Nematanthus is a genus of flowering plants in the family Gesneriaceae. All of its species are endemic to Brazil. Compared to other gesneriads, Nematanthus has leaves that are small, succulent, and hard-surfaced. The plant has a trailing, branching, and spreading habit; it is generally an epiphyte in nature and a hanging-basket plant in cultivation. The flower has fused petals. In some species, the flower has a "pouch" at the bottom. The fancied resemblance of such flowers to a goldfish gives these plants the common name goldfish plant or guppy plant.
Hummingbirds will often feed from the nectar-filled "goldfish" flowers.
Description
Nematanthus species are perennials or subshrubs, typically growing epiphytically, less often in humus-filled pockets on rocks. Their leaves are often reddish underneath. Their flowers have fused petals and vary quite widely in shape. Some have flowers with a "pouch" on the lower surface of the flower and a small opening (particularly those commonly cultivated). Others have flowers that are twisted through 180° when fully open (resupinate), so that if pouched, the pouch is at the top. Resupinate flowers may be brightly coloured, funnel-shaped and compressed from side to side, or white and bell-shaped. Some species have flowers that are borne on long pedicels and hang down below the plant, others have short pedicels so that the flowers are close to the stem.
Taxonomy
The genus Nematanthus was first described by Heinrich Adolph Schrader in 1821, with the only species (and so the type species) being Nematanthus corticola, one of the species with flowers hanging down on long pedicels. The name Nematanthus is from Ancient Greek nema meaning 'thread' and anthos meaning 'flower', referring to the 20 cm (8 in) long pedicels of the type species.
Nematanthus is placed in the subfamily Gesnerioideae, tribe Gesnerieae, subtribe Columneinae. Within the subtribe, it forms a clade with Codonanthe, Codonanthopsis and Lesia:
