Phytotaxa 288 (3): 296–300 http://www.mapress.com/j/pt/ Copyright © 2016 Magnolia Press Article PHYTOTAXA ISSN 1179-3155 (print edition) ISSN 1179-3163 (online edition) 296 Accepted by Axel Arriola: 2 Dec. 2016; published: 16 Dec. 2016 http://dx.doi.org/10.11646/phytotaxa.288.3.12 A new Philippine endemic species and new records of Lasianthus (Lasiantheae, Rubiaceae) MUHAMMAD JEFTE C. ARSHED 1 & GRECEBIO JONATHAN D. ALEJANDRO 1,2,3 1 The Graduate School, 2 College of Science and 3 Research Center for the Natural & Applied Sciences, University of Santo Tomas, Es- paña, Manila, 1015, Philippines Email:jeftearshed@yahoo.com, grecebio.jonathan.alejandro@ust.edu.ph/ balejan@yahoo.com Abstract A new species named as Lasianthus halconensis from Mt. Halcon, Mindoro, Philippines is described and illustrated. This species is easily distinguished from the other Lasianthus by having strigose indumentum on branches, abaxial leaf surface, petioles and calyx; lanceolate leaves, cuneate at base; obconical calyx and drupes with 8 pyrenes. This species is allied to L. obliquinervis and L. chrysoneurus but differs in stem, leaf and calyx indumentum, leaf and calyx shape and the absence of bracts. Moreover, three new records of Lasianthus in the country are reported including their diagnosis. Introduction Lasianthus Jack (1823:125) is the largest genus within the tribe Lasiantheae. The genus consists of 225 species and with the highest diversity in tropical and subtropical Asia (Smedmark et al., 2014). The Lasianthus species are usually shrubs or treelets; often with existing hairs on the branchlets, petioles, lower leaf surface on midrib and veins and stipules; variable leaves either in shape and size; inflorescences with axillary, sessile, fascicled, or pedunculate cymes and drupes with crown and persistent calyx lobe (Zhu, 2001). Circumscription of Lasianthus is mainly based on vegetative characters and limited reproductive characters such as the number of pyrenes or locules thus making the species level classification difficult (Zhu, 2001; Zhu et al., 2012). For Asian representatives, Lasianthus is defined as drupes comprising 2–9 mature pyrenes with a thick wall that develop from the ovaries with 2–9 locules (Zhu et al., 2012). The Philippine Lasianthus was first enumerated by Merrill (1923) which comprises 15 species, 11 of which are endemic. In the recent Malesian revision of Lasianthus, Zhu et al. (2012) recognized a total of 22 Philippine Lasianthus species in which five are endemic and one was excluded from the genus. Recent floristic collections conducted in Mt. Halcon (Mindoro island), Mt. Timpoong (Camiguin island) and Sabang (Palawan island) revealed a divergent Lasianthus species and three new records for the Philippines. Upon careful examination and comparison to type specimens and existing literature, there was no matching description for the divergent Lasianthus. Thus, we proposed a new endemic Lasianthus from Mt. Halcon. We also recognized new records of the genus from Camiguin and Palawan islands. Materials and Methods The Lasianthus specimens were collected from Mt. Halcon, Mindoro; Mt. Timpoong, Camiquin and Sabang, Palawan. Measurements, color and other details given in the descriptions are based on field observations, herbarium specimens and reproductive parts preserved in 70% ethanol. Details of vegetative and reproductive parts were observed using Olympus SZ51 dissecting microscope. Examination of available Lasianthus specimens from local herbaria (PNH, PUH, PSUH, CAHUP and USTH) and digital images of types from international herbaria (K, L, NY, and US) were used to compare the specimens. Herbarium specimens were deposited at the Philippine National Herbarium (PNH) and the University of Santo Tomas Herbarium (USTH).