The Families of Flowering Plants
The Families of Flowering Plants | |
~ Portulacaceae
Habit and leaf form. Herbs; non-laticiferous and without coloured juice. Densely caespitose, perennial. Leaves small; alternate; leathery; densely imbricate; simple. Lamina entire. Leaves exstipulate. Lamina margins entire.
Stem anatomy. Secondary thickening absent, or developing from a conventional cambial ring (?). Sieve-tube plastids P-type; type III (a).
Reproductive type, pollination. Plants polygamomonoecious (?).
Inflorescence, floral, fruit and seed morphology. Flowers solitary; axillary; bracteolate (with 2–3 bracteoles), or ebracteolate; regular. Free hypanthium absent.
Perianth with distinct calyx and corolla, or sepaline (since postulated relationship with Portulacaceae implies that the ‘sepals’ represent modified bracteoles, the ‘corolla’ a petaloid calyx); 6, or 7; 1 whorled, or 2 whorled (as interpreted here); anisomerous. Calyx 2 (anterior/posterior); 1 whorled; polysepalous; persistent; median. Corolla 4–5; polypetalous, or gamopetalous (then shortly connate). Corolla lobes markedly longer than the tube.
Androecium 3–5(–6). Androecial members free of the perianth, or adnate (to the corolla tube, when this present); free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 3–5(–6); reduced in number relative to the adjacent perianth, or isomerous with the perianth; oppositisepalous (alternating with the petals, by contrast with Portulacaceae). Anthers versatile. Pollen grains aperturate; 3 aperturate; colporate.
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary 1 locular. Gynoecium stylate. Styles 1; apical. Stigmas 1–2. Placentation free central (the ovules borne near the base). Ovules in the single cavity 4–7.
Fruit non-fleshy; dehiscent; a capsule; 1–5 seeded. Seeds endospermic (unless the ‘endosperm’ is perisperm, cf. Portulacaceae). Perisperm present, or absent (?). Embryo well differentiated. Embryo curved.
Geography, cytology. Antarctic. Frigid zone (Antarctic), or temperate. New Zealand, Kerguelen Is.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Caryophylliflorae; Caryophyllales. Cronquist’s Subclass Caryophyllidae; Caryophyllales. APG 3 core angiosperms; core eudicot; Superorder Caryophyllanae; Order Caryophyllales (as a synonym of Portulacaceae).
Species 2. Genera 2; Hectorella, Lyallia.
Philipson and Skipworth (1961).
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, geographical distribution, genera included in each family, classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG), and notes on the APG classification.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 25th November 2009. http://delta-intkey.com’.