Saurauia bracteosa is a species of flowering plant in the family Actinidiaceae, which also includes kiwifruit. It is a shrub or small tree native to tropical and subtropical regions of Southeast Asia. The specific epithet "bracteosa" refers to its prominent and persistent bracts, which are characteristic features of the species.
Description
Saurauia bracteosa typically grows as a shrub or small tree, reaching heights of 3 to 8 meters. Its branchlets are densely covered with brown, pilose (softly hairy) indumentum.
- Leaves: The leaves are alternate, with petioles 1.5-3 cm long. The leaf blade is elliptic, oblong-elliptic, or oblanceolate, measuring 10-25 cm in length and 3-9 cm in width. They are papery in texture, with the abaxial (underside) surface densely brown pilose and the adaxial (upper) surface sparsely hirtellous. The leaf base is cuneate, the margin is serrulate, and the apex is acuminate. Prominent secondary veins (12-18 pairs) and reticulate venation are visible on both surfaces.
- Flowers: The inflorescences are axillary cymes, typically bearing 3-7 flowers. The peduncle is 1-2.5 cm long and pilose. A distinguishing feature are the bracts, which are broadly ovate to orbicular, about 1.5 cm in diameter, persistent, and densely brown pilose. The flowers are 1.5-2 cm in diameter, borne on pedicels 1.5-2 cm long.
- Sepals: There are 5 sepals, which are broadly ovate or orbicular and unequal in size, with the outer two larger (ca. 1.2 cm) than the inner three (ca. 0.8 cm). They are densely brown pilose on the abaxial surface and glabrous on the adaxial surface.
- Petals: The 5 petals are pink or white and obovate-oblong.
- Stamens: Numerous stamens are present.
- Ovary: The ovary is densely brown pilose, with 5 styles connate (fused) at the base.
- Fruit: Information regarding the fruit is not consistently described in major botanical floras, suggesting it may be unrecorded or rarely observed.
Distribution and Habitat
Saurauia bracteosa is native to parts of mainland Southeast Asia. Its distribution includes southern Yunnan province in China (specifically Xishuangbanna) and extending into Laos, Myanmar, Thailand, and Vietnam.
It typically thrives in moist, tropical environments. Its preferred habitats include forest margins, roadsides, and thickets, at elevations ranging from 500 to 1500 meters above sea level.
Taxonomy
Saurauia bracteosa belongs to the genus Saurauia, which is the largest genus within the family Actinidiaceae. The genus comprises approximately 300 species distributed across tropical and subtropical Asia, Central America, and South America. Saurauia bracteosa was first described by Adolph Daniel Edward Elmer.
- Family: Actinidiaceae
- Genus: Saurauia
- Species: Saurauia bracteosa
Etymology
The genus name Saurauia honors Francis de Paula Adam von Saurau (1760-1832), an Austrian statesman and botanist. The specific epithet bracteosa is derived from Latin, meaning "full of bracts" or "having conspicuous bracts," referring to the prominent and persistent leaf-like structures associated with its flowers.
Conservation Status
The conservation status of Saurauia bracteosa has not been specifically assessed by the IUCN Red List. Like many species in its tropical forest habitats, it may face threats from habitat loss due to deforestation and land conversion, though a comprehensive evaluation is lacking.