Eucrosia

Eucrosia
Flowers of Eucrosia bicolor
Scientific classification
Kingdom: Plantae
clade: Angiosperms
clade: Monocots
Order: Asparagales
Family: Amaryllidaceae
Subfamily: Amaryllidoideae
Genus: Eucrosia
Ker Gawl.[1]
Species

See text

Synonyms

Eucrosia is a genus of herbaceous, perennial and bulbous plants in the Amaryllis family (Amaryllidaceae, subfamily Amaryllidoideae[5]) distributed from Ecuador to Peru. The name is derived from the Greek eu, beautiful, and krossos, a fringe, referring to the long stamens.[6] The genus contains eight species. Phaedranassa and Rauhia are the genera most closely related to Eucrosia.[7]

Contents

Distribution and habitat

Three species are endemic to Ecuador and two to Peru; three additional, largely Ecuadorean, species are occasional in Peru. Eucrosia is primarily a xeric, lowland, floristic element, inhabiting seasonally dry vegetation of the lower, western slopes and Pacific coastal lowlands, with a single species adapted to montane rainforest understory (E. dodsonii).[7][8]

Description

All the members of the genus are bulbous. The leaves are deciduous, with characteristic long petioles and elliptical or ovate blades (laminae), up to 25 cm wide; they may or may not be present when the flowers are produced. The inflorescence is an umbel of 6–30 weakly to strongly zygomorphic flowers, tubular at the base, green, yellow or red in colour. The stamens hang downwards (i.e. are declinate) and have long filaments which in most species form a cup containing nectaries at the base. The most common somatic chromosome number is 2n = 46. The flowers are thought to be adapted for butterfly pollination, but a single report of hummingbird visitation is recorded for E. eucrosioides. The fruit is a capsule with three locules; the seeds are flattened and winged.[7][8]

In cultivation, all species except the rainforest dweller E. dobsonii can be grown in pots in gritty soil in good light, being kept warm and dry when the leaves wither, and watered when the flowers or leaves begin to grow again. E. dobsonii needs shadier conditions and a more open growing medium. Only E. bicolor is widely grown.[9]

Species

The list of Eucrosia species, with their complete scientific name and authority, and geographic distribution is given below.[10]

References

  1. ^ Bot. Reg. 3: t. 207 (1817).
  2. ^ Edwards's Bot. Reg. 28: 49 (1842).
  3. ^ Handb. Amaryll.: 105 (1888), nom. illeg.
  4. ^ Taxon 31: 555 (1982).
  5. ^ Stevens, P.F. (2001 onwards), Angiosperm Phylogeny Website: Asparagales: Amaryllidoideae, http://www.mobot.org/mobot/research/apweb/orders/asparagalesweb.htm#AllAma 
  6. ^ Grossi 2010, p. 239
  7. ^ a b c Meerow 1987
  8. ^ a b Grossi 2010, pp. 240–1
  9. ^ Grossi 2010, p. 241
  10. ^ Royal Botanical Gardens, Kew. World Checklist of Monocotyledons: Eucrosia. Accessed June 1, 2009.

Bibliography

External links