Climber or trailer with herbaceous shoots, large woody rootstock, and dioecious sex system. The leaves are simple, petiolate, with a more or less circular, finely dissected blade, the lobes 10 mm long and 2 mm broad. The tendrils are simple, filiform. The flowers small, male flowers in racemes, female flowers solitary. The receptacle-tube is subcylindrical with long-hairy throat and five dentiform sepals. The corolla is rotate with five subspathulate, 3.5-4 mm long, green petals. The three stamens are inserted near the mouth of the tube on free filaments. Two anthers are bithecous, one monothecous, coherent. The thecae are curved and contain tricolporate, reticulate pollen (Pozner 1998). The ovary is oblong, compressed, with two placentae. The style is elongate, c. 4 mm long with two stigmata. The fruit is 7-8 mm long, laterally compressed, glabrous, shortly rostrate, ripening red. The 4-8 seeds are pyriform, 5-5.5 by 2 by 1.5 mm. The testa is sculptured or rugose, slightly margined.
The only species grows in halophilous bushland on the border of salinas in Central Argentina.
Phylogenetically, Halosicyos is placed in the tribe Coniandreae but its exact position is still unresolved (Schaefer et al. 2009; Schaefer & Renner 2011).
Martínez Crovetto, R. 1947. Halosicyos, nuevo género de Cucurbitáceas de la flora argentina Bol. Soc. Argent. Bot. 2: 84-90.
Pozner, R. 1998. Cucurbitaceae. Flora Fanerogámica Argentina. Fascículo 53. 275. Proflora (Conicet), Córdoba: 58 pp.
Schaefer, H. and S.S. Renner. 2011. Phylogenetic relationships in the order Cucurbitales and a new classification of the gourd family (Cucurbitaceae). Taxon 60: 122-138.
Schaefer, H., Heibl, C., and S.S. Renner. 2009. Gourds afloat: a dated phylogeny reveals an Asian origin of the gourd family (Cucurbitaceae) and numerous oversea dispersal events. Proceedings of the Royal Society B 276: 843-851.