You ‘Sau’ Me! A new species and a rediscovery in the genus Saurauia (Actinidiaceae) from Zamboanga Peninsula, Mindanao Island, Philippines

A new species and a rediscovery in the genus Saurauia (Actinidiaceae) from Zamboanga Peninsula, Mindanao island, Philippines are presented here. The new species, Saurauia abbreviata, closely resembles Saurauia lanaensis Merr. but can be differentiated by having longer petioles, uniformly setose adaxial leaf surface, longer and wider leaves, more lateral veins, 3 styles, and a 3(–4)-locular ovary. This discovery raises the current number of recognized Saurauia in the Philippines to 57 following an 87-year gap in the taxonomic study of this genus in the country. S. longipedicellata Merr. is also rediscovered after almost a century. A lectotype is here assigned for this name selected among the syntypes. Photographs, ecological notes, and an amended description are also provided to aid taxonomic identification. Abstrak. Usa ka bag-ong species ug nadiskobrehan pag-usab sa genus nga Saurauia (Actinidiaceae) gikan sa Zamboanga Peninsula, isla sa Mindanao, Philippines ang gipresentar dinhi. Ang bag-ong species, Saurauia abbreviata, nahisama pag-ayo sa Saurauia lanaensis Merr. apan ang bag-ong species adunay labi ka taas nga mga petioles, uniformly setose ang ilalom nga dahon, mas taas ug mas lapad nga dahon, labi pang mga lateral veins, 3 styles, ug 3(–4)-locular nga obaryo. Ang nadiskobrehan nagdugang sa kadaghanon sa mga giila nga Saurauia sa Pilipinas ngadto sa 57 human sa 87 ka tuig nga gintang sa taxonomic nga pagtuon sa kini nga genus sa nasud. Ang Saurauia longipedicellata Merr. nadiskobrehan usab pagkahuman sa hapit usa ka gatus ka tuig. Ang tipipikasyon gihimo dinhi aron mapalig-og ang ngalan. Mga litrato, mga notang ekolohikal, ug giusab nga hulagway alang sa maong species makita usab dinhi.


INTRODUCTION
Saurauia Willd. is a large genus currently composed of ca. 300 species distributed in the tropical and sub-tropical areas of both the old and new worlds (Briggs 2015). Together with the genera Actinidia Lindl. and Clematoclethra (Franch.) Maxim., Saurauia is currently included in the family Actinidiaceae Engl. & Gilg (POWO 2019). Advancement in the taxonomy of Saurauia has been hampered due to the extent of morphological variation within species being largely undetermined. This has made species delineation difficult, and recognizing undescribed taxa very challenging (Conn & Damas 2013), especially in the Malesian Region where a great diversity of this taxon is largely unknown up to date.
The first species of Saurauia described for the Philippines, S. latibractea Choisy, was based on a collection by Hugh Cuming, who collected natural history collections there from 1836 to 1839 (van Welzen 2017). Elmer Drew Merrill continued the advancement in the study of this genus during the American occupation of the Philippines with 6 species published in the Govt. Lab. Publ. 35 (Merrill 1906). He likewise mentioned 48 species in his Enum. Philipp. Flow. Plants (EPFP) III (1923) and EPFP IV (1925). Moreover, S. gigantifolia Quisumb. and S. knemifolia Quisumb. were added to the list in 1944. Leonard Co updated the species checklist containing 56 taxon [excluding S. cordata Quisumb., the name however is accepted in the current checklist (Pelser et al. 2011 onwards)]. His unfinished manuscript laid the foundation of Co's Digital Flora of the Philippines (philippineplants.org) (Barcelona et al. 2013), an updated checklist of Philippine vascular plants (Pelser et al. 2011 onwards). This online database currently recognizes 56 species of Saurauia. There are currently 20 species recorded on the island of Mindanao.
The Zamboanga peninsula ( Fig. 1) in Mindanao island comprises 3 provinces: Zamboanga del Norte, Zamboanga del Sur, and Zamboanga Sibugay. This region is regarded as one of the cultural and ecological centers of the island. Historically, Zamboanga flora had been extensively studied through various expeditions in the 1900s. These expeditions generated specimens of a number of narrowly endemic species-many of which are yet to be rediscovered in the wild. Some noteworthy endemic plants are Aeschynanthus zamboangensis Kraenzl., Begonia zamboangensis Merr., Cymboglossum zamboangense (Ames) Ormerod & Cootes, and Pandanus zamboangensis Martelli.
During fieldwork in the Municipality of Leon B. Postigo in Zamboanga del Norte, the first author documented an interesting Saurauia species bearing small, few-flowered axillary cymes. The plant was initially identified as S. lanaensis Merr. because of its abaxially setose leaves and very short inflorescences. However, review of literature, comparison with protologues and herbarium specimens in JSTOR proved that the specimen represents an undescribed taxon. Thus, we here formally describe and name this new species as Saurauia abbreviata K.R.Mazo. This discovery is the latest addition to the genus after an 87-year gap in knowledge in studying this taxon of Actinidiaceae in the Philippines. It further raises the number of recognized endemic species of Saurauia in the country to 57. Moreover, Saurauia longipedicellata Merr. is also rediscovered almost a century since it was first described. Following the International Code of Nomenclature for algae, fungi, and plants (Turland et al. 2017) (ICN), we here assign a lectotype among its syntypes to stabilize this name. Photos, taxonomical and ecological notes, including and an amended description, are also provided.

MATERIALS AND METHODS
Initial description of the plants were done in situ. Further description was made using dried herbarium and spirit specimens. Botanical illustrations of the new species and S. longipedicellata were created from photographs of living plants and specimens preserved in spirit. Morphological comparisons to similar species were made using herbarium specimens. Images of type specimens deposited in JSTOR Global Plants (continuously updated) were likewise analyzed. All vegetative characters were observed and recorded in the field and reproductive characters were based on fresh and preserved material. The amended description of S. longipedicellata was based on the original description and supplemented by the specimen vouchered by the first author. All specimens were vouchered using the Wildlife Gratuitous Permit: G.P. No. R-IX-03-2021 (New) granted by the Department of Environment and Natural Resources (DENR) Region IX. Herbaria abbreviations follow Thiers et al. 2020 (continuously updated

Etymology
The specific epithet abbreviata is derived from the Latin word "brevis" (short) in reference to the very short or shortened inflorescences and flower dimensions of the new species-character combinations which are very rarely observed among Philippine Saurauia species.

Phenology
Flowering from July to August; fruiting from January to February.

Proposed Conservation Status
There were only around 20-30 individuals seen in the type locality, along the stream. There is an adjacent forested area, but it has not yet been fully explored. Considering the sampling limitations and the lack of con-crete data to establish a putative assessment, we propose it to be listed under the Data Deficient (DD) category (IUCN Standards and Petitions Committee 2019).

Notes
S. abbreviata bears some similar characters to S. bakeri Merr. and S. clementis Merr. in terms of its dense indumentum in its branchlets, abaxial lamina, inflorescence, sepals, and locule-style number (S. clementis also has a uniformly distributed setae on its adaxial surface). However, both S. bakeri and S. clementis are clearly distinct from S. abbreviata by bearing smaller leaves, fewer lateral nerves, distinctly long peduncled inflorescence, and larger flowers. Likewise, the new species is somewhat close to S. elmeri Merr. by its much-reduced inflorescence, however the leaf and flower characters of the new species cannot be mistaken.
The knowledge gap, not only about the Zamboanga region but also the Philippine flora, is not yet fully resolved and many genera still need urgent taxonomic attention. Majority are still only known from one or two collections (including S. lanaensis). Amending the description and finding the type population is integral to this step. Unfortunately, threat of habitat destruction, armed conflict, and climate change hinders conservation and taxonomic efforts. The habitat of the new species is likewise within the ancestral land of the indigenous people in Zamboanga. The Subanen people call S. abbreviata 'himag-puti' and is traditionally used as an ointment for wounds along with other Saurauia species found in the type locality.

Rediscovery and lectotypification of Saurauia longipedicellata Merr.
Saurauia longipedicellata Merr. is rediscovered after almost a century from the forest of the Municipality of Leon B. Postigo, growing sympatrically with S. abbreviata sp. nov. As part of the study towards a revision and improving the species definition of Philippine Saurauia, an amended description of the species is provided here. Moreover, no holotype had been assigned in the protologue of S. longipedicellata. Thus, we assume that all extant specimens bearing the collection BS 36897 Ramos & Edaño are syntypes. The specimen deposited at K in our opinion matches the current circumscription of this species and best represents this taxon. We therefore assign it as the lectotype following the ICN (Turland et al. 2017). The specimen from K shows consistent diagnostic characters with respect to the rediscovered population as vouchered by KRFM (KRM 0016) and the original description (i.e. glabrous branchlets and leaves, axillary and cauline positioned inflorescences with very long pedicels). All the remaining extant specimens with the same collection number of this species are therefore treated as isolectotypes. Merr., Philipp. J. Sci. 20, 1922: 407 (Figures 4, 5).

Notes
S. longipedicellata is unique and strongly characterized by being entirely glabrous (Merrill 1922). The specific epithet pertains to its long pedicels-the strongest diagnostic characteristic of the taxon. However, upon closer examination, it appears that there are (very) sparse minute warts and/or scales present in localized areas of the plant (at least for the vouchered specimens). But these sparse minute warts or scales needs a magnifying tool to confirm presence and cannot be easily discerned especially in fresh specimens.
Notably, these sparse minute warts and scales present in localized areas of the plant may have been a derived character from the reduction of the setae. The sparse warts are more visible abaxially as compared adaxially on leaves. The pedicels of cauliflorous fascicle are attached to lignified tubercles. The outer sepals are thicker and more rigid compared to the inner sepals which are somewhat petaloid. The style and locule number is 3 (very rarely 4). Nevertheless, all other characters mentioned in the protologue especially that of the long pedicels of both the inflorescence and infructescence of S. longipedicellata is similar for the Zamboanga population.

Ecology
The newly rediscovered population of S. longipedicellata Merr. was found in the same locality as S. abbreviata, sp. nov. Merrill noted that the type population of this taxon was collected in Zamboanga, district of Malangas, lowland forest along streams. Similarly, the rediscovered population of Saurauia collected by the first author were growing in the same ecological conditions, and it has been observed that all other species of Saurauia present in the area prefer the same habitat. At present the habitat preference and ecology of Saurauia species in the Philip-pines is not well understood. Thus, a comprehensive ecological study for Saurauia is recommended to aid future research in this poorly studied genus.

Proposed Conservation Status
Though endemic, the difficulty to conduct fieldwork in the areas of extant populations cannot confidently designate a putative conservation status of this species. We thus temporarily assign it as Data Deficient (DD) (IUCN Standards and Petitions Committee, 2019). ers involved in this study. We also thank the comments and suggestions of the reviewers that contributed to the improvement of this manuscript.