Syzygium filipes, Merr., Philipp. J. Sci.

Fernando, E. S., Quimado, M. O. & Mansibang, J. A., 2024, Two New Species Of Syzygium (Myrtaceae) From Ultramafic Soils In Northeastern Mindanao, Philippines, With Notes On Three Other Rare Species, Edinburgh Journal of Botany 81 (2027), pp. 1-19 : 12-15

SYZYgium filipeS Merr., Philipp. J. Sci. 79 (1950) 390. – Type: Philippines, Mindanao Island,

Surigao Province , vi 1919, M. Ramos & G. Edaño BS 34723 (holotype A [ A00071505 ], designated by Merrill (1950); isotypes K [ K000800266 ], US [ US 1263737]). Figure 5 .

Distribution. Endemic to the Philippines. Mindanao Island, Surigao del Norte Province.

Proposed IUCN conservation category. Using GeoCAT ( Bachman et al., 2011; http://www. geocat.kew.org), an EOO of less than 100 km 2, which is within the threshold for the

Critically Endangered category, was calculated, in addition to an AOO of 12 km 2, which is within the threshold for an Endangered category. The known localities of this species are all within a mining area. Following the IUCN Red List Categories ( IUCN, 2012) and the recommendation to use a precautionary approach in conservation assessments ( IUCN Standards and Petitions Subcommittee, 2022), we assess this species as Endangered [EN B1+B2b(i,ii,iii,iv,v)].

Notes. This species falls under the Myrtifolium group of Robinson (1909). Vegetatively, this group consist of species with a generally elliptic-oblong lamina, acute-obtuse leaf base, acute-acuminate apex, and thin secondary venation, but most importantly for inclusion in the Myrtifolium group, the possession of small turbinate flowers, inconspicuous and small calyx lobes (i.e. hypanthium rim subtruncate), pseudo-calyptrate corolla, small fruits, pericarp ripening to fleshy texture and purplish-black colour.

Information from the late Leonard L. Co ( Pelser et al., 2011 onwards) includes a note of the similarity of Syzygium filipes to S. rostratum (Blume) De Candolle from Sumatra, Java, and Borneo. However, Syzygium filipes is readily distinguished by its elongated, gracile inflorescence/infructescence axes.

Additional specimens examined. PHILIPPINES. Mindanao Island: Surigao del Norte, Claver , 170 m elevation, 6 xi 2022 (fr), E. S. Fernando 5223 ( LBC, PNH) ; ibid., 210 m elevation, 22 vi 2023 (fl buds), E. S. Fernando 5409 ( LBC, PNH, PUH, SING) .

Syzygium siderocolum (Merr.) Merr., Philipp. J. Sci. 79 (1950) 414, excl. syn. ‘ Eugenia similis ’ (which is the printer’s error for ‘ Eugenia sidericola ’). Eugenia siderocola Merr., Philipp. J. Sci. 18 (1921) 303. – Type: Philippines, Mindanao Island, Surigao Province, on ridges and along streams at the iron deposit on the northeast coast, extending from low elevations to at least 650 m, 4 vi 1919, M. Ramos & J. Pascasio BS 34521 (lectotype A [A00069783] designated here!; isolectotypes K [K000800306], P [P05229088], US [ US 00118159]); paratype: Philippines, Mindanao Island, Surigao Province, on ridges and along streams at the iron deposit on the northeast coast, extending from low altitudes to at least 650 m, 4 vi 1919, M. Ramos & J. Pascasio BS 34722 (not found). Figure 6.

Distribution. Endemic to the Philippines. Mindanao Island, Surigao del Norte Province.

Proposed IUCN conservation category. Using GeoCAT ( Bachman et al., 2011; https://www. geocat.kew.org), an EOO of less than 100 km 2, which is within the threshold for the Critically Endangered category, was calculated, in addition to an AOO of 12 km 2, which is within the threshold for the Endangered category. The known localities of this species are all within a mining area. Following the IUCN Red List Categories ( IUCN, 2012) and the recommendation to use a precautionary approach in conservation assessments ( IUCN Standards and Petitions Subcommittee, 2022), we assess this species as Endangered [EN B1+B2b(i,ii,iii,iv,v)].

Notes. This species grows on ridges and along streams at low elevations. According to L. L. Co ( Pelser et al., 2011 onwards), it is known only from the original two collections. In the protologue, Syzygium siderocolum was compared with S. cagayanense (Merr.) Merr. It can be distinguished from all other species of Philippine Syzygium by its strikingly small growth habit, flexuous twig, small and oblong lamina, obtuse-rounded apex, terminal inflorescence, and most importantly, an inconspicuous secondary venation.

Additional specimens examined. PHILIPPINES. Mindanao Island: Surigao del Norte, Claver , along a streambank, 35 m elevation, 5 ix 2022 (fr young), E. S. Fernando 5180 ( LBC, PNH) ; ibid., 114 m elevation, 20 vi 2023 (fl buds), E. S. Fernando 5396 ( K, LBC, PNH, PUH, SING) .

Syzygium surigaense (Merr.) Merr., Philipp. J. Sci. 79 (1950) 417. – Eugenia surigaensis Merr., Philipp. J. Sci. 18 (1921) 297. – Type: Philippines, Mindanao Island, Surigao Province, along streams at low altitudes at the iron deposit on the northeast coast, 14

vi 1919, M. Ramos & J. Pascasio BS 34686 (lectotype A [ A00069806 ], designated here!; isolectotypes K [ K000800349 ], P [ P05229209 ], US [ US 00118184]). Figure 7 .

Distribution. Endemic to the Philippines. Mindanao Island, Surigao del Norte Province.

Proposed IUCN conservation category. This species has a small population size, with only a single mature fruiting individual recorded. This plant was about 7 m tall with a 10 cm stem diameter ( Figure 7A) and was seen in April 2019 at low elevation along a stream, from which area herbarium specimens were collected. The species may occur in similar habitats elsewhere in the vicinity. However, given that the whole area is part of a surface mining project, the remaining individuals of this species, if any, face real threat to their survival from habitat loss. Considering its EOO, AOO and area, extent and/or quality of habitat; the number of mature individuals; and a projected continuing decline in habitat quality and quantity, Syzygium surigaense is assessed as Critically Endangered [CR) C+C2a(i)].

Notes. According to L. L. Co ( Pelser et al., 2011 onwards), this species is, thus far, known only from the type specimen. It was compared with Syzygium megalanthum (C.B.Rob.) Merr. because of its solitary- to few-flowered inflorescence, turbinate hypanthium, rim 2–3 cm in diameter, and large, persistent calyx lobes, but strongly differs from that species by its thick and corky petioles, fewer secondary veins, eglandular lamina, and broader leaf base.

Additional specimen examined. PHILIPPINES. Mindanao Island: Surigao del Norte, Claver , along a stream, 37 m elevation, 26 iv 2019 (fr), E. S. Fernando 4714 ( LBC, PNH, PUH) .