''Stenomesson leucanthum'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

in the 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 ...

. It is native to

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

Pierfelice Ravenna Pierfelice (Pedro Félix, Pierre Félice) Ravenna (born 1938) is a Chilean botanist of Italian Jewish origin. His research interests are mainly in the field of South American Amaryllidaceae.Ravenna P. 1974 Pierfelice Ravenna: an autobiography. Pl ...

the Chilean botanists who first formally described the species, using the

basionym In the scientific name of organisms, basionym or basyonym means the original name on which a new name is based; the author citation of the new name should include the authors of the basionym in parentheses. The term "basionym" is used in both bota ...

''Pucara leucantha'', named it after its white (Latinized form of Greek , leukós) flowers (Latinized form of Greek , ánthos).

Description

It is a

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicina ...

with a round bulb that is 3.7-4.8 centimeters in diameter. Its leaves are often solitary and are 10-12 by 2-3 centimeters with pointed tips. Its

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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...

s are on a stem-like stalk that is 15-50 centimeters long. The flowering stalk is 5 millimeters at its apex. The flowering stalk is circular in cross section. Its flowers occur in clusters at the top of the stalk. The cluster of flowers is subtended by narrow, papery bracts that are 2.5-3.1 centimeters long and come to a point at their tips. Each flower is on a 3-6 millimeter long

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

. The white, bell-shaped flowers are 1.2-1.4 centimeters in diameter. Atop the floral tube are 6

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s arranged in two rows. The elliptical outer tepals are 12-14 by 4 millimeters and come to a point at their tip. The elliptical inner tepals are 14 by 5 millimeters. Its

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

are 3.6-5.8 millimeters long. Its flowers have a single thread-like

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

that is 1.9-2 centimeters long and topped by a 3-lobed stigma. Its flowers have an ellipsoid ovary that is 3.8-4 by 1.5-2 millimeters with 3 chambers. Its fruit are round.

Distribution and habitat

It grows in northern Peru on rocky slopes and sandy places at elevations of 990-1,650 meters above sea level.

Reproductive biology

The yellow pollen of ''S. leucanthum'' is shed as permanent tetrads.

References

{{Taxonbar, from=Q15504946 Amaryllidoideae Endemic flora of Peru Species described in 2004 Taxa named by Alan Meerow