Herbaceous plants with a ± tuberous rhizome or a corm, often carrying fibrous remains of former leaves. Leaves basal, 1-many, rosulate and 3ranked, with a more or less sheathing base, sessile or with a distinct pseudopetiole (in Curculigo, Hypoxidia and Molineria), outermost leaves often reduced to cataphylls, lamina linear to lanceolate, pubescent with simple and compound hairs, sometimes glabrous; the lamina prominently parallel-veined, often V-shaped in cross-section, sometimes plicate (mainly in the pseudopetiolate taxa), rarely terete. Inflorescences usually on hairy scapes, often several per plant, arising from leaf axils, spicate to corymbose or umbel-like, sometimes reduced to solitary flowers. Flowers most often pedicellate, sometimes sessile, from the axils of small or larger and leafy braets (Curculigo, Molineria), hermaphroditic (rarely unisexual in Curculigo), actinomorphic. Tepals 3 + 3 (rarely 2 + 2 in Hypoxis and Spiloxene), ± persistent, subequal, free (in most genera) or fused to form a tube (in Hypoxidia, Pauridia, Rhodohypoxis, Saniellia), most often yellow to orange, sometimes reddish, pinkish or white (Rhodohypoxis and Pauridia) or reddish brown (Hypoxidia), often green and pubescent abaxially. Stamens 3 + 3 (2 + 2), most often uniseriate, biseriate in Rhodohypoxis and Hypoxidia), or only 3, then opposite the inner tepals (Pauridia); filaments short to almost lacking, arising from the base of perianth segments or from the mouth of the perianth tube; anthers elongate, basifixed or (low) dorsifixed, slightly versatile or not, opening introrsely or latrorsely by longitudinal slits, in some cases with apical appendages. Ovary inferior, trilocular with axile placentation or unilocular with 3 parietal placentas (Empodium), transitional forms found in Hypoxidea and some species of Spiloxene with trilocular lower part merging to unilocular upper part, ovary often prolonged upwards into an epigynous beak (Curculigo, Empodium, Saniellia). Style 1, short with 3(6) stigmas either as free lobes or as groves along the style. Ovules often numerous, sometimes only few. Fruit a capsule with circumscissile or loculicidal dehiscence, or sometimes more or less fleshy and indehiscent or irregularly dehiscent, often beaked. Seeds with a thick phytomelan crust, globose to ellipsoid, with a more or less protuding micropyle, and a more or less prominent funicle, sometimes with a prominent strophiole (Curculigo, Empodium); testa most often black, sometimes brownish, glossy or dull, smooth to papillate or verrucose; embryo small; endosperm copious, non-farinaceaous.
Nine genera and about 100 species (a very approximate number, as one of the genera, Hypoxis, is largely apomictic, accordingly with problematic species delimitation); widely distributed in tropical and subtropical regions of all continents particularly of the southern hemisphere, transgressing slightly into the northern hemisphere on all continents, but particularly in America.
Nordal, I., Kubitzki, K., 1998. Hypoxidaceae With kind permission from Springer Science+Business Media: This work is subject to copyright. All rights reserved, whether whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, broadcasting reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under German Copyright Law.