Begonia dinhtuana and Begonia caelata

Two new species, ๐ต๐‘’๐‘”๐‘œ๐‘›๐‘–๐‘Ž ๐‘‘๐‘–๐‘›โ„Ž๐‘ก๐‘ข๐‘Ž๐‘›๐‘Ž and ๐ต. ๐‘๐‘Ž๐‘’๐‘™๐‘Ž๐‘ก๐‘Ž (sect. ๐‘ƒ๐‘™๐‘Ž๐‘ก๐‘ฆ๐‘๐‘’๐‘›๐‘ก๐‘Ÿ๐‘ข๐‘š, Begoniaceae) from North Vietnam]

https://doi.org/10.6165/tai.2026.71.55

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Begonia ilinensis

Begonia ilinensisย is a newly described species ofย Begoniaย sect.ย Baryandra, first found in the coastal areas of Ilin Island, off the southwestern coasts of Mindoro Island in the Philippines. The species resides in exposed to semi-exposed limestone areas on the coast. The species is notable for its dormancy during the dry months, where it is limited to its minute rhizomes. It only starts growing its foliage and flowers during the wet season of June to November. Morphologically, the species is relatively small compared to mostย Baryandraย species in the Philippines, but resemblesย Begonia luzonensis, a resident of nearby Luzon Island, mainly by its leaf margins. However, the species is much smaller compared toย B. luzonensisย specifically in terms of lamina, inflorescences, and capsules, and it lacks the characteristic rusty villous indumentum ofย B. luzonensisย on its leaves, peduncles, and petioles. We also documented and mapped otherย Begoniaย sect.ย Baryandraย that we have found thriving on the same habitat asย B. ilinensisย on other portions of the Philippines to shed further insights on the ecology of these coastal Begonias based on their habitat preferences.