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| Psychotria caraballoensis Pajarillaga, Ordas & Moran, in Pajarillaga, Ordas, Odulio, Venturina et Moran, 2025. |
Abstract
In this paper, we describe and illustrate Psychotria caraballoensis, a new endemic species from the Caraballo Mountain Range, Luzon, Philippines. It is allied to the Subalpina species group sensu Sohmer and Davis (2007), and resembles Psychotria sohotonensis. However, it is distinct by its greater number of lateral veins, leaf blades drying khaki to dark brown, inflorescences/infructescences with axes branching into verticillate or oppositely branched cymules, puberulous flowers with longer corolla lobes, smaller and globose to subglobose fruits, and ruminate endosperms. It is one of few species of Philippine Psychotria documented to have both long and short-styled flower morphs. The conservation status of this species is proposed as ‘Endangered' (EN), due to its restricted range and the presence of anthropogenic threats in the area.
Keywords: distylous, montane, Nueva Vizcaya, Philippine flora, Psychotrieae, taxonomy
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| Psychotria caraballoensis sp. nov. (A) Flowering individual, (B) stipules and leaf attachment, (C) short styled flower, (D) short styled flower front view, (E) corolla, (F) opened corolla, (G) calyx and hypanthium of short styled flower, (H) infructescence, (I) fruit, (J) fruit cross-section showing pyrenes, (K) pyrenes (left – dorsal view, right -ventral view). Scale bars – A = 1 cm, B–K = 1 mm. Illustrated by Propa Joy S. Venturina. |
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| Psychotria caraballoensis sp. nov. (A) Leaf attachment and stipules, (B) leaves with abaxial side (top) and adaxial side (below), (C) inflorescence, (D) long-styled flower (pin), (E) short-styled flower (thrum), (F) infructescence, (G) fruits. Scale bar A–C = 1 cm, D–G = 5 mm. Photographs A and C–F by Lyle Christian P. Santiago and B and G by Sarah Grace S. Zamudio. |
Psychotria caraballoensis Pajarillaga, Ordas & Moran sp. nov.
Diagnosis: A species closely resembling Psychotria sohotonensis Sohmer and Davis, but distinct by its leaf blades with numerous lateral veins (14–19 versus 10–14) drying khaki to dark brown (versus dark brown to dark olivaceous brown), inflorescences/infructescences with axes that further branch into verticillate or oppositely branched cymules (versus axes terminating into shortly branched cymules), puberulous flowers (versus glabrous) with longer corolla lobes (2.7–3.2 mm versus 1.5 mm), smaller (4.0–5.5 mm versus 8–9 mm) globose to subglobose fruits (versus ellipsoid-globose), and ruminate endosperms (versus entire). Additionally, dimorphic flower morphs with long and short styles were observed.
Etymology: This species was named after the Caraballo Mountain Range of Nueva Vizcaya Province, where it was discovered.
Jenifer D. Pajarillaga, Jorge Anton D. Ordas, Eiana Joshier A. Odulio, Propa Joy S. Venturina and Cecilia B. Moran. 2025. Psychotria caraballoensis (Rubiaceae), A New Species from northern Luzon, Philippines. Nordic Journal of Botany. DOI: doi.org/10.1002/njb.05026 [14 November 2025]
