Pinalia campanulata Saavedra & Pitogo, 2023

Saavedra, Aljohn Jay L., Pitogo, Kier Mitchel E. & Boos, Ronny, 2023, A new species of Pinalia (Orchidaceae) with bell-shaped flowers from the mossy forest of southern Mindanao, Philippines, Phytotaxa 626 (2), pp. 93-100 : 95-97

Pinalia campanulata Saavedra & Pitogo sp. nov. ( Figures 2 & 3 )

Type:— PHILIPPINES. Mindanao island: South Cotabato Province, Municipality of Lake Sebu, Allah Valley Protected Landscape , 1720 m elevation, 6.2179° N 124.6235°E, 19 August 2022. AJ Saavedra AJS 0001 (Holotype: PNH!)

Diagnosis:— The new species is related to Pinalia polyura (Lindl.) Kuntze in Ames (1905: 95) but with a much shorter inflorescence (1–4 vs. 10–14 cm) bearing fewer flowers (10–18 vs. up to 40), oblong-elliptic sepals and petals (vs. ovate- to triangular-lanceolate lateral sepals and cordate petals), trilobed labellum (vs. unlobed) that is weakly keeled (vs. bicarinate) and having a deltate callus on disc (vs. purple tubercle). The new species is also distinguished by its prominently campanulate flowers.

Description:— Epiphytic, semi-pendulous herb up to 50 cm long. Pseudobulbs branching, laterally flattened, 50–60 mm long, 11.4 mm wide above the middle, fleshy, partly covered with appressed sheaths up to 25 mm long, bearing 2–3 leaves. Roots long, slender, to 0.5 mm thick. Stems terete, covered with laxly spaced sheaths up to 20 mm long, internodes 40–70 mm long, getting longer distally. Leaves lanceolate, apex obliquely acute or subacute, glabrous, entire, 7–10 × 2.5–3 cm. Inflorescence 1 or 2, lateral near or at the apex of the pseudobulb, raceme, glabrescent, 10–40 mm long, dense bearing 10–18 closely-spaced flowers, peduncle 3–9 mm long; floral bracts ovate, acute, reflexed, 3.8 × 3.1 mm, greenish cream; Ovary with pedicel terete, glabrous, 3.4 mm long; Flowers resupinate, campanulate, not widely open, glabrous, crystal white, 6.8 mm long, labellum white with a shade of burgundy in basal half. Sepals oblong-elliptic, apex obtuse, 3-veined. Dorsal sepal 5–5.3 mm long, 2.4 mm wide. Lateral sepals 5–6 mm long, 2.6– 2.7 mm wide, mentum less prominent. Petals oblong, subacute, 3-veined, 6–6.2 mm long, 2–2.1 mm wide. Labellum slightly decurved, trilobed, 4 mm long, 3 mm wide between the apices of lateral lobes when flattened, single fleshy dentate callus on the disc, weakly keeled; lateral lobes prominent, erect, curving inwards to partly embrace column, ovate, rounded, outer margin slightly sinuate; mid-lobe porrect, 1.2 m wide, ovate, apex acute, margins erose. Column terete, partly curved, up to 2.1 mm long, burgundy; column foot 1.1 mm long, pale pink, with a burgundy warty protrusion at the base. Anther orbicular in front. Pollinia 8, obovoid, yellow, very small.

Distribution:— Philippines. Provinces of Sarangani and South Cotabato (Allah Valley Protected Landscape), southern Mindanao.

Habitat and Ecology:— Pinalia campanulata is known only from the mossy forest of the Busa Mountain Range between 1,550 and 1,750 m elevation in southern Mindanao. This small epiphytic herb often grows on moss-covered tree trunks at about 1.5–2.5 m above the forest floor, lower than most congeners growing in the area. During our threeyear extensive fieldwork, only five (5) individuals were recorded on the northern slope in South Cotabato (within the AVPL) and only one (1) individual on the southern slope in Sarangani. The flowers are often visited by leaf beetles ( Chrysomelidae ), which may be potential pollinators or predators of this new species.

Phenology:— Plants were observed flowering in April and August–September.

Etymology: —The specific epithet, campanulata, is reminiscent of the prominently bell-shaped flowers of this species that do not open widely. To our knowledge, the shape of P. campanulata flowers is quite unique among Pinalia species.

Conservation Status:— Pinalia campanulata is known only at two (2) sites in the Busa mountain range and is restricted so far to higher elevations (> 1,500 meters) despite our continued, extensive orchid surveys within the KBA 196 and neighboring Mount Matutum since 2019. Its habitat in Lake Sebu is within the AVPL, an initial component of the NIPAS and legally protected under the Philippine Republic Act No. 11038. However, legal protection of its habitat does not guarantee protection from the illicit collection of wild orchid populations, which have been documented within the mountain range ( Saavedra & Pitogo 2021; DENR 2022). Besides, the IUCN (2012) clearly states that the criteria are to be applied regardless of the level of conservation action done for the species. Since epiphytic orchids less likely exhibit microendemism in Philippine mountains, we expect new records of this species will likely come out from the relatively intact and unsurveyed montane forests of the neighboring mountain ranges of Kidapong, Daguma, Malibato, and Tampakan Highlands (ca.> 20,000 km 2). In view of this information, we proposed to have P. campanulata provisionally classified as Near Threatened following the IUCN Categories and Criteria version 3.1 (IUCN, 2012) until more empirical field data is available.

Discussion:— We assign P. campanulata to the section Polyura for having branching pseudobulbs and a shorter labellum than sepals, which is adorned with a dentate fleshy callus ( Ormerod et al. 2019). The new species superficially resembles the flowers of P. polyura but differs in many floral aspects, most notably the floral measurements and shape of the labellum. This new species is distinguished among the Philippine species of Pinalia sect. Polyura by its relatively much shorter inflorescence (1–4 cm vs. 3–17 cm in other species), larger flowers relative to inflorescence length (petal length/inflorescence length 0.15 vs. 0.01–0.11), and trilobed labellum with prominent lateral lobes that partly embrace the column. Floral measurements closely approach P. tomentosiflora Hayata (1912:137) but P. campanulata is easily distinguished by its glabrescent inflorescence and outside surface of sepals (vs. tomentose) and longer lip (3.8 mm vs. 2.5 mm) with a single deltoid callus on disc (vs. four linear discs). This new species is also distinguished by its prominently campanulate flowers.

Our discovery of P. campanulata underpins the importance of continuously doing field-based research in southern Mindanao. It is among the least biologically explored regions in the Philippines, owing to logistical difficulty, security issues, and bureaucracy that impede fieldwork in the area ( Pitogo & Saavedra 2021). These challenges are exacerbated by the general lack of expertise (e.g., field biologists, biodiversity scientists, and taxonomists) in the region. Despite these limitations, recent botanical studies in southern Mindanao have shown significant levels of diversity that need immediate scientific and conservation attention ( Saavedra & Pitogo 2021; Obemio 2022). Thus, we recommend more extensive surveys in the mountains/mountain ranges of Busa, Malibato, Daguma, Kidapong, Matutum, Tampakan Highlands, and Latian to address the knowledge shortfalls that limit our understanding of southern Mindanao’s biodiversity.

Figures

FIGURE 2. Colored photos of Pinalia campanulata Saavedra & Pitogo. A. Flowering plant. B. Inflorescence. C. Lateral view of the flower showing its campanulate shape. D. Column (with the pollinia, left). E. Labellum (flattened). F. Labellum with column (natural form). G. petals and sepals.

FIGURE 3. Pinalia campanulata Saavedra & Pitogo.A. Underside view of a flowering plant. B. Top view of labellum. C. Column (with the pollinia, left). D. Front view of flower. E. Lateral view of flower. F. Petals, sepals, and labellum (flattened). Illustrated by Larie Dianco.