''Eucrosia'' is a genus of

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of ...

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

and

bulbous plants Bulb or Bulbs may refer to: Common uses * Bulb, a food-storage structure within some plants ** Ornamental bulbous plant, Ornamental bulb, a kind of perennial plant * Light bulb, an electric lamp Maritime * Bulb keel, a type of keel * Bulbous b ...

in the Amaryllis family (

Amaryllidaceae The Amaryllidaceae are a family of herbaceous, mainly perennial and bulbous (rarely rhizomatous) flowering plants in the monocot order Asparagales. The family takes its name from the genus '' Amaryllis'' and is commonly known as the amaryl ...

, subfamily

Amaryllidoideae Amaryllidoideae (Amaryllidaceae ''s.s.'', amaryllids) is a subfamily of monocot flowering plants in the Family (biology), family Amaryllidaceae, Order (biology), order Asparagales. The most recent Angiosperm Phylogeny Group, APG classification, A ...

) distributed from

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

. The name is derived from the Greek , beautiful, and , a fringe, referring to the long stamens. As

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

in 2020, the genus contains six species. '' Phaedranassa'' and '' Rauhia'' are the genera most closely related to ''Eucrosia''.

Description

All the members of the genus are

bulb In botany, a bulb is a short underground stem with fleshy leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food storage organs duri ...

ous. The leaves are

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

, 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 In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is an

umbel UMBEL (Upper Mapping and Binding Exchange Layer) is a logically organized knowledge graph of 34,000 concepts and entity types that can be used in information science for relating information from disparate sources to one another. It was retired ...

of 6–30 weakly to strongly

zygomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spir ...

flowers, tubular at the base, green, yellow or red in colour. The

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s hang downwards (i.e. are declinate) and have long filaments which in most species form a cup containing

nectaries Nectar is a viscous, sugar-rich liquid produced by plants in glands called nectaries, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, ...

at the base. The flowers are assumed to be adapted for

butterfly Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...

pollination, although there is one report of a

hummingbird Hummingbirds are birds native to the Americas and comprise the Family (biology), biological family Trochilidae. With approximately 366 species and 113 genus, genera, they occur from Alaska to Tierra del Fuego, but most species are found in Cen ...

visiting ''E. eucrosioides''. The fruit is a capsule with three

locule A locule (: locules) or loculus (; : loculi) is a small cavity or compartment within an organ or part of an organism (animal, plant, or fungus). In angiosperms (flowering plants), the term ''locule'' usually refers to a chamber within an ovary ...

s; the seeds are flattened and winged. The diploid chromosome number is most commonly 2''n''=46.

Taxonomy

It was published by

John Bellenden Ker Gawler John Bellenden Ker ( ''Gawler'') was an English botanist, born about 1764, Ramridge, Andover, Hampshire, which was where he died in June 1842. On 5 November 1804, he changed his name to Ker Bellenden, but continued to sign his name as Bellende ...

in 1817 with '' Eucrosia bicolor'' as the type species.

Species

, the

World Checklist of Selected Plant Families The World Checklist of Selected Plant Families (usually abbreviated to WCSP) was an "international collaborative programme that provides the latest peer reviewed and published opinions on the accepted scientific names and synonyms of selected p ...

accepted seven species of ''Eucrosia''. One, ''E. dodsonii'', has since been recognized as belonging to the genus '' Urceolina'' and transferred as '' Urceolina dodsonii''. *'' Eucrosia aurantiaca'' (Baker) Traub – Southern central Ecuador *'' Eucrosia bicolor'' Ker Gawl. – Ecuador to Peru *'' Eucrosia calendulina'' Meerow & Sagást. – Peru *'' Eucrosia eucrosioides'' (Herb.) Pax – South western Ecuador to Northern Peru *'' Eucrosia mirabilis'' (Baker) Traub – Peru, Ecuador *'' Eucrosia stricklandii'' (Baker) Meerow – Ecuador A formerly accepted species has been moved to the genus ''

Stenomesson ''Stenomesson'' is a genus of bulbous plants in the family Amaryllidaceae. All the species are native to western South America (Colombia, Ecuador, Peru and northern Chile).Meerow, Alan W. 2000. Phylogeny of the American Amaryllidaceae based on nr ...

'': *''Eucrosia tubiflora'' Meerow = '' Stenomesson tubiflorum'' (Meerow) Meerow

Distribution and habitat

''Eucrosia'' is restricted to the central

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

of Ecuador and Peru. All of the species are found only in small areas or as small numbers of individuals. Two species are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to Ecuador, one to Peru. Three further species are only occasionally found in Peru, being primarily distributed in Ecuador. All species of ''Eucrosia'' are adapted to seasonally dry habitats, found on the lower, Pacific-facing slopes of the Andes and the adjacent lowlands.

Cultivation

In cultivation, all species 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. Only ''E. bicolor'' is widely grown. ''Eucrosia'' has been successfully used in intergeneric hybridisation with '' Rauhia''.Meerow, A. W., Roh, M., & Lawson, R. S. (1992, May)
Breeding of ''Eucrosia'' (Amaryllidaceae) for cutflower and pot plant production.
In VI International Symposium on Flower Bulbs 325 (pp. 555-560).

References

Bibliography

* * *

External links

Images of ''Eucrosia'' species
fro
The International Bulb Society website
{{Taxonbar, from=Q5406295 Amaryllidaceae genera Taxonomy articles created by Polbot