''Costera'' is a genus in the

Ericaceae The Ericaceae () are a Family (biology), family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with about 4,250 known species spread acros ...

found in the

Malesian Malesia is a biogeographical region straddling the Equator and the boundaries of the Indomalayan and Australasian realms. It is a phytogeographical floristic region in the Paleotropical kingdom. It was first recognized as a distinct region in ...

floristic region. It is a small genus of often

epiphytic An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...

shrubs A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

that grows in tropical rainforests.

Description

''Costera'' is a small genus of shrubs with

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

, leathery, unlobed

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

arranged in alternate

phyllotaxy In botany, phyllotaxis () or phyllotaxy is the arrangement of leaves on a plant stem. Phyllotactic spirals form a distinctive class of patterns in nature. Leaf arrangement The basic arrangements of leaves on a stem are opposite and alterna ...

. The

inflorescences In botany, an inflorescence is a group or cluster of flowers arranged on a plant's 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 main axis ( pe ...

are axile and sessile; flowers emerge in bundles directly from the stem. The

flowers Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

are small and

tetramerous Merosity (from the greek "méros," which means "having parts")) refers to the number of component parts in a distinct whorl of a plant structure. The term is most commonly used in the context of a flower where it refers to the number of sepals in a ...

or pentamerous. They are directly attached to the stem via a

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 ...

with 2 basal

bracts In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also loo ...

. The calyx is mostly fused and forms 4 or 5 apical teeth, which are the unfused tips of the sepals. The 4 or 5

petals Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''coroll ...

are also fused into a short tube, and the inner surface of the corolla contains minute laciniate projections toward the base. The alternating

stamens 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 filamen ...

are lightly appressed to the corolla and have a short linear filament. The anthers are elongated, tubular, and erect. They face inward and release

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

through an apical pore. The

ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

is inferior and is divided into 4 or 5 locules with many ovules; the original description notes that the number of locules may vary by species. The

style Style, or styles may refer to: Film and television * ''Style'' (2001 film), a Hindi film starring Sharman Joshi, Riya Sen, Sahil Khan and Shilpi Mudgal * ''Style'' (2002 film), a Tamil drama film * ''Style'' (2004 film), a Burmese film * '' ...

is straight, with a stigma that is minutely thickened. The

nectary 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, ...

disc is ring-shaped and inconspicuous. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is subspherical and is crowned by the calyx. Members of ''Costera'' may be confused with ''

Vaccinium ''Vaccinium'' is a common and widespread genus of shrubs or dwarf shrubs in the heath family (Ericaceae). The fruits of many species are eaten by humans and some are of commercial importance, including the cranberry, blueberry, bilberry (wh ...

'', from which they can be distinguished by their glabrous leaves and lack of a line of articulation in the pedicel that is found in Bornean ''Vaccinium'' species. Their bundled, sessile inflorescences resemble those of '' Diplycosia''.

Taxonomy and naming

''Costera'' was described in the fourth volume of the ''Icones Bogoriensis'' in 1914 by

Johannes Jacobus Smith Johannes Jacobus Smith (Antwerp 29 June 1867 – Oegstgeest 14 January 1947) (sometimes written as Joannes Jacobus Smith) was a Dutch botanist who, between years 1905 to 1924, crossed the islands of the Dutch East Indies (mainly Java), collecting ...

. It is placed in the Vaccinieae, where it may be one of the most genetically divergent members. Smith named the genus after his mentor, Jan Constantijn Costerus. Smith records ''tjapien djanten'' as an indigenous name for the plant originating from the

Karimata Islands The Karimata Islands are a chain of small islands off the west coast of Indonesian Borneo, the largest of which is (Pulau) Karimata, being about across (east-west). It is part of Kayong Utara Regency of West Kalimantan province in Indonesia. Kar ...

. As of February 2023, it consists of 10 accepted species: * '' Costera borneensis'' J.J.Sm. * '' Costera cyclophylla'' (Airy Shaw) J.J.Sm. & Airy Shaw * '' Costera endertii'' J.J.Sm. * '' Costera lanaensis'' (Merr.) Airy Shaw & J.J.Sm. * '' Costera loheri'' (Merr.) Airy Shaw & J.J.Sm. * '' Costera lucida'' (Merr.) Airy Shaw & J.J.Sm. * '' Costera macrantha'' Argent * '' Costera ovalifolia'' J.J.Sm. * '' Costera sumatrana'' J.J.Sm. * '' Costera tetramera'' Sleumer

References

External links

* {{Taxonbar, from=Q8351366 Vaccinioideae Ericaceae genera