Microlicia ascendens Almeda & R.B.Pacifico, 2022

Pacifico, Ricardo & Almeda, Frank, 2022, New species of Marcetia and Microlicia (Melastomataceae) endemic to the campo rupestre of Chapada Diamantina, Bahia, Brazil, Phytotaxa 573 (1), pp. 39-69 : 49-52

Microlicia ascendens Almeda & R.B.Pacifico , sp. nov. ( Figs. 10–11 ).

Type:— BRAZIL. Bahia: Rio de Contas , Trilha do Pico do Itobira para o Vale do Mocotó , 13°22’49.9”S, 41°52’55.9”S, 1654 m, 16 June 2022, fl., fr., R. Pacifico 634, V.E. Bressan & E.A. Ramos (holotype: HUEM!, isotypes: CAS!, HUEFS!, RB!) .

Diagnosis:— Differs from Microlicia aurea Wurdack (1983: 124) by the glandular-punctate internodes covered with short gland-tipped trichomes 0.1–0.4 mm long (vs. only glandular-punctate), leaf blades obovate to oblanceolate (vs. elliptic-lanceolate) that are rounded at the apex (vs. bluntly acute), flowers with linear calyx lobes 2.3–2.7 mm long (vs. deltoid, ca. 1.4 mm long), and shorter petals 6.5–8 mm long (vs. 13.4–14 mm long).

Erect shrubs 1–2 m tall, much-branched. Upper cauline internodes 2–3 mm long, light green, sometimes flushed with red (when fresh) becoming pale green (when dry) and defoliated with age, quadrangular, not sulcate, with narrow wings up to 0.2 mm long, densely glandular-punctate and covered with short gland-tipped trichomes 0.1–0.4 mm long. Leaves decussate, ascending, concealing uppermost internodes (both when fresh and when dry), papyraceous, concolored, light green (when fresh) becoming pale green (when dry); petioles 0.7–1.5 mm long, light green, flattened; blades 6–9 × 1.7–4 mm, obovate to oblanceolate, apex rounded, base attenuate, margins entire, eciliate, both surfaces densely glandular-punctate, 1-nerved from the base, venation prominent on the abaxial surface and impressed on the adaxial surface, secondary venation not evident. Flowers 5-merous, sessile or on inconspicuous pedicels up to 0.5 mm long, apical or axillary, solitary or concentrated at the apex of the branches, ebracteolate. Hypanthia (at anthesis) 3.5–4 mm long, 2.8–3.6 mm wide at the torus, light green (when fresh) becoming pale brown (when dry), campanulate, equaling than the capsule in length at maturity, densely glandular-punctate. Calyx tubes 0.4–0.6 mm long. Calyx lobes 2.3–2.7 mm long (excluding apical trichome), 0.5–0.8 mm wide at the base, light green with a red apex (when fresh) becoming pale brown (when dry), patent at anthesis, linear, apex acute and mucronate, margins entire and glandularpunctate, externally glandular-punctate. Petals 6.5–8 × 3.5–5 mm, obovate, yellow, base attenuate, apex acute, both surfaces glabrous, margins entire and glabrous. Stamens 10, entirely yellow (excepting the white rostra), dimorphic, antesepalous anthers ± horizontal (at anthesis), subparallel and clustered, antepetalous anthers ± erect and clustered near the floral axis; antesepalous (larger) stamens with filaments 3.8–4.2 mm long, glabrous, thecae (excluding rostra) 2.3–2.8 × 0.6–0.8 mm, oblong, corrugated (polysporangiate), rostra 0.4–0.6 mm long, the ventrally inclined pores 0.2–0.3 mm wide, nearly circular, pedoconnectives 5.2–6 mm long, appendages 1.5–1.9 mm long, apex truncate; antepetalous (smaller) stamens with filaments 3.8–4.2 mm long, glabrous, thecae (excluding rostra) 2–2.4 × 0.5–0.7 mm, corrugated (polysporangiate), oblong, rostra 0.2–0.3 mm long, the ventrally inclined pores 0.1–0.2 mm wide, nearly circular, pedoconnectives 2.2–2.7 mm long, appendages 0.4–0.6 mm long, apex truncate. Ovary (at anthesis) 1.8–2 × 1.1–1.4 mm, superior, cylindrical, glabrous, 3-locular, not adnate to the hypanthium; style 6.5–7.5 mm long, yellow, glabrous, sigmoid, stigma punctiform. Fruit at maturity a globose loculicidal capsule 3–3.5 × 3–3.5 mm, pale brown, ovoid, 3-valvate, enveloping hypanthia, rupturing and flaking away with age, dehiscent from the apex to the base (basipetal), columellas deciduous. Seeds ca. 0.8 × 0.4 mm, brownish, oblong, testa foveolate, raphal zone nearly circular, ca. 25% the length of the seed.

Additional specimens examined:— BRAZIL. Bahia: Rio de Contas , trilha para o Pico do Itobira , 13°22’14.8”S, 41°52’59.9”W, 1802 m, 16 June 2022, fl., fr., R. Pacifico et al. 623 ( CAS!, HUEM!, HUEFS!, RB!) ; Pico do Itobira e arredores, 13°22’14.3”S 41°53’04.9”W, 1906 m, 16 June 2022, fl., fr., R. Pacifico et al. 627 ( CAS!, HUEM!, HUEFS!, RB!) ; Arapiranga, Gerais do Porco Gordo , Rio Galinha , 13°25’59”S, 41°45’09”W, 1174 m, 17 June 2022, fr., R. Pacifico et al. 641 ( CAS!, HUEM!, RB!) ; Pico do Itobira [“ Itoibira ”], 13°22’15”S, 41°53’05”W, [ca. 1870 m], 13 December 2006, fl., fr., A.K.A. Santos et al. 923 ( HUEFS!) .

Distribution, habitat and phenology:— Apparently endemic to the Chapada Diamantina in Rio de Contas ( Fig. 12 ; Appendix 2), where it grows in campo rupestre ( Fig. 4 ) exposed to full sun at elevations between 1174–1870 m. Collected flowering and fruiting in December, May and June.

Etymology:— The specific epithet refers to the distinctly ascendant leaves of this species.

Notes:— Besides Microlicia aurea (see diagnosis), another putative relative is M. obovatifolia R.B. Pacifico, Fidanza &Almeda (2017: 45) ( Fig. 5C ), which shares with M. ascendens the ascendant obovate leaves and flowers with dimorphic stamens. Microlicia ascendens differs from Microlicia obovatifolia by the glandular-punctate internodes covered with short gland-tipped trichomes 0.1–0.4 mm long (vs. only glandular-punctate), leaves with evident petioles 0.7–1.5 mm long (vs. subsessile), flowers with longer calyx lobes 2.3–2.7 mm long (vs. 2–2.2 mm long), yellow petals (vs. magenta) and androecium (vs. yellow and magenta), and longer anthers 2–2.8 mm long (vs. 1.2–1.5 mm long) with polysporangiate thecae (vs. tetrasporangiate). Among the compared species, only Microlicia aurea has been reported for Rio de Contas and might grow sympatrically with M. ascendens . Microlicia obovatifolia is endemic to Serra do Cipó in Minas Gerais state (see Appendix 1).

Suggested conservation status:— Critically Endangered (CR): B1ac(iv) (see Appendix 2).

Figures

FIGURE 4. Landscapes with campo rupestre vegetation in Chapada Diamantina, Bahia, Brazil. A. Serra da Batávia, Mucugê – type locality of Marcetia auricularia and Microlicia daneui. B. Serra do Barbado,Abaíra – type locality of Marcetia santosiae. C. Pico do Elefante,Abaíra – type locality of Microlicia prostrata (in the background, Serra do Barbado). D. Serra do Porco Gordo, Arapiranga (Rio de Contas) – type locality of Microlicia tetramera. E. Serra do Esbarrancado, Guiné (Mucugê) – type locality of Marcetia unguiculata. F. Serra do Gobira, Mucugê. Photos:A, by U. Marques; B–F, by R. Pacifico.

FIGURE 5. Selected photos of species compared to new taxa described in this study. A–B. Marcetia nummularia. A. Habit. B. Flower close up. C. Microlicia obovatifolia, flower close up. D. Microlicia cryptandra, flowering branch. E. Microlicia noblickii, flower close up. F. Microlicia parvula, flowering branch. G. Microlicia sulfurea, flowering branch. H. Microlicia juniperina, flowering branches. Photos: A–B, E, H, by R. Pacifico; C–D, F, by F. Almeda; G, by J.A. Siqueira Filho (HVASF herbarium).

FIGURE 10. Microlicia ascendens, photos of living plants. A. Habit. B. A flowering individual with Pico do Itobira in the background. C. Branch terminating in floral buds and flowers at anthesis (in lateral view). D. Branch with flower in frontal view. E. Fruiting branch. All photos by R.Pacifico. Vouchers:A, R. Pacifico et al. 623; B, R. Pacifico et al. 634; C–E, R. Pacifico et al. 627.

FIGURE 11. Microlicia ascendens, photos of dry specimens. A. Habit. B. Detail of branchlet. C. Leaf adaxial surface. D. Leaf abaxial surface. E. Floral bud. F. Petal adaxial surface. G. Antepetalous stamen. H. Antesepalous stamen. I. Gynoecium. J. Capsule enveloped by the hypanthium. K. Seed in lateral view. Scale bars: A, 2 cm; B–J, 2 mm; K, 0.2 mm. Vouchers: A, A.K.A. Santos et al. 923; B–J, R. Pacifico et al. 634.

FIGURE 12. A. Brazil with Bahia state highlighted. B. Bahia with the study area outlined (dashed line). C. Distributions of Microlicia ascendens, Microlicia daneui and Microlicia piatensis in the Chapada Diamantina, Bahia, Brazil.