Taxonomic notes
Thottea philippinensis was originally described by Eduardo Quisumbing in 1930 based on specimens collected by T.N. Roque from Lanao Province in the island of Mindanao. Although it has been recollected twice in Sarawak (Hou 1984), the species have never been rediscovered in the Philippines since it was first discovered. Through our extensive fieldwork in Zamboanga Peninsula, on the island of Mindanao, the species has recently been rediscovered after a lapse of 93 years.
According to Hou (1984), Thottea philippinensis closely resemblesT. celebica of Sulawesi (previously known as Celebes). However,T. philippinensis differs significantly in having these following characters: puberolous stem (vs. pubescent in T. celebica ); leaves lateral veins up to 13 (vs. leaves lateral veins up to 10 inT. celebica ); broadly triangular with acute apex perianth lobes (vs. semi-orbicular with subrotund or slightly apiculate apex perianth lobes in T. celebica ); and 4–6 style lobes (vs. c. 12 style lobes in T. celebica ).
Thottea tomentosa (Blume) Ding Hou, Blumea 27(2): 328, f. 48, 49 (1981); Hou, Fl. Males., ser. 1, 10: 79 (1984); Yao, Fl. Pen. Malaysia 5: 43 (2015). – Ceramium tomentosum Blume, Bijdr. Fl. Ned. Ind. 17: 1135 (1827). – Bragantia tomentosa (Blume) Blume, Enum. Pl. Javae 1: 82 (1827); Ridley, J. Straits Branch Roy. Asiat. Soc. 57: 89 (1910); Ridley, J. Straits Branch Roy. Asiat. Soc. 59: 161 (1911). – Apama tomentosa (Blume) Engl. ex Soler., Naturl. Pflanzenfam. 3(1): 272 (1889); Backer & Bakhuizen f., Fl. Java 1: 162 (1964). (Fig. 3)
Type: INDONESIA. Java, Herb. Blume ‘1690’ (lectotype L [L0038821], designated by Hou (1981); isolectotype L [L0038822]).
Thottea tomentosa is one of the widest-ranging species of the genus distributed from India (Assam: Manipur & S. Andaman Is.), Bangladesh (Sylhet), Burma (Moulmein), South Vietnam (Bien Hoá), Peninsular Thailand. In Malesia, it is found in the Malay Peninsula (throughout), Sumatra, West & Central Java, and the Philippines (Jayabas, Alabat I., Panay, Mindanao), but it has not yet been found in Borneo. Although it was reported to occur in the Philippines, this has become doubtful due to the T. tomentosa found having eight stamens instead of six, as consistently mentioned in previous studies (Hou 1981, 1984, Yao 2015, Mustaqim et al. 2022). Therefore, it is treated as incertae sedis in Co’s Digital Flora of the Philippines (Pelser et al. 2011 onwards). During our recent extensive fieldwork conducted in Pasonanca Natural Park, Zamboanga City, we successfully collected a Thottea species that possesses six stamens, perfectly matching the characteristics of T. tomentosa . Consequently, in this paper, we definitively affirm its presence in the Philippine archipelago, currently restricted to Zamboanga City. However, other specimens identified as T. tomentosa present in other parts of the archipelago warrant further investigation, as they may potentially represent a new species.