Spiloxene is a relatively uniform group of small, deciduous plants which seldom reach a height of 500 mm. The rootstock is a corm which is replaced annually after each growing season. Most often the desiccated corms of the previous seasons persist for a year or more in a vertical series. Exceptions are S. alba and S. aquatica where the corms are arranged almost horizontally.

The various corm coverings are sufficiently diagnostic to allow Spiloxene species to be placed in fairly easily recognisable groups. Species with thin-textured and finely-veined leaves usually have thin, membranous corm coverings, but, if the leaves are firm and coarsely veined, then the corm tunics are fibrous. When the fibres are branched, they form a fine, closely woven net over the corm, but when they are hard and straight, they resemble the teeth of a comb.

All Spiloxene species have contractile roots at some stage of their development. These regulate the depth of the corm in the ground and help to optimise the plant's growth. Remarkably, the roots of S. ovata and S. gracilipes twist around the corm and persist from one year to the next as a dense covering of hard, coiled roots. This nongeotropic growth pattern has seldom been reported in other geophytic plants and appears to be unique within Spiloxene.

Commencing in late autumn, the foliage grows into a basal tuft of more or less three-ranked leaves. These vary from narrowly lance-shaped to cylindrical or linear. Spiloxene aquatica, which inhabits seasonal pools, is exceptional in having somewhat hollow leaves, largely filled with air spaces. Unlike their well known relatives, Hypoxis and Rhodohypoxis, plants of Spiloxene are entirely smooth, except for a few species that have inconspicuous, shortly branched hairs on the leaf margins.

Each inflorescence consists of a slender, leafless scape which terminates in a few, often inconspicuous bracts and one or two (rarely up to seven) flowers with long, slender pedicels. As is typical in the family Hypoxidaceae, the flowers have six tepals, six stamens, a three-chambered, inferior ovary, and a three-branched style. Flowers are uniformly star-shaped and mostly golden or pale yellow in colour, but in a few species they are white and rarely pink. Distinct red and green stripes often line the backs of the outer tepals in species such as S. capensis and S. canaliculata.  However, most often the backs of the outer tepals are plain reddish pink or green. The largest and most striking flowers are those of S. capensis and S. canaliculata which also have dark spots or 'eyes' at the base of the tepals. In S. capensis the spots are generally blackish and occasionally iridescent blue-green, whereas those in S. canaliculata are deep, matt purple.

Spiloxene species are predominantly spring-flowering and, since they produce a succession of inflorescences each season, they continue to flower for a month or more. Generally they are sun-loving, so the flowers remain closed if conditions are cold or wet, often for several days at a time, until the weather improves. Even on warm days the flowers open for only a few hours, usually between 11am and 4 pm.

The seeds are produced in capsules that open when the spent floral parts drop off. When shaken, the capsules drop their seeds directly on the ground from where they may be washed away to other sites. The seeds are unusually tiny (0.4-1.0 mm long) and have a distinctively sculptured, dark brown, brittle coat.