Piper quinchasense M.A.Jaram., 2023

Jaramillo, M. Alejandra, Rodriguez-Duque, Dayro & Escobar-Alba, Magda, 2023, A new species of Piper (Piperaceae) with peltate leaves from Serrania de las Quinchas, Colombia, PhytoKeys 227, pp. 9-24 : 9

Piper quinchasense M.A.Jaram. sp. nov.

Type.

Colombia. Boyacá: Otanche, vereda Las Quinchas, Sector La Y, Finca Lote Terreno , 5°48'17"N, 75°15′24"W, 1210 m, 17 Mayo 2022 [fl], M. A. Jaramillo et al. 1807 (holotype: HUA; isotypes: UPTC, UMNG-H). Figs 1 - 3 .

Description.

Piper quinchasense is similar to P. parianum , it differs from the latter in having all leaf blades peltate (vs. leaves deeply lobed to peltate), and inflorescence peduncle 4-5 cm long, (vs. peduncle 1-2.7 cm long).

Shrub, 3 m tall, branched in the upper portion only, exhibiting stilt roots (Fig. 2C ). Internodes 5-10 × 2.5-4.6 cm, green when young and becoming brown when maturing, tomentose, idioblasts not evident. Prophylls not seen. Petioles 4.5-8.5 cm long, vaginate the entire length (Figs 2D , 3J ), tomentose, idioblasts evident. Leaf blades (28) 35-49 × 7.5-19 cm, oblong-lanceolate, base obliquely-peltate, asymmetric to truncate, peltate, petiole inserting 2.5-10.5 cm from the margin, on the adaxial surface leaf blade is depressed and umbonate above petiole insertion (Fig. 2E ), blade medially asymmetric, apex long attenuate, green on the adaxial surface and green-silver on the abaxial surface when alive (Fig. 2E, F ), coriaceous, chartaceous when dry, drying dark maroon on the adaxial surface and ochre on the abaxial surface, glabrous with visible idioblasts on the adaxial surface (Fig. 3K ), sparsely tomentose on the blade and veins densely tomentose on the abaxial surface (Fig. 3I ), eciliate, margin folds towards the abaxial surface appearing to form irregular spaced teeth; pinnately nerved to the distal third, 4-6 pairs of secondary veins, curved and ascending, diverging in angles that decrease towards the apex (from 80-30 degrees) and spacing slightly decreasing towards the base, tertiary veins forming areoles 1.2-1.8 × 0.5-1 cm, rectangular and not uniform in size, perpendicular to secondary nerves, nerves not impressed on the adaxial surface, elevated on the abaxial surface. Inflorescences a simple spike, terminal, pendulous; peduncle 4.5-5 cm long, tomentose, green, idioblasts not evident; rachis length in flower 12-19 cm × 3-4 mm, rachis length in fruit 25-27cm. Floral bracts cucullate, sagitate from above (Fig. 3F ), 1.8-2.3 × 0.9-1.0 mm, pellucid dotted, pedicel fimbriate on the distal portion (Fig. 3E ), forming bands around the spike (Fig. 3B ). Flowers sessile with 4 stamens (Fig. 3C ), filaments 0.25-0.40 mm long, anthers 0.3-0.6 × 0.16-0.26 long, with connective glabrate, longitudinally dehiscent, dithecous (Fig. 3D ), ovary four carpellate, four stigmas sessile, not persistent in fruit, 0.4-0.5 mm long (Figs 2B , 3G ). Fruits obpyriform, 2.1-2.4 × 1.0-1.6 mm, glabrous, green when alive, brown when dry (Fig. 3G ). Seeds smooth, pellucid dotted, obpyriform, 1.9-2.1 × 1.0-1.3 mm, glabrous, brown when dry (Fig. 3H ).

Phylogenetic relationships.

Piper quinchasense belongs to the Macrostachys clade (Fig. 4 ). A group of shrubs and treelets reaching 7-8 (15) m tall, petioles sheathing above the middle or throughout their length, pinnately nerved leaves, mostly larger than 30cm long, inflorescences mostly pendulous (erect in some species), and flowers forming bands around the spike ( Jaramillo et al. 2008). Species with peltate leaves have evolved independently in clades Macrostachys , Pothomorphe , Oxodium (= Schilleria , Callejas 2020) and Ottonia . Peltate leaves are known to occur in the two large genera of Piperaceae : Piper and Peperomia . They are more common in plants that grow in the shade of humid tropical forests ( Wunnenberg et al. 2021). There is still much to learn about the functional morphology and anatomy of Piper species with peltate leaves.

Distribution and habitat.

The species is only known from the type locality Serranía de las Quinchas (Fig. 1 ). Piper quinchasense is a tall shrub in the understory of very humid forests; it often grows near streams. The occurrence of stilt roots (Fig. 2C ), a character not commonly seen in Piper , suggests it is adapted for flooded areas near watercourses. It also is a very resilient plant that will produce adventitious roots if tumbled and it will continue growing, or even resprout, from a fallen leaf. Resprouting is common among shade-tolerant Piper ( Lasso et al. 2009).

Phenology.

Flowering specimens were collected in March, and May. Fruiting specimens were collected in October.

Etymology.

The epithet quinchasense, refers to Serranía de las Quinchas, the type locality for this species. According to locals, Quinchas derives from the indigenous groups “Quinchos” that inhabited the region.

Conservation status.

This species is known only from one population in the type locality (Fig. 1 ). The extent of occurrence (EOO) of 8 km2 and area of occupancy (AOO) of 8 km2 are very small. The locality is under threat of disappearing for the extension of agricultural and mining activities ( Rodríguez-Duque et al. 2021), which suggests it is Endangered [EN B1a]. Serranía de las Quinchas was declared a Regional Park in 2008; since its creation, the park extension has been reduced by 20% as the buffer zones were eliminated. Furthermore, the constant threat of coal mining makes the locality highly exposed to deforestation.

Additional specimens examined.

Colombia. - Boyacá: Otanche, vereda Las Quinchas, Sector La Y, Finca Lote Terreno , 5°48'17"N, 75°15′24"W, 26 October 2022, [fr] M. A. Jaramillo et al 1939 (HUA, UMNG-H) ; Boyacá: Otanche, Parque Regional Natural, Serranía de las Quinchas , 5°48′45.5"N, 75°15′22.2"W, [st] 14 June 2021, Magda Escobar-Alba et al. 489 (UPTC); Parque Regional Natural Serranía de las Quinchas, vereda las Quinchas, Finca Chorro Negro, 5°49′7.2"N, 75°14′57.3"W, [fl] 3 March 2022, Magda Escobar-Alba et al. 762 (UPTC) .

Notes.

Piper quinchasense is a handsome species that differs from related Macrostachys taxa in having long lanceolate-oblong leaves. It is morphologically similar to P. parianum from which it differs in having mononomorphic leaves (all of them peltate) vs. leaves dimorphic, some peltate and others are deeply lobed. P. parianum is only known in the isolated cloud forests of "Peninsula de Paria", a region located in the eastern portion of Coastal Cordillera in the extreme northeast of Venezuela. The flora of Paria Peninsula is characterized by the high occurrence of endemic species ( Steyermark and Agostini 1966; Meier 2011) and several types of vegetation communities ( Beard 1946). The flora of this region has many affinities to plants of Trinidad and Tobago ( Selaginella hartii Hieron.; - Selaginellaceae ; 5 Turrill - Acanthaceae : sensu Baksh-comeau et al. 2016), and the forests of the Northeastern sector of Guayana Shield in Venezuela and the Guianas (e.g., Besleria insolita C.V. Morton - Gesneriaceae ; Meier 2011). Serranía de las Quinchas, on the other hand, has the most floristic affinities with the Chocó region (e. g. Dimerocostus cryptocalyx N. R. Salinas & Betancur, Salinas and Betancur 2004). The regions have similar habitats driven by high precipitations despite their divergent biogeographical affinities.

A key to species of Neotropical Piper with peltate leaves is presented below.

New status

While preparing the key for peltate Neotropical Piper , we realized some species deserve new status. New status and new names are proposed for two species.

Figures

Figure 1. Geographic distribution map of Piper quinchasense M. A. Jaram.

Figure 2. Piper quinchasense M. A. Jaram. A habit B magnified view of inflorescence C stilt roots D sheathing petiole E adaxial surface of leaves F abaxial surface of leaves and inflorescence. Photographs by D. Rodriguez-Duque.

Figure 3. Piper quinchasense M. A. Jaram. A sympodial branch, showing both the abaxial and adaxial surface of the leaves B magnified view of inflorescence C floral diagram D anther E floral bract, abaxial view F floral bract view from above G fruit H seed I magnified view of leaf abaxial surface J sheathing petiole K magnified view of leaf adaxial surface. Illustration by Ariadna Valenzuela, based on M. Escobar-Alba 764, and photographs by D. Rodriguez-Duque.

Figure 4. Phylogenetic relationships of Piper quinchasense M. A. Jaram. and 14 species of Neotropical Piper with peltate leaves (in bold). Topology based on Maximum likelihood analysis of nrITS sequences. Numbers on branches are maximum likelihood bootstrap support values (> 90 %).