Microlicia woodii R. Pacifico, Almeda & Fidanza, 2020

Pacifico, Ricardo, Almeda, Frank, Rodrigues, Lorena Julia Gali & Fidanza, Karina, 2020, Novelties in Microlicia (Melastomataceae: Microlicieae) from the Bolivian Cerrado, Phytotaxa 433 (3), pp. 225-234 : 226-230

Microlicia woodii R. Pacifico, Almeda & Fidanza , sp. nov. ( Fig. 1–2 and 3A )

Diagnosis:— Microlicia woodii can be recognized by its elliptic leaf blades that are 8–10 × 3.2–5 mm, glandular-punctate on both surfaces, petioles 0.2–0.4 mm long, rectangular and dorso-ventrally flattened, solitary 5–6-merous flowers, external and internal deciduous intercalycine eglandular trichomes ca. 1–2 mm long, pink petals, and dimorphic, bicolored polysporangiate anthers.

Type:— BOLIVIA. Santa Cruz: Santiago de Chiquitos [municipality of Roboré], Meseta de Motacú , 18º16’32’’S, 59º40’49’’W, 920 m, 25 October 2010, J. R. I. Wood 26947 & D. Villarroel (holotype: K!; isotypes: LPB, USZ-digital image!) .

Well-branched erect shrubs ca. 0.5 m tall. Branchlets quadrangular, glutinous, densely glandular-punctate, rarely sparsely covered with white gland-tipped trichomes ca. 0.3 mm long, internodes 2–3 mm long, nodes thickened and often covered with clusters of white gland-tipped trichomes 0.3–0.4 mm long, stem angles light green (when dry) and unwinged. Leaves spreading (when fresh), decussate, shortly petiolate, flat, not imbricate and ca. 2–3 times the size of the internodes; petioles 0.2–0.4 mm long, 0.4–0.6 mm wide, rectangular and dorso-ventrally flattened, blades 8–10 × 3.2–5 mm, elliptic, chartaceous, vivid green and concolored when fresh, becoming discolored with the adaxial surface darkened (when dry), base rounded, margin entire or slightly serrulate and shortly ciliate with apparently eglandular trichomes 0.3–0.5 mm long, bent inward, apex rounded to shortly acute, both surfaces densely glandular-punctate, 3- to inconspicuously 5-nerved from the base, veins impressed on the adaxial surface and slightly prominent on the abaxial surface, midvein stouter and becoming faint towards the leaf apex, lateral veins less conspicuous and becoming faint along the distal third of the blade, tertiary veins absent. Flowers 5–6-merous, solitary, apical, pedicels 1–1.5 mm long; hypanthia (at anthesis) 2.9–3.1 mm long, 2.8–3 mm wide at the torus, campanulate and cream-colored (when dry), externally glandular-punctate; calyx tubes ca. 0.3 mm long, with external and internal deciduous intercalycine eglandular trichomes ca. 1–2 mm long; calyx lobes (at anthesis) 1.7–2 mm long, 1.1–1.3 mm wide at the base, triangular, cream-colored (when dry), margin entire and glandular-punctate, apex rounded or acute terminating in an eglandular apical trichome ca. 0.4 mm long, externally glandular-punctate; petals 7.4–7.8 × 4.3–4.6 mm, obovate, pink, margin entire covered with sessile glands, apex rounded, adaxial surface glabrous, abaxial surface sparsely glandular-punctate; stamens 10–12, dimorphic: larger (antesepalous) stamens 5–6, filaments 4.3–4.5 mm long, pink, connectives ventrally prolonged 5.3–5.5 mm below the thecae, pink, appendages 1.4–1.6 mm long, yellow, apex truncate, thecae 2.0–2.2 × 0.6–0.7 mm (excluding the rostra), oblong, pink, externally corrugate (polysporangiate), rostra 0.6–0.7 mm long, white, the circular pores ca. 0.2 mm wide; smaller (antepetalous) stamens 5–6, filaments 3.9–4.1 mm long, pink, connectives ventrally prolonged 1.4–1.6 mm below the thecae, pink, appendages 0.2–0.3 mm long, yellow, apex rounded, thecae 1.7–1.9 × 0.7–0.8 mm long (excluding the rostra), oblong, yellow, externally corrugate (polysporangiate), rostra 0.4–0.6 mm long, the circular pores ca. 0.2 mm wide. Ovaries ca. 2 × 1.7 mm, globose, superior, glabrous, 3-locular; styles ca. 8.5 mm long, linear, pink, stigma punctiform. Loculicidal capsules 3.5–4.5 × 2.5–3.5 mm (when mature), ovoid, brownish (when dry), initially enveloped by the hypanthia, then tardily rupturing and flaking away with age, apex not exceeding the torus, dehiscent from the apex to the base, columella deciduous. Seeds not seen.

Additional specimen examined:— BOLIVIA. Santa Cruz: Santiago de Chiquitos [municipality of Roboré], Cerro de Mocatú, 18º16’35’’S, 59º40’49.8’’W, 936 m, 3 April 2009, J. R. I. Wood 26016 & P. Pozo ( K!, LPB, USZdigital image!).

Distribution, habitat, and phenology:— Microlicia woodii is probably endemic to the Meseta de Motacú in Santiago de Chiquitos, Santa Cruz, Bolívia ( Fig. 4 ). In that area, M. woodii occurs on rocky seasonally wet soils exposed to full sun, at elevations of 920– 936 m. It was collected flowering and fruiting in October and April.

Conservation:— The Santiago de Chiquitos region is included in the Reserva Municipal del Valle de Tucavaca (RMVT) which comprises an area of 2,623.05 km 2 that encompasses some 37% of the municipality of Roboré ( Robison et al. 2001). The RMTV aims to preserve the unique mountainous landscapes of Santiago de Chiquitos, Cerro Chochís, and Tucavaca Valley, protecting its springs, threatened species of plants and animals and archeological sites, besides developing tourism and carbon emission trading ( Robison et al. 2001). However, legal recognition and protection of RMTV is not guaranteed because it wasn’t included in the Bolivian National System of Protected Areas ( Mamani et al. 2010). Microlicia woodii is known by two collections from protected areas within RMTV; until additional collections are made we regard the conservation status of this species as Data Deficient (DD) following IUCN guidelines and criteria ( IUCN 2017). The region where M. woodii grows seems to be poorly sampled. The plants that grow on the plateaus between Santa Bárbara and Santiago de Chiquitos appear to be relatively free of threats ( Mamani et al. 2010); however, some authors have recommended a careful environmental monitoring of the region ( Huaylla et al. 2010, Segarra & Wood 2011, Pozo et al. 2013).

Etymology:— The specific epithet honors John R. I. Wood (1944–), collector of the two known specimens of Microlicia woodii . In promoting the study and conservation of the Bolivian flora (especially of the Andes and Cerrado), John has made many significant contributions to the knowledge of Bolivian floristics with special emphasis on the taxonomy and systematics of Acanthaceae , Convolvulaceae , and Lamiaceae .

Affinities:— Microlicia woodii is morphologically related to Microlicia sphagnicola Gleason (1931: 215) ( Fig. 3 , B) which is apparently endemic to Peru ( Gleason 1931), in the districts of Chontabanba (e.g., V. Martínez et al. 30376, NY), Huancabamba (e.g., V. Martínez et al. 33653, NY) in Oxapampa province, and in the Departamento de Junín (Killip & Smith 25680, NY). Both species have quadrangular branchlets, elliptic leaves (narrowly so in M. sphagnicola ) that are glandular-punctate on both surfaces and 3- to inconspicuously 5-nerved from the base, solitary flowers, calyx tube with intercalycine trichomes at the apex (externally at least), and dimorphic stamens with polysporangiate thecae. Microlicia woodii differs by its internodes that are beset with gland-tipped trichomes (vs. eglandular trichomes), leaves with short rectangular petioles 0.2–0.4 mm long (vs. sessile), wider blades 3.2–5 mm long (vs. ca 2 mm long), the margin flat (vs. revolute), flowers 5–6-merous (vs. 4–5-merous) with petals and stamen filaments magenta (vs. light pink). There are also notable differences in their elevational and habitat preferences: Microlicia sphagnicola was collected from 1,700 m (Killip & Smith 25680, NY) to 2,363 m (V. Martínez et al. 33653, NY) in montane forests and swamps covered with Sphagnum Linnaeus (1753: 1106) ; Microlicia woodii is known only from Cerrado regions with rocky outcrops at elevations spanning 920– 936 m. Other possible relatives are Microlicia benthamiana Triana ex Cogniaux (1883: 77) , M. colombiana Humberto Mend. & R.Romero in Mendoza-Cifuentes et al. (2019: 88) and M. guanayana Wurdack (1958: 95) . Microlicia woodii can be readily differentiated from these species by its nodes that are glandular-punctate and covered with gland-tipped trichomes (vs. glabrous in M. benthamiana ; glandular-punctate and covered with eglandular trichomes in M. colombiana and M. guanayana ) and leaf blades 3.2–5 mm wide (vs. 1.1–3 mm wide in the compared species). Additional comparative morphological features are given in Table 1.

Figures

FIGURE 1. Microlicia woodii. A. Habit. B. Detail of branchlet nodes and internodes. C. Leaf adaxial surface (left) and abaxial surface (right). D. Petal (adaxial surface). E. Flower (lateral view). F. Antepetalous stamen. G. Antesepalous stamen. G. Flowering hypanthium and calyx lobes. I. Capsule in cross-section.

FIGURE 2. Microlicia woodii. Photograph of holotype at K.

FIGURE 3. Field photographs. A. Paratype of Microlicia woodii (J.R.I. Wood 26016 & P. Pozo). B. Microlicia sphagnicola. Photograph A by J.R.I. Wood at Santiago de Chiquitos, Bolivia; B by Fabián A. Michelangeli in Peru.

FIGURE 4.Distribution of M.woodii andM.insignis in Bolivia.A.SouthAmerica, highlighting Bolivia.B. Bolivia,with the Departamento de Santa Cruz and the Parque Nacional Noel Kempff Mercado highlighted, and the occurrences of M. woodii and M. insignis.