''Goniothalamus velutinus'' is a species of

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

in the family Annonaceae. It is native to

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

. Herbert Airy Shaw, the English botanist who first formally described the species, named it after the dense velvety ( in Latin) hair on its branchlets and petioles.

Description

It is a tree reaching 6 meters in height. Its smooth, dark grey to black, young branches are covered in dense, rust-colored, velvety hairs. Its cylindrical petioles are 1.3-2.2 by 0.5-0.8 centimeters and covered in dense, rust-colored, velvety hairs. Its papery to leathery, oblong to lance-shaped leaves are 24-60 by 6.5-12.5 centimeters with rounded apices that end in an abrupt, tapering tip and pointed bases. The leaves have margins that are curved toward underside with upper surfaces that are brown to green and covered in fine hairs, and lower surfaces that are green to brown and covered in dense, matted, woolly hairs. The leaf midribs are sunken, grooved and covered with hair on the upper surface; raised and covered in dense, matted, velvety to wooly hairs beneath. The leaves have 22-25 pairs of secondary veins emanating from their midribs. Its green flowers have 6 petals arranged in two rows of three. The flowers are born on

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence. Such inflorescences are described as ''pedicellate''. Description Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...

that are 5-9 millimeters long. The pedicels have up to 4

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

s that are 2-4 millimeters long at their base. Its triangular to oval

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s are 7 by 4 millimeters with pointed tips. The sepals are fused over a short portion of their base. The oval to lance-shaped outer petals are 10–14 by 4–6 millimeters with pointed to tapering tips and rounded bases. A portion of the inner surface of the outer petals is covered in dense, matted, woolly hairs. The oval inner petals are 5–10 by 2–4 millimeters. The basal 4 millimeters of the inner petals are wedge-shaped, and their tips are tightly fused. The margins of the inner petals are curved back and covered in dense, woolly hairs. Its flowers have approximately 140 oblong to wedge-shaped

stamen 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 filame ...

that are 2 millimeters long. The connective tissue between the lobes of the anther forms a hemispherical cap that is covered in dense, minute hairs. Its flowers have 12-16 oval to spindle-shaped

carpels Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

that are 2 millimeters long with negligible styles. The bases of the carpels are covered in long rust-colored hairs. Its stigmas are small and minutely bilobed.

Reproductive biology

The pollen of ''G. velutinus'' is shed as permanent tetrads.

Habitat and distribution

It has been observed growing in peat swamps and by streams in primary forests at elevations below 300 meters.

Uses

Bioactive compounds extracted from its bark have been reported to have

antioxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...

activities using ''in vitro'' tests, anti-

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

activity in tests with ''

Streptococcus mutans ''Streptococcus mutans'' is a facultatively anaerobic, gram-positive coccus (round bacterium) commonly found in the human oral cavity and is a significant contributor to tooth decay. It is part of the " streptococci" (plural, non-italic lowercase ...

'' and ''

Proteus mirabilis ''Proteus mirabilis'' is a Gram-negative, facultatively anaerobic, rod-shaped bacterium. It shows swarming motility and urease activity. ''P. mirabilis'' causes 90% of all ''Proteus'' infections in humans. It is widely distributed in soil and ...

'', and

cytostatic Cytostasis (cyto – cell; stasis – stoppage) is the inhibition of cell growth and multiplication. Cytostatic refers to a cellular component or medicine that inhibits cell division. Cytostasis is an important prerequisite for structured multic ...

activity in tests with cultured human cancer cells.

References

{{Taxonbar, from=Q15359588 velutinus Flora of Borneo Plants described in 1939 Taxa named by Herbert Kenneth Airy Shaw