Two new species of Guatteria ( Annonaceae ) from the Atlantic Forest of Brazil

Guatteria emarginata and G. stenocarpa, two new species from the Atlantic Forest in Espirito Santo and Bahia, Brazil, are presented here. Guatteria emarginata is characterized by narrowly obovate, verruculose leaves, densely covered with cinereous hairs on the lower side and an emarginate apex. Guatteria stenocarpa is remarkable among the Atlantic Forest species of the genus for its narrowly ellipsoid to cylindric monocarps of 22-25 mm long.


INTRODUCTION
Guatteria Ruiz & Pav. is the largest genus of the family Annonaceae, comprising c. 300 species (Erkens et al. 2008) distributed from SE Mexico to Bolivia and S Brazil (Barringer 1984), with centres of diversity in the Amazon basin and Guianas.The genus is characterized by an impressed primary vein on the upper side of the leaves, axillary flowers, pedicel with a distinct suprabasal articulation, imbricate petals and an apocarpous fruit with numerous 1-seeded indehiscent monocarps.
Guatteria is taxonomically problematic because of the uniformity of the flower and fruit characters (Van Heusden 1992) together with the variability of the vegetative characters that can overlap among species.Furthermore, the immature flowers (open bud) look very different from the mature ones, leading to frequent confusion in delimitation of species.Because of the problematic interpretation of these characters, the number of species could have been overestimated (Lobão & Mello-Silva 2007).Nevertheless, the two species described here are unique in their characteristics, and they both inhabit the Atlantic Forest of Brazil.This forest originally covered 1 400 000 km 2 of the Brazilian coastal mountains (Rizzini 1997) and is today reduced to less than 100 000 km 2 (Galindo-Leal & Gusmão Câmara 2003).For its high amount of biodiversity and endemism, this biome has been classified as one of the 25 world hotspots for conservation (Myers et al. 2000).The discovering of these two new species strengthens both the need for more systematic studies in Guatteria and the importance of the Atlantic Forest for conservational purposes.Lobão, Maas & Mello-Silva, sp. nov.-Fig.1a Tree c. 17 m tall; young twig sparsely covered with appressed greyish hairs.Leaves: petiole canaliculate, 3 -4 mm long, blackish, sparsely to densely covered with appressed greyish hairs; lamina slightly coriaceous, verruculose, narrowly obovate, 5-9.5 by 1.5-3 cm, base attenuate, basal margins rolled inwards, apex emarginate, brown when dry, glabrous above, densely covered with appressed hairs below, primary vein flat on upper side, glabrous, secondary veins distinct, 13-16 pairs, raised on both sides, angles with primary vein 70-80°, tertiary veins reticulate, raised on both sides.Flowers solitary, axillary; bracts 2, soon falling off; pedicels 15-30 mm long, blackish, sparsely to densely covered with appressed, greyish hairs, articulation at 1/4 to 1/3 from the base; flower buds broadly ovoid; sepals green in vivo, broadly triangular, c. 4 by 3 mm, densely covered with curly hairs on lower side, reflexed; petals pale red in vivo, broadly ovate, the outer whorl slightly smaller than the inner, 5-9 by 6-7 mm, densely covered with curly hairs on both sides; stamens c. 1.5 mm long, connective shield papillate; carpels c. 2 mm long, ovary densely covered with appressed, golden brown hairs, stigma papillate.Fruit not seen.Distribution -Brazil, Espírito Santo; known only from the type locality.Habitat & Ecology -Mountain Atlantic Forest; altitude 600-850 m.
Etymology -The specific epithet refers to the narrowly ellipsoid to cylindric monocarps, an uncommon feature for Guatteria and unique in Guatteria from south-eastern Brazil.
Notes -Guatteria stenocarpa is characterized by slightly coriaceous leaves and narrowly ellipsoid to cylindric monocarps of 22-25 mm long.Among the SE Brazilian species of Guatteria, G. stenocarpa is vegetatively similar to G. oligocarpa and G. pogonopus because of the glabrous and slightly coriaceous to chartaceous leaves, which are also of the same length.However, G. oligocarpa and G. pogonopus have ellipsoid monocarps which are less than 20 mm long.

CONSERVATION STATUS
The two species occur in the Atlantic Forest of eastern Brazil, a threatened ecosystem.The species are rare and only G. emarginata occurs in a legally protected conservation area.The best category of the IUCN Red List (IUCN 2001) for G. emarginata would be DD (data deficient) and that for G. stenocarpa EN (endangered), fitting them into IUCNs B.1.a.c.criteria.