Caraipa glabra F.N. Cabral, 2017

Cabral, Fernanda Nunes, Bittrich, Volker & Amaral, Maria Do Carmo Estanislau Do, 2017, Two new endemic species of Caraipa (Calophyllaceae) from the Central Amazon Basin, Amazonas State, Brazil, Phytotaxa 311 (1), pp. 77-84 : 78-81

1. Caraipa glabra F.N. Cabral , sp. nov. ( Figs. 1 and 2 )

Type: — BRAZIL. Amazonas: Presidente Figueiredo, Cachoeira de Iracema , 01 o 59’23”S, 60 o 03’30”W, 109 m, 10 October 2012, F. N. Cabral et al. 581 (holotype INPA! (barcode 263969); isotypes MO! (barcode 100828134), UEC! (barcode 182460)) .

Diagnosis:— Caraipa glabra is a small tree distinguished from Caraipa ampla and C. longisepala by its completely glabrous leaves, pedicels and fruits. The leaf margins are slightly to strongly revolute, an uncommon character in Caraipa .

Description: — Small trees up to 5 m tall. Leaves distichous; lamina chartaceous and slightly to strongly revolute, elliptic, 4.5–9.3 × 1.7–3.7 cm, apex acute to obtuse, base acute to obtuse, adaxial and abaxial surface glabrous, abaxial surface without bulliform cells, dark dots, streaks or channels not visible; midrib sulcate adaxially, prominent abaxially; secondary veins 9 to 14 pairs, 5–9 mm apart; tertiary veins conspicuous only abaxially, parallel-reticulate; petioles 4–5 mm long, glabrous. Inflorescences racemose or flowers solitary, terminal or axillary, axis 1.1–1.2 cm long, with 1–2 flowers; pedicel 1.1–1.2 cm long; axis and pedicel glabrous; bracts and bracteoles caducous, bracteoles inserted in the lower half of the pedicel, near the pedicel base. Flowers not seen, only old flowers with shriveled stamens. Sepals tomentose with minute trichomes adaxially and glabrous abaxially, ciliate on margins, lobes 1.0–1.1 × 1.0– 1.5 mm, apex acute or rounded. Stamens numerous, filaments 4–5 mm long. Fruit ovoid, trigonous, 1.4–1.7 × 0.7–1.2 cm, beaklet ca. 2 mm long, surface longitudinally minutely rugulose, glabrous, valves not concave towards the base, exocarp separating from endocarp. Seeds not seen.

Etymology:— The epithet glabra refers to the absence of hairs on nearly all parts of the mature plant.

Phenology:— Flowering probably in March. Fruiting material collected in April, September and October.

Distribution and habitat:— Currently Caraipa glabra is considered endemic to the municipality of Presidente Figueiredo, Amazonas ( Brazil), occurring at two localities. One site at the margin of a small stream, locally known as Igarapé, in the Cachoeira de Iracema area, and the second near the BR-174 (Manaus-Caracaraí) road. On both localities, C. glabra occurs on white-sand vegetation, in lowlands up to 120 m altitude. In the area of Cachoeira de Iracema the site is located only a couple of meters away from the stream, and the area is flooded during the raining season (December to May) (see Fig. 4 ).

Conservation status:—Although Caraipa glabra has been only found in two sites in Brazil, it would be premature to infer a conservation status other than Data Deficient (DD; IUCN 2001). The species most likely has a broader distribution, but has not yet been collected elsewhere.

Taxonomic notes:— The most remarkable features that distinguish Caraipa glabra from the other Caraipa species is the complete lack of hairs on the leaf lamina, pedicel and fruit, and the slightly to strongly revolute margins of the leaf lamina. The only other species with glabrous pedicels are C. ampla Ducke (1922: 218) , C. longisepala Kubitzki (1987:160) , C. macrocarpa Cabral (2016: 253) , C. odorata Ducke (1932: 588) and C. richardiana Cambessèdes (1828: 414) (see Table 1). Overall, C. glabra is morphologically most similar to C. ampla and C. longisepala .

Additional specimens examined (paratypes):— BRAZIL. Amazonas : Presidente Figueiredo: Cachoeira de Iracema, 01°59’23”S, 60°03’30”W, 109 m, 11 September 2013, F. N. Cabral & G. Shimizu 965, 966, 967 and 976 ( INPA, UEC) ; Cachoeira de Iracema , 01°59’23”S, 60°03’30”W, 109 m, 21 April 2014, F. N. Cabral et al. 1150 ( INPA, UEC) ; BR-174, Estrada Manaus-Caracaraí, km 120, margem esquerda, ramal Fazenda Agroindustrial Chibata, 4 August 1993, C. A. Cid Ferreira & J. F. Ramos 11075 ( INPA) .

Figures

FIGURE 1. Caraipa glabra. A. Branch with fruits. B. Old flower, note the glabrous pedicel. C. Immature fruit. D. Mature fruit. E. Detail of abaxial leaf surface and revolute margin.

FIGURE 2. Caraipa glabra (A–B) and Caraipa iracemensis (C–F). A. Habit with immature fruit. B. Mature fruit, note the endocarp separating from the exocarp. C. Habitat and habit, note the caespitose habit. D. Flower buds and flowers. E. Immature fruits. F. Mature fruits.

FIGURE 4. Distribution map of C. glabra and C. iracemensis (by L. Melo).