Begonia daunhitam
Species Information
Publication Date
2020
Origin
Endemic to Borneo (West Kalimantan, Indonesia). Specifically recorded from Sri Wangi Village, Boyan Tanjung District, Kapuas Hulu Regency.
Growth Type
Perennial, erect, terrestrial herb. It grows low to the ground, with a plant height of 15–25 cm.
Section
Chromosome = 2n =
Description
Begonia daunhitam is noted for its strongly bullate, dark foliage. Stems: Erect to 20 cm, 4–8 mm in diameter. Old stems are yellowish and slightly woody; young parts are red to brownish, fleshy, and succulent. Leaves: Alternate, simple, up to 10 on branched stems. The blade is elliptic-ovate to oblong-ovate, 13–20 cm long and 7–10 cm wide. The base is cordate and unequal (strongly asymmetric). Leaf Color & Texture: The adaxial (upper) surface is dark olive to solid black (dark bluish-green when immature) and is strongly bullate, giving it a bubbly appearance. The abaxial (lower) surface is light red to crimson. Leaf Margin: Denticulate (toothed). Unlike similar species, it lacks a silvery band along the margin. Flowers: The inflorescence is a bisexual, terminal or axillary dichasial cyme up to 25 cm long.
- Staminate (Male) Flowers: Pink-red with 2 tepals and 20–30 yellow stamens.
- Pistillate (Female) Flowers: Pink-red with 5 tepals and 3 golden yellow styles.
Fruit: A nodding capsule, light red to crimson, with 3 subequal wings.
Distribution
Endemic to West Kalimantan, Indonesia. So far only recorded from the type locality in Sri Wangi village.
Habitat
Grows in wet areas on slopes near rivers, under dense canopies of dipterocarp forest at elevations of 200–300 m asl.
Flower
Pink to red.
Etymology
The specific epithet is derived from the Indonesian language (Bahasa Indonesia): daun meaning "leaf" and hitam meaning "black," referring to the distinct dark olive to black color of the leaves.
Synonyms
No synonyms; this is a recently described species (2020).
Comparison to Similar Species
Begonia daunhitam is morphologically similar to Begonia darthvaderiana (found in Sarawak, Malaysia). Both belong to Sect. Petermannia and feature dark blackish leaves. They are distinguished as follows:
Photos
(Refer to Figures 1, 2 & 4 in the referenced PDF for habit, flower details, and distribution maps.)
Hybrids
Conservation status
Vulnerable (VUD2) (IUCN Red List criteria assessment proposed by authors). Only four subpopulations are found in a very restricted area. The species is threatened by potential over-collection for the ornamental plant trade and local agricultural activities.
External Links
References
Wang, W.G., Randi, A., Wang, C.X.L., Shen, J.Y., Ma, X.D., Shi, J.P., Xu, T. & Zhang, S.Z. (2020). Begonia daunhitam, a new species of Begonia (Begoniaceae) from West Kalimantan, Indonesia. Taiwania 65(1): 27–32.
