Eucrosia
Encyclopedia
Eucrosia is a genus of herbaceous
, perennial and bulbous plants in the Amaryllis family (Amaryllidaceae
, subfamily Amaryllidoideae) distributed from Ecuador
to Peru
. The name is derived from the Greek eu, beautiful, and krossos, a fringe, referring to the long stamens. The genus contains eight species. Phaedranassa
and Rauhia are the genera most closely related to Eucrosia.
understory (E. dodsonii).
ous. 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 stamen
s 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 locule
s; the seeds are flattened and winged.
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.
Herbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
, perennial and bulbous plants in the Amaryllis family (Amaryllidaceae
Amaryllidaceae
Amaryllidoideae is the subfamily of flowering plants that takes its name from the genus Amaryllis. It is part of the family Amaryllidaceae, in order Asparagales...
, subfamily Amaryllidoideae) distributed from Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
to Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
. The name is derived from the Greek eu, beautiful, and krossos, a fringe, referring to the long stamens. The genus contains eight species. Phaedranassa
Phaedranassa
Phaedranassa is a genus of plant in family Amaryllidaceae, subfamily Amaryllidoideae. It contains the following species :* Phaedranassa brevifolia, Meerow* Phaedranassa cinerea, Ravenna...
and Rauhia are the genera most closely related to Eucrosia.
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 rainforestCloud forest
A cloud forest, also called a fog forest, is a generally tropical or subtropical evergreen montane moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests often exhibit an abundance of mosses covering the ground and...
understory (E. dodsonii).
Description
All the members of the genus are bulbBulb
A bulb is a short stem with fleshy leaves or leaf bases. The leaves often function as food storage organs during dormancy.A bulb's leaf bases, known as scales, generally do not support leaves, but contain food reserves to enable the plant to survive adverse conditions. At the center of the bulb is...
ous. The leaves are deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
, with characteristic long petioles
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
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
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is an umbel
Umbel
An umbel is an inflorescence which consists of a number of short flower stalks which are equal in length and spread from a common point, somewhat like umbrella ribs....
of 6–30 weakly to strongly zygomorphic flowers, tubular at the base, green, yellow or red in colour. The stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s 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
Butterfly
A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...
pollination, but a single report of hummingbird
Hummingbird
Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...
visitation is recorded for E. eucrosioides. The fruit is a capsule with three locule
Locule
A locule is a small cavity or compartment within an organ or part of an organism ....
s; the seeds are flattened and winged.
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.
Species
The list of Eucrosia species, with their complete scientific name and authority, and geographic distribution is given below.- Eucrosia aurantiacaEucrosia aurantiacaEucrosia aurantiaca is a species of plant which is endemic to Ecuador. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrubland. It is threatened by habitat loss....
(Baker) Traub, Pl. Life 22: 62 (1966). Southern central Ecuador. - Eucrosia bicolorEucrosia bicolorEucrosia bicolor is a species of plant found in Ecuador and Peru. Its natural habitats are seasonally dry lowland areas. It was the first species of Eucrosia to be scientifically described, in 1816, and the first to be introduced into cultivation in Europe, flowering outside its homeland for the...
Ker Gawl., Bot. Reg. 3: t. 207 (1817). Ecuador to Peru. - Eucrosia calendulinaEucrosia calendulinaEucrosia calendulina is a species of plant that is endemic to Peru.All members of the genus Eucrosia grow from bulbs and have stalked leaves with wide blades . The zygomorphic flowers are produced in an umbel. The stamens have prominent long filaments.E. calendulina is known only from the lower...
MeerowAlan W. MeerowAlan W. Meerow is an American botanist, born in New York in 1952. He specializes in the taxonomy of the family Amaryllidaceae and the horticulture of palms and tropical ornamental plants....
& Sagást., Sida 17: 761 (1997). Peru. - Eucrosia dodsoniiEucrosia dodsoniiEucrosia dodsonii is a species of plant that is endemic to Ecuador. Its natural habitat is subtropical or tropical moist montanes. It is threatened by habitat loss....
Meerow & Dehgan, Brittonia 37: 47 (1985). Ecuador. - Eucrosia eucrosioidesEucrosia eucrosioidesEucrosia eucrosioides is a species of plant that is found in south west Ecuador and north Peru. Its natural habitats are seasonally dry lowland areas....
(Herb.) Pax in H.G.A.Engler & K.A.E.Prantl (eds.), Nat. Pflanzenfam. 2(5): 115 (1887). South western Ecuador to Northern Peru. - Eucrosia mirabilisEucrosia mirabilisEucrosia mirabilis is a species of plant, found in Peru, from where it was originally scientifically described in 1869, and Ecuador, where it was rediscovered in 1997. Its natural habitats are seasonally dry lowland areas....
(Baker) Traub, Pl. Life 22: 62 (1966). Peru, Ecuador. - Eucrosia stricklandiiEucrosia stricklandiiEucrosia stricklandii is a species of plant which is endemic to Ecuador. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrubland. It is threatened by habitat loss....
(Baker) Meerow, Phytologia 58: 499 (1985). Ecuador. - Eucrosia tubifloraEucrosia tubifloraEucrosia tubiflora is a species of plant which is endemic to Peru.All members of the genus Eucrosia grow from bulbs and have stalked leaves with wide blades . The zygomorphic flowers are produced in an umbel. The stamens have prominent long filaments.E...
Meerow, Brittonia 37: 305 (1985). Peru.