Leandra reptans R.Goldenb. & Reginato, 2013

Goldenberg, Renato & Reginato, Marcelo, 2013, A new reptant species of Leandra (Melastomataceae, Miconieae) from the Atlantic Forest, southeastern Brazil, Phytotaxa 94 (1), pp. 23-29 : 23-28

Leandra reptans R.Goldenb. & Reginato , sp. nov. ( FIGS 1 , 2 , 3 , 4 )

Type:— BRAZIL. Espírito Santo: Santa Teresa, Estação Biológica de Santa Lúcia , 28 November 2005, fl., L . Kollmann 8485 (holotype MBML, isotype UPCB) .

Reptant shrub, with a plagiotropic axis growing above the soil and producing erect, scandent shoots up to 5 m tall. Young stems terete, slightly swollen at the nodes, these with a faint interpetiolar line; surface sparse to moderately covered with minute (up to 0.1 mm diam.) stellate pedicellate trichomes, these denser and more persistent on the nodal region, caducous elsewhere, sometimes also with minute (0.1–0.2 mm long) unbranched, erect trichomes on the nodal region. Leaves isophyllous; petiole 1.5–2.5 cm long, inserted perpendicularly into the blade (in a peltate-like fashion), with the same stellate and unbranched trichomes as on the stems but a little denser; blade 5.5–12 × 2.3–5 cm, ovate, apex long acuminate, base cordate, margin entire, slightly hyaline (seen from below) and ciliate (0.2–0.5 mm long), membranaceous, usually dark purple on the abaxial surface, dull green on the adaxial; lateral veins basal, with two pairs plus an additional, faint, marginal pair, lateral and transversal veins prominent on the adaxial surface and plane on the abaxial surface; adaxial surface with dense, erect, rough unbranched trichomes 0.1–0.2 mm long, mixed with longer (0.4–0.6 mm long) and thicker unbranched trichomes that sometimes are curved in the apex, the indument on the nerves with denser big trichomes and sparser small ones, and also with minute glands ca. 0.1 mm long, sessile, reddish, abaxial surface with sparse to moderate erect, unbranched trichomes 0.1–0.2 mm long and sparse small glandular trichomes ca. 0.05 mm long, and also, on the nerves, minute (up to 0.1 mm diam.) stellate pedicellate trichomes. Thyrses 3–6 cm long, terminal, slightly pendant, lacking accessory branches, 1–4 pairs of paraclades, only the proximal or seldom the second and third pairs of paraclades branched and bearing more than one flower, in this case lax diads or triads, the axis densely covered with stellate and unbranched trichomes; bracts ca. 1 × 0.3 mm, linear-oblong, slightly naviculate, ciliate, apex rounded and topped with a trichome; bracteoles ca. 0.5 × 0.3 mm, triangular, with a trichome on the apex. Flowers sessile or on pedicels up to 0.4 mm long, 4–5-merous. Hypanthium 2.5–3 × 1–1.5 mm, terete, outside densely covered with stellate and unbranched trichomes, inner surface glabrous or with sparse, appresed unbranched trichomes; torus setulose, the setae larger at its vertices. Calyx tube 0.3–0.5 mm long, the lobes 0.9–1.5 mm long, rounded to triangular or ovate, always with a constriction at the base, deflexed at anthesis, both surfaces with stellate trichomes only; calyx teeth 1.5–2 mm long, narrowly triangular to short-subulate, thick, strongly deflexed (running parallel to the hypanthium), adaxial surface with stellate trichomes only, abaxial surface with stellate and unbranched trichomes. Petals 1.7–2 × 0.7–1 mm, white, triangular, apex acute, margin entire, glabrous. Stamens slightly dimorphic, white, filaments 1.2–1.4 mm long, anthers ca. 1.6–1.8 mm long, oblong to ovate with the apex slightly attenuate, connective not prolonged, in the antepetalous stamens with a pair of dorsobasal, blunt, gland-like appendages, the antesepalous stamens without these appendages. Ovary 3-locular, 2/3 inferior, the free portion projecting 0.3–0.5 mm, cylindrical, apex with stellate trichomes; style ca. 5.5 mm long, filiform, stigma punctiform. Berries ca. 5 x 4 mm, dark purple. Seeds 0.8–1 × 0.3–0.4 mm, elongateovate, unappendaged, the hilum covering 95% of the seed, tertiary sculpturing more conspicuous in the apical region, testa yellow, the cells periclinal walls flat or sligthly concave, the anticlinal walls jigsaw-like,.

Distribution and habitat: Leandra reptans is known only from the “Estação Biológica de Santa Lúcia ” (40° 36' 06" W, 19° 56' 10" S) in Santa Teresa, state of Espírito Santo, southeastern Brazil. This is Conservation Unit kept by the “Museu de Biologia Mello Leitão” and “Universidade Federal do Rio de Janeiro ” ( Mendes & Padovan 2000). The area is located between about 500 to 950 m above sea level, on a very rugged terrain, mostly covered with montane rain forest but also with shrubby vegetation on rocky outcrops. Leandra reptans grows on shaded hillsides under the forest canopy, and is quite common in the area. It was collected with flowers in November and December, and with fruits in February and March.

Etymology: The specific epithet refers to the reptant habit of the plants.

This species can be recognized by its reptant habit, leaves purple beneath and with a perpendicular, peltate-like insertion of the petiole into the strongly cordate blade base, calyx lobes with a basal constriction and antepetalous stamens with dorsal gland-like appendages. Unlike all species of Leandra know to us, this one has leaves with a particular venation appearance: the nerves are prominent on the adaxial surface, and plane on the abaxial surface. Inversely, other species of the genus (and even the whole tribe) have prominent nerves on the abaxial surface, and plane to impressed nerves on the adaxial surface.

The reptant habit is seldom found in Miconieae De Candolle (1828: 152) from eastern Brazil. Sometimes it can be associated with secondary epiphitism, like in Pleiochiton blepharodes (DC.) Reginato et al. (2010: 116) or Clidemia fluminensis Baumgratz & Souza (2010: 129 ; see Reginato et al. 2013), but in this case the plagiotropic axis is clearly terrestrial. Some species grow sideways, in a scandent fashion, and mostly on secondary vegetation, such as Leandra cardiophylla Cogniaux (1886: 99) , L. australis (Cham.) Cogniaux (1886: 104) , and L. nianga (DC.) Cogniaux (1886: 96) , but these do not have a distinctive plagiotropic axes and erect, scandent shoots like in L. reptans .

Leandra diffusa Cogniaux (1886: 146) is a scandent species that seems to be the closest to L. reptans , at least in overall morphological appearance. It occurs in the same area of L. reptans , but also in the states of Bahia, Rio de Janeiro, São Paulo and Paraná (pers. obs.). Leandra diffusa differs by the leaves with acute to rounded bases, petioles not perpendicularly attached to the blade, a single pair of lateral nerves (plus a faint additional marginal pair), trichomes on the inflorescence and hypanthium up to 1mm long, subulate bracteoles, calyx lobes much narrower, and calyx teeth slenderer.

Leandra reptans has been treated as “ Leandra sp3 ” in Goldenberg & Reginato (2006).

Paratypes: BRAZIL. Espírito Santo: Santa Teresa, Estação Biológica de Santa Lúcia, Mata Atlântica de Encosta , alt. 500–950m, 2 December 1996 (fl, fr), C. C . Chamas & R. R . Santos 457 ( MBML, RB, UPCB), Mata Atlântica de Encosta , alt. 500–950m, 20 October 1994 (bd), C. C . Chamas & R. R . Santos 265 ( UEC), Mata Atlântica de Encosta , alt. 500–950m, 20 October 1994 (bd), C. C . Chamas & R. R . Santos 277 ( MBML, RB, UPCB), Trilha Bonita , alt. 650m, 25 November 1998 (fl), L . Kollmann et al. 1087 ( MBML, UPCB), Trilha Bonita , 29 March 2000 (fr), P . Fiaschi et al. 697 ( SPF), Trilha do Sagui , 10 March 2001 (fr), V . Demuner et al. 880 ( MBML, RB, UPCB), Trilha do Indaiá-Açu , 8 February 2011 (fr), R . Goldenberg et al. 1532 ( MBML, UPCB, NY) .

Figures

FIGURE 1. A–F. Leandra reptans (all photographs by F. Michelangeli, from Goldenberg 1532). A. Reptant habit. B. Inflorescence. C. Detail of the young fruits. D. Leaf on adaxial view, showing the prominent nerves. E. Leaf on abaxial view, showing the plane nerves and perpendicular insertion of the petiole into the blade. F. Leaf on abaxial view.

FIGURE 2. A– F. Scanning electronic microscope images of Leandra reptans (from Demuner et al. 880). A. Leaf on abaxial view. B. Stellate pedicellate hair on leaf abaxial surface. C. Small glandular trichome on leaf abaxial surface. D. Mixed indument on the hypanthium external surface. E. Detail of the seed surface. F. Seed. Scale bars for A, D and F = 100 µm; B, C and E = 10 µm.

FIGURE 3. A–G. Leandra reptans (from Goldenberg 1532). A. Branch with leaves and inflorescence. B. Node. C. Inflorescence node with bracts. D. Leaf base on abaxial view. E. Leaf base on adaxial view. F. Nodal region of the branch, showing the interpetiolar line. G. Inflorescence detail.

FIGURE 4. A–J. Leandra reptans (from the holotype). A. Lateral view of the flower, with some parts removed. B. Lateral view of the hypanthium. C. Longitudinal section of the hypanthium. D. Petals. E. Calyx lobe, adaxial view. F. Longitudinal section of the ovary apex. G. From left to right: lateral view of an antesepalous stamen; lateral view of an antepetalous stamen; dorsal view of antepetalous stamen. H. Dorsal view of an antepetalous stamen, with the detail of the two dorsal lobes/glands. I. Detail of the stigma. J. Style.