent; stamens 10+, anthers 2-locular; ovary superior , 2-carpelate, unilocular, placentation basal< /A> , uni-ovulate, styles two, horn-shaped. fleshy , one-seeded, translucent or white, with remnants of sepals attached when ripe; seeds black, testa shiny.

General Description
Notes on delimitation
  • The Achatocarpaceae has been treated as part of the Phytolaccaceae in the past, but now it stands alone as an independent family (APG II, 2003, Souza & Lorenzi 2005). 
  • Recent molecular studies using the markers rbcL and matK resolve Amaranthaceae-Chenopodiaceae as sister to the Achatocarpaceae (Kadereit et al. 2003, Cuénoud et al. 2002) and this evidence is supported by existing morphological data.
  • Endemic to the Neotropics. See above.
Number of genera

1. Achatocarpus L. - around 10 species distributed mostly in Central and Northwestern South America in dryland vegetation.2. Phaulothamnus - a single species, P. spinescens A. Gray, from Mexico and S. United States.

Distribution in the Neotropics
  • The Achatocarpaceae is a small family (2 genera, 10-11 species) all endemic to the Neotropics.
Distinguishing characters (always present)
  • Plants with alternate, simple, estipulate leaves with entire margins, often spiny.
  • Flowers small, unisexual, in axillary racemes.
  • Ovarysuperior, with one basalovule and two horn-shaped stigmas.
  • Sepals (= tepals) present, free< /A> ; petals absent.
Key differences from similar families
  • It differs from the Amaranthaceae s.l. in having fleshyfruit with translucent skin (vs. dry fruit with different projections, dispersed mostly by wind); the Phytolaccaceae have mostly bi-many-locular ovaries, while the Achatocarpaceae has a one-locular ovary with one ovule.
Other important characters
  • Leaves often succulent, fleshy, deciduous, drying black.
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.

Cuénoud, P., V. Savolainen, L.W. Chatrou, M. Powell, R.J. Grayer & M.W. Chase. 2002. Molecular phylogenetics of Caryophyllales based on nuclear 18S RDNA and plastid rbcL, atpB, and matK  DNA sequences. Amer. J. Bot. 89(1): 132-144.

Kadereit, G., Borsch, T., Weising, K. and Freitag, H.  2003. Phylogeny of Amaranthaceae and Chenopodiaceae and the Evolution of C3 Photosynthesis. Int. J. Pl. Sci. 164: 959-986.

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.

Achatocarpaceae Heimerl appears in other Kew resources:

First published in Nat. Pflanzenfam., ed. 2 [Engler & Prantl] 16c: 174. 1934 (1934)

Accepted by

  • APG IV (2016)

  • Kew Names and Taxonomic Backbone

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at and
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families.

  • Neotropikey

    Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.