Clusia heterocolorata L. Marinho & Bittrich, 2015

Marinho, Lucas Cardoso, Amorim, André Márcio & Bittrich, Volker, 2015, Clusia heterocolorata (Clusiaceae), a new species from the Brazilian Atlantic Forest, Phytotaxa 220 (1), pp. 83-88 : 84-87

Clusia heterocolorata L. Marinho & Bittrich , sp. nov. (sect. Phloianthera ) ( Figs. 1 , 2 , 3 )

Clusia heterocolorata L. Marinho & Bittrich is a dioecious tree with white to cream-colored latex. The staminate flowers have 5, cream colored petals; the androecium is dome-shaped, circular, with a prominent synandrium, the basal-lateral region has staminodes covered by resin and pollen. The pistillate flowers have 5, cream colored petals, with basal half pink; staminodes 4-seriate, resiniferous, surrounding the base of the ovary; 5 stigmas, smooth, obtusely triangular.

Type:— BRAZIL. Bahia: Mun. Almadina, Mirante da Serra do Corcovado, acesso pela roça do Sr. Francisco, 14º42’13”S, 39º36’08”W, 600–850 m, 20 November 2013, L. C. Marinho, L. C. Gomes, L. H. Daneu & D. S. B. Rocha 578 (fl. ♂) (holotype HUEFS!, isotypes CEPEC!, K!, NY!, P!, RB!, SPF!).

Trees up to 6 m tall, dioecious, with latex white to cream-colored; young branches cylindrical, with smooth surfaces, linear colleters present in the petiole axils. Petiole 6–8 mm long, cylindrical. Leaf blade coriaceous, discolorous, adaxial surface dark brown in sicco, obovate, (3–) 5.8–8.5 cm long and (2–) 4–5.5 cm wide, apex rounded, base rounded, rarely attenuate, margin revolute; midrib prominent on the adaxial surface and conspicuous up to the mid blade, secondary veins 13–15 pairs, prominent on abaxial and adaxial surfaces only in sicco, immersed in vivo, 3.5–5 mm distant from each other and forming an angle of 45º–60º with the midrib, basal veins inconspicuous; latex canals inconspicuous on adaxial surface, immersed, conspicuous only on abaxial surface in sicco, 0.1–0.4 mm distant from each other, parallel to the secondary veins, forming an angle of about 45º with the midrib. Inflorescence cymose, compact, 6-flowered (staminate plants) or 3-flowered (pistillate plants), bracts and bracteoles ca. 2.5 mm long, triangular, pedicels 0.5–15 mm long, cylindrical. Floral buds 10–11 mm long, orbicular. Epicalyx bracts 2, united at base, triangular. Sepals 8 (2+2, 2+2), green or light green, oblong to obtusely triangular; external sepals 8–10 mm long and 5–6 mm wide, internal sepals 6–7 mm long and 5–6 mm wide. Staminate flower with 5 petals, 10–11 mm long and 7.5–10 mm wide, obdeltiform to obovate, cream-colored, margin entire, not sinuous; androecium forming a dome-shaped, circular, prominent synandrium, 3–4 mm tall and 3–4 mm wide, composed of ca. 250 densely packed stamens, the upper surface covered by pollen during anthesis with low resin production, free portions of the filaments ca. 1 mm long, anther ca. 0.5 mm long, dehiscent by apical slits with inconspicuous apertures, base-lateral region of the dome-shaped androecium without anthers (staminodes) covered by a mixture of resin and pollen. Pistillate flower with 5 petals, 10–11 mm long and 9–10 mm wide, obdeltiform, cream-colored with basal half pink, margin entire and sinuous; 4 series of staminodes ca. 0.7 mm long surrounding the base of the ovary, secreting resins at their apices; staminodes orange, truncated at apex, without sterile anthers; styles ca. 1 mm long; stigmas 5, ca. 1.5 mm long, apical, yellowish, obtusely triangular, smooth; ovary 1.5–1.8 cm long, white, 5-locular, ovules 2–3 per locule. Fruit not seen.

Comparison: Clusia heterocolorata was assigned to the section Phloianthera (1860: 319) proposed by Planchon & Triana and confirmed by Gustafsson et al. (2007). This section comprises 11 species, mostly occurring in eastern Brazil, although some Amazonian and Andean species have been described. The androecium is commonly dome-shaped in this section, with numerous resiniferous stamens and staminodes. The male flowers of some species of the section, however, such as Clusia microstemon Planchon & Triana (1860: 331) and Clusia nitida Bittrich & F.N. Cabral (2013: 36) , have a flat, disc-shaped androecium with fertile stamens producing resins (i.e. as the male flowers lack staminodes).

Clusia heterocolorata is sympatric with Clusia melchiorii Gleason (1931: 403) , but they can be easily distinguished by the former having 5 petals (4 in C. melchiorii ), much more numerous stamens with very short filaments, and the presence of staminodes on the male flowers (the male flowers of C. melchiorii have up to 40 stamens with 3–5 mm long filaments, and lack staminodes) and floral resin (completely lacking in the nectariferous flowers of C. melchiorii ), besides, C. melchiorii belongs to C. sect. Anandrogyne. Clusia pilgeriana Mansf. (1924: 154) , is also similar to the new species and belongs to the same section ( Phloianthera ). It occurs on mountains covered by Atlantic Forest stands within the otherwise dry caatinga region (“ brejos de altitude ”) in Pernambuco and southern Paraiba States. Clusia pilgeriana can be distinguished by having less numerous sepals (4–5 instead of 8), the diameters of its flowers (35–40 mm vs. 23–25 mm in both flowers of C. heterocolorata ), its larger campanulate instead of radiate flowers (sepals 12–15 × 15–16 mm, petals 12–15 × 11–15 mm), and a 5–8-locular ovary (vs. 5-locular) with larger and sessile or subsessile stigmas (2–3.5 vs. ca. 1.5 mm long).

Etymology:— Greek heteros = different; Latin colorata = color. The specific epithet refers to the remarkably different colors of the corollas of the staminate and pistillate flowers.

Distribution, habitat, and conservation:— Clusia heterocolorata occurs in southern Bahia State, Brazil, in areas of dense montane rainforest (800 to 850 m alt.). The specimens were collected on a rocky massif (a type of inselberg) in the Corcovado Range. This mountain range is located at about 65 km from the coast in the municipality of Almadina and forms part of the Almadina River basin ( Coelho & Amorim, 2014).

The Clusia heterocolorata population examined contains approximately 20 staminate and pistillate plants that are randomly dispersed throughout an area of ca. 10 km ². As they grew on the top of the Corcovado massif, these trees are exposed to full sunlight and comprise part of the low canopy of this forested area. According to the criteria adopted by IUCN (2015), the species can be considered critically endangered as the population is composed of less than 50 individuals (D) and its extent of occurrence (B1) and area of occupancy (B2) are less than 100 km ².

Additional specimen examined (paratypes):— BRAZIL. Bahia: Mun. Almadina, Serra do Corcovado , entrando pela fazenda de Seu Francisco, 14º42’12.7”S, 39º36’8.6”W, 836 m, 23 November 2014 (fl. ♀), L. C. Marinho, L. H. Daneu, R. C. Asprino, R. F. Almeida & A. Francener 922 ( ALCB, CEPEC, HUEFS, RB, UEC, UFP) ; Mun. Almadina, Serra do Corcovado , entrando pela fazenda de Seu Francisco, 14º42’12.7”S, 39º36’8.6”W, 836 m, 23 November 2014 (fl. ♂), L. C. Marinho L. H. Daneu, R. C. Asprino, R. F. Almeida & A. Francener 923 ( CEPEC, HUEFS) .

Figures

FIGURE 1. Map showing the geographic distribution of Clusia heterocolorata (black circle).

FIGURE 2. Clusia heterocolorata. A—Stem with floral buds; B—Abaxial surface of the leaf; C—Detail of bracteoles and sepals of the staminate flowers; D—Staminate flowers; E—Detail of the androecium (L.C. Marinho 578); F—Detail of the bracteoles and sepals of the pistillate flower; G—Pistillate flower; H—Detail of the pistil and staminodes (L.C. Marinho 922); I—View of the Corcovado Range, Bahia State, Brazil (arrow indicates the collection site). Photos:A–E, I by L.C. Marinho; F–H by A. Francener.

FIGURE 3. Clusia heterocolorata. A—Stem with floral buds and staminate flowers; B—Floral bud; C—Detail of the bracteoles and sepals of the staminate flower in abaxial view; D—External sepal; E—Internal sepal; F—Petal of the staminate flower; G—Staminate flower; H—Detail of the androecium. I—Petal of pistillate flower; J—Pistillate flower; K—Detail of a pistil (A–H: L.C. Marinho 578, holotype; I–K: L.C. Marinho 922). Illustration by L.C. Marinho.