Hiding in plain sight: Two new species of Begonia section Petermannia (Begoniaceae) from the Philippines

A new species,Begonia subaequifolia Y.P.Ang & J.Collantes, is here described and illustrated from Luzon Island, Philippines. It closely resembles Begonia jagori Warb. by having an upright habit, stems covered with short brown hairs, short petioles, and an ellipticlamina with an oblique and shallowly cordate base. However,Begonia subaequifolia is distinct by having smaller stipules, sub-symmetrically oblong-ovate to narrowly elliptic-ovate lamina with pinnate venation, a crenate or serrulate leaf margin, the staminate inflorescence in a dichasial cyme, and smaller tepals in staminate flowers. We also report the rediscovery of B.loheri Merr., a poorly known Philippine endemic Begonia species, and provide an amended description, lectotypification, and photographs.

A new species of Begonia from Zamboanga del Norte, Mindanao Island, Philippines, is described. Begonia gigang is morphologically similar to Begonia corazoniae but can be distinguished by having smaller leaves which are hirsute on both surfaces, longer panicles and peduncles, shorter pedicels for both staminate and pistillate flowers, and trigonous-ellipsoid ovary. Begonia gigang is assessed as Endangered under the IUCN Red List Categories and Criteria. A detailed description, photographs, and ecological notes, and are provided.

A new Begonia section Petermannia species, Begonia corazoniae Naive, discovered in the forest ecosystems of Davao Oriental, southeastern Mindanao, Philippines, is herein described and illustrated. It closely resembles B. rieckei, but is easily recognized by having paniculate inflorescences with prominently winged ovary and capsule. A comprehensive morphological description, geographic distribution, ecology, phenology and a discussion of similar species is provided. In addition, we assessed this species as ‘Endangered' (EN B1(iii) + 2(iii)) following the criteria of the IUCN.

A new Begonia species, Begonia abhak, from section Petermannia is described and illustrated. Growing on shady, moist, rocky slopes alongside a small creek of Bujon, Lanuza, Surigao del Sur. The new species resembles Begonia panayensis in having glabrous stems, membranous, shiny leaves, oblong to oblanceolate lamina, acuminate apex and green ovary with pink wings but is distinct in having short stems, broadly ovate stipules, acute leaf base, serrated margins, and the slashed or jagged to almost entire margins of the capsule wings. Based on IUCN criteria, B. abhak is hereby proposed as Least Concern (LC).

In documenting the flora of Mt. Malinao, Albay Province, Bicol region, Philippines an unknown Begonia from section Petermannia was discovered in the higher altitudes. Further study of relevant specimens and protologue identified it as Begonia jagori, a species endemic to the Philippines. Begonia jagori was known from a single collection in 1861 and since then, it has not been recollected or redocumented again. The collection locality was listed broadly as Luzon, and the protologue lacked some details. Using the materials from Mt. Malinao, the plant was redescribed and lectotypified. A note comparing its affinity to B. cumingiana is provided.

A subspecies new to science, Begonia bangsamoro subsp. bagasa Naive (section Petermannia) discovered in Zamboanga del Sur, Western Mindanao, Philippines is herewith described and illustrated. The new subspecies differs significantly from the type subspecies in having staminate and pistillate flowers with very narrow tepals. A colour plate, notes on its distribution, habitat, phenology, proposed conservation assessment based on IUCN criteria as well as a checklist of Begonia species present in Zamboanga Peninsula are provided. With this discovery, Zamboanga Peninsula now holds a total of 17 Begonia taxa, and the very first subspecies described for the Philippine archipelago.

Two new species of Begonia section Petermannia from Zamboanga del Norte, Philippines are described and illustrated: Begonia amamampang and Begonia turugsoy. Begonia parvilimba was also rediscovered and an updated description is provided. All morphological characters and measurements were observed in the wild from living plants. This brings the record to a total of 16 Begonia species under this section found in the region of Zamboanga Peninsula making Zamboanga a center of diversity of section Petermannia in the Philippines. Notes on their ecology, distribution map and proposed conservation assessment are provided.

Taxonomy of the genus Begonia (Begoniaceae) in Mindanao, Philippines II: lectotypification of two Begonia section Petermannia species from the Zamboanga Peninsula

Taxonomy of the genus Begonia (Begoniaceae) in Mindanao, Philippines I: Begonia olganunezae, a new Begonia section Petermannia species discovered in the province of Bukidnon

In 2011 and later in a 2018 field survey, an unknown Begonia species allied to taxa in section Petermannia was found in Bucas Grande Island. After thorough studies of the living plant, literature, and herbarium specimens we name the new species Begonia benitotanii, to honor Dr. Benito C. Tan, the internationally known Filipino muscologist. In 2011, there were two populations observed, each of about 300 individuals in a 100 m area. During recent fieldwork, one population was found decimated while the other was reduced to just about 50 individuals. The site is being converted into coconut, banana, and rice plantations. The area is not currently protected under the country’s National Integrated Protected Areas System by the Department of Environment and Natural Resources. According to the IUCN red list categories and criteria, B. benitotanii is hereby proposed to be placed under the Critically Endangered (CR) category.

Begonia bangsamoro, a new Philippine Begonia species from the section Petermannia is described and illustrated. The new species was discovered in the fragmented riparian forest of Lanao del Sur, along the Ginapukan river in Wao, Mindanao island, Philippines. The previous collections also revealed that it occurs in the nearby province of Bukidnon. Begonia bangsamoro is distinguished from other Philippine Begonia by its lacerate leaf margins, terminal inflorescences, 4-tepaled staminate flowers, and sparsely hirsute ovaries. The new species is compared with the phenetically similar B. quercifolia. Based on IUCN Red List criteria, B. bangsamoro is designated as Endangered (EN).

ARDI, W. H. & THOMAS, D. C. 2020. Begonia tjiasmantoi, a new species from West Sulawesi. Reinwardtia 19(1): 61‒65. ‒‒ A new species, Begonia tjiasmantoi Ardi & D.C.Thomas is described from Mamasa, West Sulawesi, Indonesia. The species is endemic to West Sulawesi and belongs to Begonia section Petermannia. A provisional conservation assessment indicates a Critically Endangered status.

A new species of Begonia, Begonia medicinalis Ardi & D.C.Thomas, is described from Sulawesi, Indonesia. A photo plate and distribution map are provided. The new species is endemic to Sulawesi and belongs to Begonia section Petermannia.

Anatomical study on native Begonia in Cibodas Botanical Garden was conducted to determine their stomata types. Stomata 32 native Begonia were prepared by semi-permanent methods. Parameters observed in this study were stomata type, number, and size of stomata. The result showed that all Begonia species have anisocytic stomata and those stomata only found in abaxial leaves. Based on number of stomata, these Begonia can be classified into two groups: single stomata and single-grouped stomata. Generally, Begonia has a single stomata, however, single-grouped stomata is a determinate character of Begonia sect. Reichenheimia and sect. Diploclinium in CBG. The differences of stomata distribution in B. ozotothrix with other members of section Petermannia are needed to be clarified further.

The pantropically distributed Begonia (Begoniaceae) is one of the most species-rich genera. Philippines is one of the diversity centers of Southeast Asian Begonia. In our 2012 field survey, three species of Begonia section Petermannia were collected in Barangay Sagubo, Municipality of Kapangan, Province of Benguet in the northern Luzon Island, Philippines. Our study on literatures and herbarium specimens suggests that these collections consist of B. crispipila, an unknown new species hereby we named B. balangcodiae, and the natural hybrid between them. Molecular analyses confirm that the former contributed the maternal genome while the latter provided the paternal genome. We name the natural hybrid B. × kapangan, which is the first natural hybrid reported in sect. Petermannia.

Two new species of Begonia, B. inggitiae and B. dracopelta, are described from Borneo. Begonia inggitiae is endemic to Kalimantan, and B. dracopelta is found in both Kalimantan and Sarawak, and both belong to Begonia section Petermannia.

Recent exploration in Mt. Ararat, Bayugan City, Agusan del Sur resulted in a collection initially identified as Begonia bolsteri, a poorly known Philippine endemic species first described over a century ago. Examination of the types of this species and the type of B. colorata led us to the conclusion that these names represent the same taxon, and we place them in synonymy under the earlier name of B. colorata and designate lectotypes for both names. In this paper, we provide a comprehensive description for the species and photographs to facilitate easy identification.

Material acquired on a recent expedition to Southeastern Sulawesi, Indonesia, presents an opportunity to reassess and provide an overview of the Begonia flora of the region. Eleven species are recognized including four new species described and illustrated here: Begonia incudiformicarpa, B. iskandariana, and B. tumburanoensis (all in Begonia section Jackia); and B. johntania (Begonia section Petermannia). The former three species are the first confirmed records of section Jackia on Sulawesi substantially extending the known eastern range limit of this section. In addition, an illustration and a lectotypification of Begonia flacca are presented, and an identification key to Begonia species in Southeastern Sulawesi is provided.

Two new species of Begonia (Begoniaceae) from the section Petermannia are described from the Berau Regency, East Borneo: B. ltahensis Girm. and B. duhungensis Girm. The habit of B. ltahensis is similar to B. calcarea, currently known only from the Ltah river in lowland mixed Dipterocarp forest in Long Duhung, Kelay District, Berau Regency. Meanwhile, B. duhungensis is similar to B. heliostrophe from Sabah, found near Long Duhung village. A distribution map, images and conservation status are provided for each taxon.