Lacistema morrocoensis J.M. Vélez & L. Marinho, 2025

Puerta, Jorge Mario Vélez & Marinho, Lucas Cardoso, 2025, Lacistema morrocoensis, a new Colombian species of Lacistemataceae, and the extension of L. macbridei distribution to the country, Phytotaxa 700 (3), pp. 279-287 : 280-285

Lacistema morrocoensis J.M. Vélez & L. Marinho , sp. nov. ( Figures 1 , 2 , 3 )

Type:— COLOMBIA. Vaupés: Mitú, corregimiento departamental de Pacoa, Comunidad de Buenos Aires sobre margen derecha del río Cananari, afluente del río Apaporis, en cercanía a Jirijirimo. Vegetación de arbustal en la cima de Cerro Morroco, sobre afloramiento rocoso, 0°8’1’’N 70°56’36’’W, 550 m. s.n.m., 12 November 2017, fl., D. Cárdenas, N. Marín, A. Súarez & R. Sánchez 49232 (holotype: COAH 99218!).

Diagnosis:— Lacistema morrocoensis is similar to L. aggregatum (P.J. Bergius 1772: 131) Rusby (1907: 447) from which it can be differentiated by the small (≤ 8.3 × 3.3 cm) and coriaceous leaves (vs. ≥ 8.5 × 3.5 cm and chartaceous in L. aggregatum ) with convex to rounded apex (vs. acute or apiculate apex), 3–4(–5) pairs of secondary veins (vs. 5–6), black dots on the adaxial leaf surface present (vs. absent) and 1, rarely 3, spikes per axil (vs. 2–8 per axil).

Description:— Shrubs up to 3 m tall when growing in rock fields, or treelets up to 7 m tall when growing in the forests at the base of the outcrops, branches glabrous; terminal stipules 5–6.5 mm long, with simple and adpressed trichomes in the midvein of the abaxial surface. Leaves alternate, entire; petioles 3.5–8 mm long, blackish in sicco, glabrous or with simple trichomes, sparse, adpressed. Leaf blade 3.7–8.3 × 1.3–3.3 cm, coriaceous, obovate to broadly elliptic, the apex convex to rounded, margin entire, slightly revolute, the base attenuate, dark-green with light-green veins when fresh, shiny, discolors when dried, adaxial surface cream-brownish with small black dots densely arranged, abaxial surface brownish, glabrous. Venation: midvein plane adaxially, prominent abaxially; secondary veins in 3–4(–5) pairs, strongly impressed adaxially, plane abaxially, arched near the blade margin, strongly arched near the apex. Spikes axillary, 1 rarely 3 per axil, color not seen, 0.6–12 mm long; rachis with trichomes; basal bracts 0.4–0.5 × 0.8–1 mm, naviculate, glabrous, margin erose; bracteoles 2, 0.3–0.4 × 0.08–0.1 mm, linear, frequently falcate, glabrous, the apex acute, the margin entire, the base truncate. Flowers monochlamydeous, color not seen; sepals 5, ca. 0.4 × 0.2 mm, broadly elliptic, the apex convex, the margin erose; stamen 1, 0.75–0.8 mm long, fused to the nectary; filament slightly curved, glabrous, anthers ca. 0.08 mm long, extrorse, connective thickened, 0.3–0.4 mm wide; nectary 4–lobed, fleshy; gynoecium 0.35–0.5 mm long, ovary superior, 0.2–0.3 mm long, 3-carpellate, ovule 1 per locule, spheroid, glabrous, styles 0.15–0.2 mm long, glabrous, styles very short, stigmas 3, subsessile. Capsules 7–9 mm long, ovoid, narrow at the base, red when mature, shiny, glabrous. Seed not seen.

Additional examined specimens (Paratypes):— COLOMBIA. Amazonas: Corregimiento de La Pedrera, resguardo Indígena Curare–Los Ingleses , comunidad Curare , en bosque de tierra firme y catingas, 1°17’S 69°44’W, 100 m. s.n.m., 18 March 2004, fr., Z. Cordero-P. 460 ( COAH 71089 , COAH 71090 , COL 554387 ). Vaupés: En vegetación arbustiva sobre cerro Morroco, 0°7’43,2”N 70°56’38,2”W, 604 m. s.n.m., 26 February 2018, fr., D. Cárdenas et al. 49852 ( COAH 99187 ) ; ibid., D. Cárdenas et al. 49875 ( COAH 99178 ) ; Corregimiento de Pacoa, comunidad Morroco, subida al cerro Morroco , al frente de la comunidad, bosque primario poco intervenido, 0°8’15,7”N 70°56’47”W, 200 m. s.n.m., 28 February 2018, fl., J. Betancur et al. 21940 ( COAH 100576 ) .

Etymology and vernacular name:— The specific epithet refers to Cerro Morroco, one of the locations where the species was found. Morroco is also the name given to the local indigenous community. In the Barasano indigenous language, Lacistema morrocoensis is known as Cumuᵾ (Cárdenas-López et al. 2019).

Distribution and preliminary conservation status:— Lacistema morrocoensis is known from two localities in rocky outcrops ( Fig. 3 D-E) of the Guiana Shield in the departments of Amazonas and Vaupés, Colombia, between 100–550 meters above sea level, growing in shrub formations and surrounding forests ( Fig. 4 ). The preliminary conservation status of L. morrocoensis is here assessed as Critically Endangered (CR) based on an extent of occurrence less than 88 km 2 and an area of occupancy minor than 8 km 2 [B1 + B2bi,ii,iv] ( IUCN 2012).

Taxonomic notes:— Lacistema morrocoensis belongs to the L. sect. Lacistema (“ Eulacistema ” in Chirtoiu 1918: 329), with a very short or practically no style and sessile or nearly sessile stigmas. The species can be recognized by the combination of small, coriaceous and glabrous leaves with convex to rounded apex, black dots on the adaxial surface, and 3–5 pairs of secondary veins, inflorescence 1, rarely 3, spikes per axil, flowers with stamens and gynoecium glabrous and stigmas very short.

Lacistema morrocoensis had been identified in the herbaria as Lacistema aggregatum , a widely distributed species of the family which belongs to the same section. The species can be distinguished from L. aggregatum by the small (≤ 8.3 × 3.3 cm) and coriaceous leaves (vs. ≥ 8.5 × 3.5 cm and chartaceous) with convex to rounded apex (vs. acute or apiculate apex), 3–5 pairs of secondary veins (vs. 5–6) and 1, rarely 3, spikes per axil (vs. 2–8 per axil).

Lacistema morrocoensis can be distinguished from the other species occurring in Colombia by the absence of indument on the branches and leaves (vs. with indument in L. macbridei and L. nena J.F. Macbride [1934: 392] ) and by the small leaves with convex to rounded apex (vs. large [13–23 × 6–8 cm] in L. krukovii Sleumer [1980: 184] ), with 3–5 pairs of secondary veins (vs. 8–12 pairs).

New records of Lacistema macbridei to Colombia:— In the Catalog of Plants and Lichens of Colombia ( Celis 2016), three species of Lacistema were recorded in the country: L. aggregatum , L. krukovii and L. nena , all of them with distribution in the Colombian Amazon. Besides L. morrocoensis , we also include the occurrence of L. macbridei in Colombia, at the Putumayo Department. Lacistema macbridei can be recognized by the pubescent branches, large stipules, leaves with secondary and tertiary veins strongly evident and pubescent, and very short style.

Specimens examined:— COLOMBIA. Putumayo: Municipio de Villagarzón , corregimiento La Castellana, vereda Alto Vides, Puente Rojo, Reserva Natural Selva Vides, en bosque primario intervenido, 0°53’2,90”N, 76°45’11,42”W, 490 m. s.n.m., 21 october 2021, fl., J. Betancur et al. 23300 ( COAH 119531 ) ; Finca Charco Azul, cuenca del río Vides , 0°53’37,86”N 76°45’18,76”W, 507 m. s.n.m., 18 november 2023, fl., J. M. Vélez et al. 8619 ( COAH 57481 ) .

Figures

FIGURE 1. Line drawing of Lacistema morrocoensis J.M. Vélez & L. Marinho. A. Branch with inflorescence. B. Detail of the abaxial leaf surface showing the black dots. C. Terminal stipule. D. Lateral view of flower. E. Top view of the flower (bract, one bracteole and three sepals removed); br = bracteole, se = sepals, n = nectary, st = stamen, gy = gynoecium. F. Bracteole. G. Sepal. H. Stamen. I. Gynoecium. J. Fruits. Illustration by L.C. Marinho:A–I from the holotype, J from D. Cárdenas et al. 49852.

FIGURE 2. Holotype of Lacistema morrocoensis J.M. Vélez & L. Marinho (D. Cárdenas et al. 49232) housed at COAH.

FIGURE 3. Photos of Lacistema morrocoensis J.M. Vélez & L. Marinho. A. Branch with mature fruits. B. Adaxial leaf surface. C. Mature fruits. D–F. Cerro Morroco, Vaupés, Colombia. Photos by A–C by Dairon Cárdenas, D e F by Mateo Coral, E by Nicolas Castaño.

FIGURE 4. Distribution map of Lacistema morrocoensis (circles), L. macbridei (triangles). The numbers above the icons represent a botanical collection.