A new species of Begonia section Baryandra from Zamboanga Peninsula, Southwestern Philippines

. A new species of Begonia sect. Baryandra , B. sebodensis, from Zamboanga del Norte, southwestern Philippines is described and illustrated. Begonia sebodensis is morphologically similar to B. anisoptera in obliquely ovate to widely ovate leaves, four-tepaled staminate and pistillate flowers and three locular ovary but differs in gla-brescent stipules, sericeous petioles, leaf margins distantly serrate and ciliate, many-flowered inflorescences, capsule wings subequal and flat. Following IUCN criteria, we propose B. sebodensis as Endangered (EN).

The region of Zamboanga Peninsula, southwestern Mindanao is one of the botanically unexplored areas in the Philippines.Based on herbarium records and literature, 17 species and one subspecies of Begonia were recorded in Zamboanga Peninsula (Naive et al. 2022;Mazo et al. 2022).Begonia sect.Baryandra is represented by a single species in the region, Begonia anisoptera Merr., and all the remaining taxa belong to Begonia sect.Petermannia.
During a botanical exploration in the municipality of President Manuel A. Roxas (PMAR), Zamboanga del Norte (Fig. 1), a rhizomatous Begonia with 4-tepaled staminate and pistillate flowers, and 3-locular ovary was documented.These characters indicate that it is a member of the B. sect.Baryan-dra.Based on a detailed examination of morphological characters of the collected material and closely related species, we concluded that it is new to science, which is hereby named Begonia sebodensis Mazo & Rubite (Fig. 2) and described as the second representative of the B. sect.Baryandra in Zamboanga Peninsula, Philippines.

Etymology
The specific epithet derived from the locality where the new species was collected.

Phenology
Observed flowering and fruiting from March to June.

Distribution and ecology
Begonia sebodensis is endemic to Zamboanga Peninsula and is currently known only from the municipalities of President Manuel A. Roxas, and Katipunan, Zamboanga del Norte (Fig. 1).It grows on rocks and vertical cliffs in shady areas at elevations of 200-500 meters above sea level.In the type locality, the plant associated with B. sebodensis includes Homalomena philippinensis Engl.(Araceae), Monophyllaea merrilliana Kraenzl.(Gesneriaceae), and species of Ficus L. (Moraceae), Elatostema J.R.Forst.& G.Forst.(Urticaceae), and Calamus L. (Arecaceae).

Proposed conservation assessment
Begonia sebodensis is only known from two barangays of two different municipalities in Zamboanga del Norte: Barangay Sebod, President Manuel A. Roxas, and Barangay Miatan, Katipunan.In the two barangays, total of 10 to 15 subpopulations were recorded with less than 100 mature individuals.The type locality is near a waterfalls which is being developed as a tourist destination, vegetation in the area is being cleared and planted with ornamental plants, the falls is frequently visited by local tourists.The two barangays are near farm lots and charcoal making was also observed.These barangays where the B. sebodensis were recorded are currently not protected under the country's National Integrated Protected Areas System by the Department of Environment and Natural Resources.Following IUCN red list and criteria (IUCN 2022), Begonia sebodensis is hereby proposed as Endangered [EN, D].

Figure 1 .
Figure 1.Map showing the distribution (left) and habitat (right) of Begonia sebodensis in Zamboanga Peninsula.