Pamianthe peruviana

Pamianthe peruviana, also known as the giant Peruvian daffodil, is a species of epiphytic plant native to seasonally dry areas of Peru and Bolivia.

Vegetative characteristics
The perennial plants with bulbs produce 5-7 linear leaves with a prominent mid vein, which form a pseudo-stem of up to 30 cm in length. Each leaf may reach lengths of up to 50 cm and widths of 2–4 cm.

Generative characteristics
The bisexual, radially symmetrical flowers are intensely fragrant. They resemble the flowers of Pancratium. They are produced in groups of 2-4 flowers, which have a 12–25 cm long perianth tube with three nectariferous channels. These features could suggest moth pollination. The pedicel is 1.5–3 cm long. With 8 cm of length, the outer tepals are slightly longer than the 7 cm long staminal cup. The incurved stamens with dorsifixed anthers are inserted in deep notches of the staminal cup, or corona.

Generative reproduction
Pamianthe is presumed to be moth pollinated based on their floral morphology. Specifically sphingid moths come into question. The plant is self compatible. The fruit takes 12–15 months to mature. Rapid germination occurs under humid conditions at 16-21 °C. Seedlings reach maturity within four to five years.

Vegetative reproduction
Pamianthe peruviana can also reprocuce asexually through stolons.

Cytology
The diploid chromosome count of Pamianthe is 2n = 46.

Etymology
The generic name Pamianthe refers to Major Albert Pam. The specific epithet peruviana references this species origin in Peru.

History
Pam discovered the species in 1926 on a bulb collecting expedition in Peru. Other sources state he received bulbs from Peru in 1928. Pam, who introduced the species to horticulture, was a friend of the horticulturalist Edward Augustus Bowles (1865 - 1954), to whom he gave a Pamianthe peruviana specimen in the 1930s. He also donated Pamianthe peruviana to the Royal Botanic Gardens, Kew in 1937.

Habitat
It was found along streams in the warm to temperate northern region of Peru at elevations of 1800 m above sea level.

Taxon authorship
There is conflicting information on the taxon authorship of this species. One source claims it to be anonymous, whereas most give Otto Stapf as the taxon author. The type specimen, which was cultivated by Albert Pam in the United Kingdom, is associated with Stapf as the taxon author.

Role as type species
Pamianthe peruviana is the type species of the genus Pamianthe.

Synonym status of Pamianthe cardenasii
Despite being the same taxon, it has been reported that Pamianthe cardenasii were a bulbous geophyte, and Pamianthe peruviana were an epiphyte.

Phylogeny
Some degree of possible hybridization was identified between Pamianthe peruviana and Pamianthe ecollis. According to a molecular clock analysis, both species shared a common ancestor 18.22 million years ago. This means Pamianthe peruviana diverged in the early Miocene.

Conservation
It is presumed to be extinct in the wild. It is not known when it was last recorded. According to the Cambridge Botanic Garden the conservation status has not been evaluated. Under its synonym Pamianthe cardenasii Traub it has also been classified as not evaluated by the national herbarium of Bolivia in 2005.

Ex-situ conservation is ensured in several living collections, such as the living collection of the Gothenburg Botanical Garden, the Royal Botanic Garden Edinburgh Living Plant Collections, the Oxford Botanic Garden, as well as private collections.

Horticulture
Despite it being very rare in cultivation, it can be easily cultivated as a houseplant if kept in a well aerated substrate, because it is intolerant of waterlogged conditions, which rapidly induce root rot. Ideally, it should be cultivated under moderately bright, humid conditions at temperatures of 18-30 °C. Seeds can be sown all year round. The optimal time is March–August. The remaining months are less optimal. The germination temperature should not be below 20 °C. Pamianthe makes a good greenhouse or container display. It is also suitable as a long-lasting cut flower.