Campomanesia costata M.Ibrahim & Landrum, 2013

De Oliveira, Marla Ibrahim U., Landrum, Leslie R., Oliveira, Reyjane Patrícia De & Funch, Ligia S., 2013, A new species of Campomanesia (Myrtaceae) from Bahia, Brazil, and its relationships with the C. xanthocarpa complex, Phytotaxa 149 (1), pp. 19-26 : 20-24

Campomanesia costata M.Ibrahim & Landrum , sp. nov. ( Figs. 1−3 )

Similar to C. xanthocarpa and C. aromatica differing by the predominantly oblong leaves, the strong elevated venation in the lower surface, as well as the convex and ovate calyx lobes.

Type: — BRAZIL. Bahia: Mun. Morro do Chapéu , estrada para Utinga, caminho para o povoado de Santa Úrsula, 1010 m elev., 11°39'30,1"S 41°07'58,5"W, 05 February 2010 (fr.), Ibrahim et al. 187 (holotype HUEFS, isotypes ASU, RB) .

Tree 4–7 m high; glabrescent, bark cracked; young twigs smooth, reddish brown, becoming rough, fissured, reddish brown or grey with age. Leaves mainly oblong, less often elliptic, sometimes narrowly elliptic, 5–13 × 2.7–5.2 cm, arching along their length and somewhat boat-shaped when fresh, once pressed and dried somewhat falcate, discolorous, lustrous, glabrous on both sides; apex acuminate to sharply acuminate, less often acute or obtuse, usually folded in dried specimens; base usually subcordate, obtuse or acute; margin entire or undulate, revolute; midvein and secondary (lateral) veins impressed-sulcate above, raised prominently below; pocket-like domatia present in the axils of the midvein with the secondary veins beneath; 7–11 pairs of secondary veins, leaving the midvein at an angle of ca. 30 degrees; venation brochidodromous, the marginal vein running within 1.5–3 mm of the margin; blades coriaceous, sometimes chartaceous when young, often rugose or costate, drying reddish brown to green; petiole 4–10 × 1.5–2 mm, channeled, puberulent. Flowers solitary in the axils of leaves, the plants known to us only in fruit; peduncles 10–25 × ca. 1 mm, glabrous; bracteoles not seen, probably deciduous at about anthesis; calyx lobes 5, convex, ovate or oblong, 3–5 × 2–2.5 mm, puberulent on both sides, usually the tears between lobes not entering the staminal ring; staminal ring pubescent; disk (including staminal ring) 4–8 mm across in fruit; stamens 130–150 (by scars), in 4–5 verticils; style ca. 4–6 mm long, filiform, glabrous; stigma peltate; locules 6-8, with one layer of glands; ovules ca. 5 (in the locule observed). Fruit globose, glandular, puberulent, yellow to orange when ripe, drying dark brown, 10–20 mm diameter, calyx-lobes persistent; seeds 2–5, 4–7 × 4–5 mm including the locular-wall.

Etymology: —The specific epithet alludes to the strongly elevated veins in the lower surface of the leaves, which give a costate aspect to them.

Vernacular name and uses: — Campomanesia costata is known as “gabiraba”, a common name for Campomanesia spp.

Relationships in Campomanesia : —This new species can be distinguished from others in the genus by the thicker and lustrous leaves in all stages of development, the strongly raised, thick veins in the lower surface of leaves, and the revolute margins ( Fig. 2C–D ). We believe that these characteristics are adaptations to the heat and dryness that are not found in Campomanesia xanthocarpa , a species morphologically similar to C. costata . Both are trees and have vegetative characters that overlap, like the form and dimension of leaves, the pocket-like domatia, the number of locules in the ovary, and the fruit color. On the other hand, C. costata has usually oblong leaves with subcordate base, a folded apex of the leaves in dried specimens, a petiole with more than 1.4 mm width, ovate or oblong calyx-lobes, and a puberulent hypanthium ( Fig. 2D–E ). Studies involving molecular data from ISSR markers and DNA sequences (ITS) of species from the “ Campomanesia xanthocarpa complex” (as defined by Landrum 1986) have shown that the population of C. costata differs from populations of C. xanthocarpa and that molecular sequences are dissimilar keeping the entities apart in phylogenetic analysis (Oliveira et al. in prep.). In addition, the new species has anatomical features, like presence of hypodermis and a continuous vascular bundle sheaths in the petiole and midvein of leaves, which are diagnostic in comparisons with C. xanthocarpa (Oliveira et al. in prep.). C. aromatica has not been included in these analyzes but a previous morpho-anatomical study conducted by Oliveira et al. (2011), which included C. aromatica and C. costata (then considered C. xanthocarpa ), showed they were distinct in the configuration of the vascular arc and nature of the vascular bundle sheaths in the petiole.

In fruiting specimens, leaves of Campomanesia aromatica could be confused with those of C. costata , since they change in texture and lose hairs, as observed by Landrum (1986) and Oliveira et al. (2012). Nevertheless, the new species has a different leaf morphology, in that the secondary veins leave the midvein in an angle less than 40°, the petiole is> 1.4 mm wide, the peduncle is> 1 mm wide, there are>100 stamens, and mature fruits are yellow instead of purple or black as they are in C. aromatica ( Fig. 2C–E ).

Phenology: —Fruits in February and March. According to people who live in the municipality of Morro do Chapéu, the flowering period is very short and occurs after the thunderstorms, in the months of October and November.

Geographic distribution and habitat: —Apparently endemic to Morro do Chapéu ( Fig. 3 ). Because of the mosaic of vegetation that occurs in the municipality, Campomanesia costata was reported in three types of shrubby vegetation: dry forests with sandy soils and rocky outcrops; rocky grasslands (campo rupestre); and savannas (cerrados). This is a different condition from C. xanthocarpa , which occurs in the Atlantic rain forest.

Conservation status: —According to França & Melo (2013), anthropogenic pressures are changing natural areas around the municipality of Morro do Chapéu, which has unique enclaves of caatinga and campo rupestre vegetations ( Zappi 2008). The authors noticed this during field work in the area. Campomanesia costata is a fruit tree and individuals were observed in the middle of grazing lands, with few other trees or shrubs. We believe that the individuals are preserved because of their edible fruits. Information about population status is not precise, but the known area of occupancy is around 415 km 2. Therefore, based on the IUCN Red List Criteria ( IUCN 2012) this species is considered Endangered (EN) under the criteria B2a.

Additional specimens examined (paratypes): — BRASIL. Bahia, Mun. Morro do Chapéu , 5 km ao sul da cidade, 1333m elev., 11°35’34”S, 41°11’54”W, 14 March 1996, fr., Woodgyer et al. 2391 (ALCB, BHCB, CEPEC, HRB, HUEFS) ; idem, Rio Ferro Doido um pouco embaixo à cachoeira, 879m elev., 11°37’15”S, 40°59’46”W, 03 March 1997, fr., Gasson et al. 5976 (ALCB, HRB, HUEFS, K) ; idem, estrada para Lagoa Nova , 876m elev., 11°44’58”S, 41°03’19”W, 06 March 1997, fr., Harley et al. 6088 (ALCB, CEPEC, HRB, HUEFS, K) .

Figures

FIGURE 1. A. Fruiting branch. B. Leaf base, lower surface. C. Leaf margin, lower surface. D. Leaf margin, upper surface. E–G. Variation of the leaf format. H. Fruit. I. Detail of the calyx-lobes.

FIGURE 2. Campomanesia costata. A. Habit. B. Detail of the cracked bark. C. Sulcate veins in the adaxial face of leaf. D. Fruiting branch. E. Calyx and stamen scars in the fruit. F. Cross section of the fruit in natura showing seeds covered by the glandular locular wall. G. Fruit in cross section showing six locules with a glandular wall; one seed developed.

FIGURE 3. Distribution map of Campomanesia costata in Brazil.