Abstract. Biag RD, Alejandro GJD. 2020. Short Communication: Rediscovery of Psychotria species, subspecies and varieties collected in the 1990s and new records of Antirhea benguetensis (Elmer) Valeton and Ixora longifolia Smith (Rubiaceae) in Northern Sierra Madre Natural Park, Luzon, Philippines. Biodiversitas 21: 4524-4535. Tagged as the “last great forest” for it possesses the widest remaining tropical rainforest in the island of Luzon, the Northern Sierra Madre Natural Park (NSMNP) in the province of Isabela is worth-conserving. Owing to the species richness and high levels of endemism in the said area, it was identified as a key biodiversity area for conservation and protection. After a botanical exploration in the park conducted from April to August 2019, 89 Rubiaceae species were found dominated by the genus Psychotria. These Psychotria species were then separated from other genera and were morphologically examined and eventually identified. This study, therefore, primarily aims to provide the list of Psychotria species that were collected long before, particularly in the 1990s and still exist in NSMNP continuously battling against the catastrophic activities within the forest. Eight Philippine endemic Psychotria species and varieties were recollected. As to their current conservation status following IUCN criteria, we herein propose these species, except for Psychotria pubilimba, to be treated as Data Deficient (DD) since there is lack of distributional data for these species. Additional surveys are to be conducted on the areas where these species were previously collected. In this way, information on population size and threats to the species can also be obtained. P. pubilimba is restricted to Cagayan and Isabela. Only one mature individual has been found; hence, a Narrow Endemic Species (NES). Being an NES, it was then assessed as Critically Endangered (CR) based on IUCN rules. It is also worth noting that new records of Antirhea benguetensis and Ixora longifolia species were found in the park, particularly in Divilacan, Isabela. The former has been regarded as Luzon endemic, known to be distributed only in Benguet, Ilocos Sur, Rizal, and Bataan. The latter, on the other hand, is mostly distributed in the provinces of Visayas and Mindanao, and only Masbate and Palawan for Luzon. Moreover, this flora has been recorded in other parts of the world like China, India, Myanmar, Indonesia, Malaysia, and Vietnam.

A new distribution record of Psychotria catanduaniensis Sohmer & A.P. Davis is reported. It was last observed 91 years ago, but as reported here a single individual of this threatened species was recently found in a coastal area in Palanan, Isabela, Luzon, Philippines. The species is characterized by large polymorphic leaves and a terminal, paniculate, sessile and trichotomous inflorescence. An emended description of the species, particularly focussing on its bracts, bracteoles and flowers which are lacking in the type material and not previously studied, morphological comparison with allied species and its current conservation status are also provided.

The Northern Sierra Madre Natural Park (NSMNP) in Isabela, Philippines holds the record of being the widest remaining tropical rainforest on the island of Luzon. However, this park remains underexplored in terms of its flora. A few botanical studies have been conducted but were particularly focused on the general floristic diversity of the area. No botanical studies have been done yet concentrated on a particular plant family. Species conservation and protection could be more resounding if attention is given to a particular group of plants like the very diverse Rubiaceae family. Hence, an initial checklist of Rubiaceae species in NSMNP is provided with accounts in their richness, distribution, and conservation status. The botanical exploration was conducted in April–August 2019 in NSMNP, specifically in the coastal areas – namely, Palanan, Divilacan, and Maconacon – and a non-coastal zone, Cabagan. In total, 52 Rubiaceae species were recorded belonging to 23 genera and representing 15 tribes of the family. The number of species constitutes about 9.72% of the total number of species in the country. The most specious among the tribes belong to Psychotrieae (9), followed by Spermacoceae (8), Naucleeae and Urophylleae (6), and Coffeeae (5). Of these species, 31 are Philippine endemic, while two are considered narrow endemic to the province. As regards their conservation status based on the International Union of Conservation of Nature (IUCN) list of threatened species, one was assessed as critically endangered (CR) and another one as endangered (EN). Further, two more species were recognized as highly threatened (HT), being CR species, and two other species were assessed as vulnerable (VU) based on the Updated National List of Threatened Philippine Plants and Their Categories found in the Department of Environment and Natural Resources (DENR) Administrative Order No. 2017-11.

Abstract. Biag RA, Alejandro GJD. Diversity, distribution, and conservation status of Rubiaceae species in Peñablanca Protected Landscape and Seascape, Luzon, Philippines. Biodiversitas 22: 3627-3636. Peñablanca Protected Landscape and Seascape (PPLS) is the largest protected area (PA) in the province of Cagayan, Luzon, Philippines. As part of the Sierra Madre Mountain Range and being contiguous with the Northern Sierra Madre Natural Park, there is no doubt that this PA would display species endemism and richness. Hence, botanical surveys through purposive sampling in seven barangays/districts were conducted in the PPLS to determine the species diversity and distribution of Rubiaceae. This study also aims to identify the endemic species and determine their conservation status. Forty-two species of Rubiaceae belonging to 19 genera and 13 tribes were documented in the current study. The most species-rich tribes are Spermacoceae (9 sp.), followed by Psychotrieae (7 sp.), Pavetteae (6 sp.), Naucleae (5 sp.), Ixoreae (4 sp.), Aleisantheae (2 sp.), Mussaendeae (2 sp.), and Vanguerieae (2 sp.). The rest of the tribes, i.e., Augusteae, Coffeeae, Gardenieae, Knoxieae, and Morindeae, are represented by a single species. Minanga, Nabbabalayan and Sisim harbor the most species. Results show that 19 Philippine endemic species are thriving in the PPLS. Of these, four are threatened species; one is near threatened, three being least concern, two as data deficient, and the rest were not evaluated.