Saxifragaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:1. 1954
- Morphology General Habit
- Herbs, not or slightly succulent
- Morphology Leaves
- Leaves usually alternate (opposite in Vahlia), exstipulate
- Morphology Reproductive morphology Flowers
- Flowers actinomorphic, hermaphrodite, rarely solitary
- Morphology Reproductive morphology Flowers Calyx
- Sepals usually 5, imbricate or valvate
- Morphology Reproductive morphology Flowers Corolla
- Petals alternate with the sepals or absent, often clawed, perigynous or rarely epigynous
- Morphology Reproductive morphology Flowers Androecium
- Stamens inserted with the petals, 5–10; filaments free; anthers 2-celled, dehiscing longitudinally
- Morphology Reproductive morphology Flowers Gynoecium
- Ovary 1–5-celled, free or adnate to the receptacle; styles usually free; ovules numerous, on axile or parietal placentas or the latter pendulous from the apex of the cells
- Morphology Reproductive morphology Fruits
- Fruit a capsule
- Morphology Reproductive morphology Seeds
- Seeds usually numerous, small, with endosperm; embryo minute, straight
- Widely distributed in temperate regions, rare in the tropics
Zappi, D. (2009). Neotropical Saxifragaceae.
Perennial herbs, often growing together and forming mats. Leaves simple , alternate and basal , rosulate, or rarely opposite, without stipules (stipules sometimes represented by expanded margins of sheathing petiolar leaf bases), entire or deeply lobed to rarely compound , margin often crenate , venation pinnate or often palmate . Inflorescence axillary to terminal , racemose or cymose, bracteate. Flowers showy, hermaphrodite , actinomorphic , rarely zygomorphic , bracteolate; sepals (3-)5, free ; petals (3-)5, often clawed and dissected , white or cream-coloured, rarely pink; stamens 3-10, free , anthers 2-locular; intrastaminal disk present, ovary inferior to superior , 2(-3) carpelate, carpels connate towards base forming a compound , deeply lobed ovary , lobes prolonged into stylar beaks terminated by a capitate stigma , placentation variously axile and parietal , ovules numerous. Fruit capsular, dry, septicidal or dehiscing along ventral suture of carpels above level of union; seeds numerous, small.
- General Description
Notes on delimitation
- In former classifications, the Saxifragaceae used to include not only herbaceous but also woody genera that are nowadays included in other families (Escalloniaceae, Hydrangeaceae, Grossulariaceae). The present circumscription stems from molecular studies that support the Saxifragaceae s.s. (APG II, 2003, Soltis in Smith et al. 2004).
- The few genera present in the Neotropics are associated with highlands, and there are a few cultivated species of Heuchera from Mexico, but this is not expressive in the tropics and does not naturalize. Endemic genera are Tetilla, which occurs only in Chile, and Jepsonia in California reaching Baja California.
Six genera (See Distribution) of which Tetilla is not strictly Neotropical.
Distribution in the Neotropics
- In the Neotropics, the Saxifragaceae is quite a marginal family with a few genera occurring at high altitude and reaching Mexico from the West of the USA.
- Heuchera L. - widespread through North America to C. Mexico, 5-6 species.
- Jepsonia Small - endemic to California and Baja California, 2-3 species.
- Saxifraga L. - North temperate regions of the world, in America it occurs in Mexico and in the Andes to Cape Horn and Falkland Islands, 6-7 species.
- Hieronymusiaalchemilloides (Griseb.) Engler - monospecific, formerly placed in Suksdorfia, North America into N. California; Andes of S. Bolivia and NW Argentina.
- Tetillahydrocotylifolia DC. - monospecific, Chile.
Other important characters
- Intra-staminal nectar disk.
- Carpels projected into stylar beaks terminated by capitatestigma.
- Perennial herbs.
- Leaves mostly rosulate, margin crenate or lobed.
- Flowers 5-merous, petals clawed and often fimbriate.
- Ovary inferior to superior generally with 2 carpels not fused to the top.
- Fruits capsular with many seeds.
- Vegetatively resembles the Gentianaceae, Apiaceae, Violaceae and other alpine plants found in the Andes, being distinguished from them by its corolla with five distinct petals, stamens 1 or 2 x the number of petals.
- It can be confused with the Crassulaceae, but these are succulent and have carpels totally distinct and generally present in larger number (4 or +).
APG II, 2003. An update of the Angiosperm Phylogeny group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society 141(4): 399-436.
Soltis, D.E. 2004. Saxifragaceae, pp. 346-348. In: Smith, N., Mori, S.A., Henderson, A., Stevenson, D. and Heald, S.V. (eds.). Flowering Plants of the Neotropics. New York Botanical Garden, Princeton University Press, Princeton.
Flora of West Tropical Africa
- Flora of West Tropical Africa
Kew Names and Taxonomic Backbone
- The International Plant Names Index and World Checklist of Vascular Plants 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
- © Copyright 2022 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
- Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.