Psittacanthus job-kuijtii F. J. Roldán, Carmona & J. S. Murillo sp nov.

Figs 1, 2, 3

Type

COLOMBIA – Antioquia • Municipio de Anorí, vereda La Providencia, sector Tierra Feliz; 7°18’4.464”N, 75°03’44.712”W; 600 m; 19 Jul. 2018; fl.; David et al. 6371; holotype: HUA [HUA 0074954].

Diagnosis

Psittacanthus job-kuijtii differs from the remaining species in the genus by the combination of the following characters: percurrent shoots; leaf blades ovate to broadly lanceolate, base truncate to rounded, margins revolute and adaxially extending toward the petiole, forming a V-shaped projection, apex attenuate to acuminate; inflorescences usually double triads, rarely triple triads, or a monad with two triads (all variations were observed in the holotype); flowers 4–5 cm long in pre-anthesis; petals red to orange in the proximal and medial portions and yellow distally with a deltoid, fleshy basal ligule bearing minute papillae, 1.8–2 mm long; stamens dimorphic, staminal hairs absent. Psittacanthus job-kuijtii is similar to P. peronopetalus, but differs from it by having usually double (rarely triple) triads (vs umbels of four triads), and flowers opening at anthesis with petals recurved for about 2 cm (vs flowers opening only at the apex, with petals recurved for no more than 2 mm).

Description

Hemiparasitic shrub. Haustorium not seen. Branches percurrent, slightly flattened when young, terete when mature, striate. Internodes 2.9–10.4 cm long, 2.1–4.8 mm diam., glabrous; nodes not swollen. Leaves opposite; petiole 3.2–12.4 mm long, 1.8–2.9 mm diam., canaliculate adaxially, terete abaxially; leaf blades ovate to broadly lanceolate, 8.2–23 × 2.7–10.7 cm, coriaceous, base truncate to rounded, with revolute margins adaxially extending towards petiole (V-shaped), apex attenuate to acuminate, margin entire, glabrous on both surfaces; venation brochidodromous, obscure, central vein prominently raised and striate, secondaries impressed, obscure. Inflorescences axillary, usually composed by double triads (rarely triple triads, or one monad with two triads), pendulous, axes pale green, glabrous, inflorescence peduncle 7–13.6 mm long, 0.9–1.1 mm diam., bracts absent; triad peduncle 4.2–8.2 mm long, 0.7–0.9 mm diam., 1 bract deltoid per triad, 0.7–1 mm long, 1–1.1 mm wide at base, cupular pedicels pale green, 6.2–8.4 mm long (without including the cupular portion), ca 0.5 mm diam., cupule ca 0.4 mm long, 1.8 mm wide; bracteole fused to the cupule, deltoid, 0.5–0.8 mm long, 0.8–1.3 mm wide at base. Flower tubular, straight, flower buds 4–5 cm long in pre-anthesis, 1.8–2.5 mm diam. in proximal portions, 1.3–1.6 mm diam. towards the distal portion in sicco; 6 - merous. Petals glabrous, red to orange in proximal-medial portions, yellow in distal portions, recurved distally at anthesis (close to 2 cm), medial and proximal portions remain straight, isomorphic, narrowly oblong, 4.8–5 cm long, 0.8–1 mm wide, apex acute, proximal and medial portions of petals with vermicular appendages along each margin, post-staminal hairs absent, basal ligules, 1.8–2 mm long, deltoid, fleshy, minutely papillate, placed to ca 1.7 mm above the base of the petal. Stamens epipetalous, dimorphic; free portion of filaments 10–12 mm long in the shortest series, 13–14 mm long in the longest series, both terete, anthers dorsifixed, oblong, with a pair of lobes at the base, 4 – loculate, 2.8–3.8 mm long, 0.8–0.9 mm diam. Ovary 1.8–2.3 mm long, 1.2–2 mm diam., cupuliform, pale green; calyculus ca 0.7 mm long, conspicuous, truncate-notched to dentate, pale green; style 4.5–4.7 cm long, 0.2–0.4 mm diam. in proximal portion, straight, white to light pink proximally and green in medial to distal portions; stigma 0.5–0.6 mm diam., capitate, green. Fruit elliptic, smooth, ca 12 mm long, ca 8 mm diam., purple, black when mature, calyculus persistent; seed ovoid, ca 9 × 5 mm, endosperm 6 – lobed, prismatic compound, embryo not seen.

Distribution

Psittacanthus job-kuijtii has been collected in Anorí and Amalfi, two neighbouring municipalities in the eastern portion of the Antioquia Department, Andean Region, Colombia.

Habitat and ecology

It occurs in a tropical moist / wet transition zone in Anorí and in moist premontane forest in Amalfi, between 400 and 1100 m a. s. l. (Fig. 3). The species has been reported parasitizing an unidentified species of Melastomataceae.

Phenology

Psittacanthus job-kuijtii was collected with flowers in July, September, and December, and with fruits in December.

Etymology

The epithet honours Job Kuijt (1930–2024), a plant taxonomist and mistletoe specialist who made significant contributions to the study of diverse parasitic plant groups, particularly mistletoes. He was also the author of the monograph on Psittacanthus (Kuijt 2009).

Preliminary IUCN conservation assessment

Psittacanthus job-kuijtii grows in well-preserved forests and it is known from collections made at four neighbouring localities (Fig. 3); these areas are constantly threatened by deforestation, agricultural expansion, and gold mining (Soejarto 1975; Ariza Cortés et al. 2009). According to our data, this species has an Extent of Occurrence (EOO) of 58.3 km 2 and an Area of Occupancy (AOO) of 16 km 2. Based on this information, we hypothesize that the EOO, AOO, and the extent and quality of the habitat of P. job-kuijtii are in continuous decline; therefore, we suggest its preliminary placement in the “ Endangered ” category: EN B 1 ab (i, iii) + 2 ab (ii, iii).

Notes

This new species belongs to the genus Psittacanthus based on its dorsifixed anthers (Kuijt 2009, 2014). The most morphologically similar species to P. job-kuijtii are P. hamulifer Kuijt, P. peronopetalus Eichler, and P. smithii Kuijt, with similarities in their vegetative traits such as plant habit and leaf shape and size. However, the inflorescence morphology, the flower length of each species, and the length of the basal ligule, distinguishes P. job-kuijtii from similar taxa (Table 1).

Inflorescence architecture is a primary diagnostic feature for delimiting species and identifying specimens within Psittacanthus. This structure comprises two types of peduncles (the inflorescence peduncle and the triad / dyad peduncle), floral pedicels, and the flowers themselves (Kuijt 1981, 2009). However, most of these inflorescences possess a three-dimensional arrangement that rarely survives the drying and pressing process intact. Because components are easily detached, the reconstruction of herbarium material often relies on analysing the scars left by adjacent parts to interpret the original structure (Kuijt 2009). Based on our examination of the holotype (David et al. 6371, HUA), we observed that the inflorescence of Psittacanthus job-kuijtii typically consists of a peduncle supporting two triads. A detailed analysis revealed structural variations or atrophies, such as the presence of three triads or two triads accompanied by a monad (as mentioned in the species description). These deviations likely reflect developmental plasticity or environmental influences during ontogeny; however, such morphological instabilities remain largely underreported for the genus. Nevertheless, the predominant inflorescence ground plan remains a stable and reliable trait for the taxonomic diagnosis of Psittacanthus species.

Psittacanthus job-kuijtii is known from four collections, with poor information about its host range and haustorium morphology. Field expeditions in adjacent regions of Anorí and Amalfi would reveal further data about the host range and verification of the conservation status proposed here.

Moist forest ecosystems of Amalfi and Anorí stand out as areas of exceptional floristic diversity and abundance (Ariza Cortés et al. 2009; Idárraga-Piedrahita and Callejas-Posada 2011). A study conducted in a wet premontane forest, transitioning to premontane rain forest in Amalfi documented high family-level plant richness, recording more than 150 species with a notable representation of Lauraceae, Melastomataceae, Rubiaceae taxa, and epiphytic plants (Ariza Cortés et al. 2009). Similarly, the moist forest ecosystem of Anorí (referred to as “ humid forest ” in Kor and Diazgranados 2023), has been identified as one of the ten priority areas for the conservation of useful plants in Colombia, due to the high species richness of this region (Kor and Diazgranados 2023). Furthermore, recent taxonomic discoveries in Costaceae, Magnoliaceae, Melastomataceae, and Selaginellaceae from both Amalfi and Anorí highlight that the plant diversity of these localities remains poorly known (Murillo-Serna et al. 2022; Maas et al. 2023; Serna-González et al. 2024; Valdespino et al. 2024). These findings underscore the need for further sampling efforts and the implementation of conservation strategies in both municipalities, which are increasingly threatened by landscape fragmentation and logging pressures (Soejarto 1975; Ariza Cortés et al. 2009).

Additional specimens examined (paratypes)

COLOMBIA – Antioquia • Amalfi, Vereda La Gloria, 35–37 km NE de Amalfi, en la vía Amalfi-Vetilla, sobre Melastomataceae; 7°05’N, 74°56’W; 950–1100 m; 9 Dec. 1989; fr.; Callejas et al. 9218; HUA [HUA 69823], NY • Anorí, Valle del río Anorí, between Dos Bocas & Anorí, Vic. Planta Providencia, 26 kms S & 23 kms W (Air) of Zaragoza; 7°13’N, 75°03’W; 400–700 m; 1 Dec. 1974; fl.; Denslow 2517; HUA [HUA 9069] • Anorí, Vereda “ La Esperanza ”; 7°11’04”N, 75°01’53”W; 800–900 m; 17 Sep. 1999; fl.; Tuberquia et al. 1167; JAUM, MEDEL [MEDEL 70084].