Monday, March 4, 2024

[Botany • 2024] Begonia matahom (Begoniaceae, sect. Petermannia) • A New Species from Tago, Surigao del Sur, Philippines


Begonia matahom F.A.Blasco, Alejandro, Tandang & Rubite, 

in Blasco, Alejandro, Tandang et Rubite, 2024. 

Abstract
In a recent field survey at Mt. Tingtingan, Badong, Tago, Surigao del Sur, an interesting Begonia with a robust habit was found. With the cane-like, erect and ascending or spreading suffrutescent stem, 2-tepaled staminate flowers and 5-tepaled pistillate flowers, this species belongs to section Petermannia. It's worth noting that the staminate and pistillate flowers of this species exhibit different tepal colors. This new Begonia resembles its Surigao ally B. benitotanii in having erect and glabrous stems, leaf adaxial surface with sparsely white spots between veins, obliquely cordate base, acuminate apex and serrated margin, but the new species named Begonia matahom is distinct in having larger stems that are woody and thick, ovate to triangular leaf shape, larger lamina, longer petioles, longer bracts, glabrous staminate tepals, yellowish-green pistillate flowers, stigmas in a curled spirally extended band with prominent cilia to conspicuously feathery, and smaller green ovary with glabrous and thick, unequal wings.

Keyword: Argostemma, Begonia benitotanii, limestone forest, Mindanao, Mt. Tingtingan, taxonomy

Begonia matahom F.A.Blasco, Alejandro, Tandang & Rubite. (Vegetative Parts)
A. and B. Habit and Habitat: Matured (L), Young (R), C. Stem, D. Stipules: Young (L), Matured (R), E. Leaves (Young and Mature).
All from Freddie A. Blasco 22-003.

Begonia matahom F.A.Blasco, Alejandro, Tandang & Rubite. (Reproductive Parts).
A. Staminate flower, B. Pistillate flowers C. Young pistillate flowers, D. Drying capsules in pairs, E. Staminate inflorescence with bracts, F. Cross section of the ovary, G. Matured capsules.
 All from Freddie. A. Blasco 22-003.


Begonia matahom F.A.Blasco, Alejandro, Tandang & Rubite, sp. nov. 
 Section Petermannia

Diagnosis: Begonia matahom resembles its Surigao ally B. benitotanii Rubite, Tandang & C.W. Lin in having erect and glabrous stems, leaf adaxial surface having sparse white spots between veins, obliquely cordate base, acuminate apex, with 2-tepaled staminate flowers and 5- tepaled pistillate flowers, but differs in having woody and thick stems (vs. semi-succulent), larger leaves 26–27 × 11–12 cm (vs. 8–21 × 6–12 cm), smooth staminate tepals (vs. wrinkled), curved and thick pistillate tepals (vs. flat and succulent), unequal capsule wings (vs. equal). Table 1 offers a thorough comparison of B. matahom and B. benitotanii.

Etymology: The specific epithet matahom is an archaic Bisayan word in the southern Philippines, which means beautiful, lovely, unique, and rare, referring to the distinct colors of the inflorescence.
 

Freddie A. Blasco, Grecebio Jonathan D. Alejandro, Danilo N. Tandang and Rosario R. Rubite. 2024. Begonia matahom (Section Petermannia, Begoniaceae), A New Species from Tago, Surigao del Sur, Philippines.  Taiwania. 69(1); 62-66. taiwania.ntu.edu.tw/abstract/1977