Contributor

Daniela Zappi

Address

Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK

Description

Trees, shrubs or herbs, sometimes epiphytes, with three distinct types of branch: normal vegetative branch, areoles (reduced branches that can originate stems, spines or flowering branches) and flowering branches. Developed leaves present in one subfamily (Pereskioideae), reduced leaves present in Opuntioideae, Cactoideae devoided of leaves. Branches green, photosynthetic, succulent, ribs and tubercles present. Spines organized within areoles, together with hairs and bristles, specialized serreated spines and glochid present only in Opuntioideae. Flowers generally showy, epigynous, with receptacular inferior ovary, solitary or in inflorescences, externally with areoles, bracts and many perianth segments arranged spirally and showing a transition between sepaloid (external) and petaloid (internal) segments, flower tube generally developed, nectar chamber above the ovary and basal region of the tube, stamens numerous, filaments fleshy; ovary unilocular, originated from the fusion of many carpels (generally number of carpels reflected on the number of stigma lobes). Fruits berry-like, fleshy, multisseminated, indehiscent or dehiscent, seeds cochleariform, with bone-like testa in Opuntioideae, testa dark and normally shiny in Pereskoideae and Cactoideae.

Notes on delimitation

DNA studies show that Portulacaceae possibly cannot be separated from Cactaceae because it lacks autoapomorphies; Cactaceae however presents areoles and they are not present as such in Portulacaceae.

Distribution in Neotropics

Distribution Neotropical with the exception of one species, Rhipsalis baccifera distributed in the Old World.

Top

Distinguishing characters (always present)

Presence of three types of branches: vegetative expanded branches, reduced, stucture bearing branches called areoles (specific to the family), flowering branches; receptacular inferior ovary, spines (sometimes lacking or profoundly modified)

Other important characters

Succulence, spines, many perianth transitional segments (sepals and petals)

Key differences from similar families

Rarely present latex (diff from succulent Euphorbiaceae); spines are produced in areoles (different from other stem succulents like Asclepiadaceae, Euphorbiaceae, etc.).

Number of genera

124 genera, over 1300 species

Cactaceae
Family index \| Glossary
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Contributor Address Description Notes on delimitation Distribution in Neotropics Distinguishing characters (always present) Other important characters Key differences from similar families Number of genera	Contributor Daniela Zappi Address Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK Description Trees, shrubs or herbs, sometimes epiphytes, with three distinct types of branch: normal vegetative branch, areoles (reduced branches that can originate stems, spines or flowering branches) and flowering branches. Developed leaves present in one subfamily (Pereskioideae), reduced leaves present in Opuntioideae, Cactoideae devoided of leaves. Branches green, photosynthetic, succulent, ribs and tubercles present. Spines organized within areoles, together with hairs and bristles, specialized serreated spines and glochid present only in Opuntioideae. Flowers generally showy, epigynous, with receptacular inferior ovary, solitary or in inflorescences, externally with areoles, bracts and many perianth segments arranged spirally and showing a transition between sepaloid (external) and petaloid (internal) segments, flower tube generally developed, nectar chamber above the ovary and basal region of the tube, stamens numerous, filaments fleshy; ovary unilocular, originated from the fusion of many carpels (generally number of carpels reflected on the number of stigma lobes). Fruits berry-like, fleshy, multisseminated, indehiscent or dehiscent, seeds cochleariform, with bone-like testa in Opuntioideae, testa dark and normally shiny in Pereskoideae and Cactoideae. Notes on delimitation DNA studies show that Portulacaceae possibly cannot be separated from Cactaceae because it lacks autoapomorphies; Cactaceae however presents areoles and they are not present as such in Portulacaceae. Distribution in Neotropics Distribution Neotropical with the exception of one species, Rhipsalis baccifera distributed in the Old World. Top Distinguishing characters (always present) Presence of three types of branches: vegetative expanded branches, reduced, stucture bearing branches called areoles (specific to the family), flowering branches; receptacular inferior ovary, spines (sometimes lacking or profoundly modified) Other important characters Succulence, spines, many perianth transitional segments (sepals and petals) Key differences from similar families Rarely present latex (diff from succulent Euphorbiaceae); spines are produced in areoles (different from other stem succulents like Asclepiadaceae, Euphorbiaceae, etc.). Number of genera 124 genera, over 1300 species
Copyright Neotropikey: Royal Botanic Gardens, Kew