An unusuAl new species of GuAtteriA ( AnnonAceAe ) from french GuiAnA And AdjAcent BrAzil ( AmApá )

of the Neotropical genera of Annonaceae, Guatteria ruiz & Pav. is by far the largest. currently about 400 names and about 290 species of Guatteria are recognised (Erkens 2007). the genus is easily recognised by the combination of axillary flowers/inflorescences with clearly visible articulation on the pedicel, an apocarpous fruit of stipitate monocarps, and an impressed primary vein on the upper side of the leaf. Due to the scattered distribution of the individuals in the distribution area and the low number of individuals per unit area (own and other researcher’s observation in the field), it is likely that the actual number may greatly exceed this. individuals of to date unknown species are easy to miss if they grow away from streets, paths, rivers, field stations, and settlements. Since the generic treatment of r.E. fries (1939, 1955, 1959) and some additional publications containing new species (fries 1941, 1948b, 1952, 1953), only accounts covering part of the genus, in regional floras and checklists, have appeared (e.g., Jansen-Jacobs 1976, Johnson & Murray 1990, Steyermark et al. 1995, Boggan et al. 1997, ribeiro et al. 1999, Hollowell et al. 2001, Maas & Maas-van de Kamer 2002, Erkens 2007). therefore an updated revision of this species-rich and ecologically diverse but morphologically homogeneous, and thus taxonomically challenging genus is needed. A recent revision can only be approached on a regional basis. the flora of the Guianas project, coordinated by the Utrecht branch of the National Herbarium of the Netherlands, offered the opportunity to revise the present diversity in the Guianas. Extensive collections have already been amassed at U. Meanwhile, taxonomic revisions have been

of the Neotropical genera of Annonaceae, Guatteria ruiz & Pav. is by far the largest.currently about 400 names and about 290 species of Guatteria are recognised (Erkens 2007).the genus is easily recognised by the combination of axillary flowers/inflorescences with clearly visible articulation on the pedicel, an apocarpous fruit of stipitate monocarps, and an impressed primary vein on the upper side of the leaf.Due to the scattered distribution of the individuals in the distribution area and the low number of individuals per unit area (own and other researcher's observation in the field), it is likely that the actual number may greatly exceed this.individuals of to date unknown species are easy to miss if they grow away from streets, paths, rivers, field stations, and settlements.Since the generic treatment of r.E.fries (1939,1955,1959) and some additional publications containing new species (fries 1941, 1948b, 1952, 1953), only accounts covering part of the genus, in regional floras and checklists, have appeared (e.g., Jansen-Jacobs 1976, Johnson & Murray 1990, Steyermark et al. 1995, Boggan et al. 1997, ribeiro et al. 1999, Hollowell et al. 2001, Maas & Maas-van de Kamer 2002, Erkens 2007).therefore an updated revision of this species-rich and ecologically diverse but morphologically homogeneous, and thus taxonomically challenging genus is needed.A recent revision can only be approached on a regional basis.the flora of the Guianas project, coordinated by the Utrecht branch of the National Herbarium of the Netherlands, offered the opportunity to revise the present diversity in the Guianas.Extensive collections have already been amassed at U. Meanwhile, taxonomic revisions have been undertaken and a number of new species have already been described (Erkens et al. 2006 (Mesoamerica), Erkens et al. 2008 (this Blumea issue p. 465-512, Amazonian Ecuador and Peru), Scharf et al. 2005, 2006a, b (Guianas)). in addition to the large number of specimens of Guatteria already collected in the Guianas over the last 250 years, and deposited in a number of herbaria -particularly that of the Utrecht branch of the National Herbarium of the Netherlands (U), recent discoveries of spectacular trees from this relatively well studied region exemplifies the fact that our knowledge of tropical plant diversity in general is still relatively incomplete.Even huge trees, suitable for timber, have escaped the attention of scientists and foresters.
in this article, a new species of Guatteria from french Guiana and Amapá in Brazil is described.the conspicuous tree trunk of this Guatteria first attracted the attention of the collectors, but all material that could serve as herbarium specimens was located out of reach of any pole-clipper since even the lowest limbs emerge from the trunk at great heights.climbing the tree was considered dangerous and thus not an option.All material of this species originating from french Guiana, now present in cAY and U, was harvested from the canopy of that exceptionally high (~40 m) tree with a gun.only a few individuals of this species are known at this collection site (pers.comm.MfP).However, an as yet nameless pile of mostly sterile collections from a second site in Amapá contained a number of vouchers that also refer to the same species.remarkable is both the width of the trunk at breast height and the buttresses, features which are also reported for the specimens from french Guiana.this second collection site is about 350 km away from the original collection site in french Guiana.Scharf & Maas,Map 1 Arbor elata G. paludosae r.E.fr.(1948a: 231) similis sed differt statura plerumque majore et anteridibus conspicuis (nec anteridibus nullis); praeterea laminis minoribus obovatis acumine breviore venis paucioribus, floribus sepalis et staminibus brevioribus, monocarpiis paucioribus sed longioribus, seminibus longioribus distincta.-typus: D. Sabatier & M.F.Prévost DS-MFP5047 (holo U; iso cAY), french Guiana, route cayenne to Saint Georges, km 122,5, close to Savane roche virginie, N 04°11' w 52°09 ', flowers, p.p. in alc., 27.7.2006.tree, up to 41 m tall, up to 79 cm dbh, with buttresses up to 2 m high and 90 cm at the base, limbs decurrent.Young twigs densely covered with appressed silvery hairs.Leaves: petioles c. 15 mm long, 2-3 mm diam., canaliculate, winged; blades obovate, 9 -21 cm long, 5.5 -8 cm wide, coriaceous, glabrous and dull, greyish to greenish brown, rough (not verrucose) above, dark brown (rarely tinged green) and dull in sicco, sparsely covered with appressed hairs, all over the surface rough (not verrucose) and conspicuously covered by circular structures below, base attenuate, margins revolute, apex acuminate (acumen 3-7 mm long); primary vein impressed and glabrous above, densely covered with straight, appressed, silvery hairs and slightly keeled (carinate) below, secondary veins distinct, 12-14(-16) on either side of primary vein, slightly impressed above, angles with primary vein 50-60°, forming a marginal vein, smallest distance between marginal vein and margin 2-3 mm.Flowers axillary and on older branches (ramiflory), 1 in a leaf axil; pedicels 11-14 mm (apical part: c. 12 mm) long, c. 2 mm diam., densely to rather densely covered with appressed silvery hairs, sepals broadly triangular to deltate, 5-6 by 5-6 mm, outer side densely covered with long appressed silvery hairs, apically (tips) reflexed, hook-like; petals yellowish green in vivo, petals subequal, elliptic or oblong-elliptic to obovate, 21-23 by 10-13 mm (immature), densely covered with short appressed silvery hairs, stamens pale orangebrown, 90-120, c. 1 mm long, connective shield umbonate, densely hairy; carpels black, 30-50.Monocarps c. 4, green in vivo (immature), greyish to blackish brown in sicco, ellipsoid, 20-22 mm long, c. 10 mm wide, apex acute and apiculate, glabrous, apex sparsely covered with some appressed hairs, stipes 5-8 mm long, c. 2 mm wide.
Ecology -Primary forest.Phenology -flowers in July; fruits in November.
Etymology -the new species name is derived from the conspicuous buttresses, which are unusual within the genus Guatteria.
Notes -1.Superficially, G. anteridifera is similar to G. brevicuspis r.E.fr.from sect.Mecocarpus.According w3tropicos (Missouri Botanical Garden 2008) G. brevicuspis is also known from marginal Amazonian Peru (Loreto, Madre de Dios), Bolivia (Beni, La Paz), and Ecuador (Napo, Sucumbios), next to the type locality in Brazil, Acre, rio Purus, avoiding the central part of Amazonia.the shortest linear distance between the type locality of G. brevicuspis and the site in french Guiana measures about 2500 km.Moreover, the conspicuous warts on both sides of the leaf in G. brevicuspis showed a clear difference to the new species.for both reasons a closer relationship could be excluded.
2. following the key of fries (1939) determination ends in sect.Leiophyllum, but neither G. scandens nor G. wachenheimii is the right name. the structure of the leaf  AcKNowLEDGEMENtS the work resulting in this publication was carried out in the context of the flora of the Guianas project, a critical treatment of the plant taxa occurring in the Guianas, and forms a contribution to flora Neotropica in close cooperation between the Universität Leipzig, Germany, Herbarium LZ and the Nationaal Herbarium Nederland, Utrecht University branch (U). the Latin diagnosis was translated by Lubbert Y.th.westra.Special thanks to Daniel Sabatier (cAY) who shot the specimens out of the crown of that exceptionally high tree and roy H.J. Erkens for constructive discussions and providing the distribution map. the research was only possible by loans and duplicates sent from AAU, B, BBS, BM, Br, BrG, c, cAY, f, fDG, K, Mo, NY, P, S, and US.All colleagues involved are gratefully acknowledged.

table 1 .
the new species Guatteria anteridifera compared with the probably closely related G. paludosa and the superficially similar G. brevicuspis.surface(notverrucosebutcoveredby tiny circular structures) is very similar to that of the species G. paludosa r.E.fr.(1948: 231)which is known in about 800 km distance from Guyana only and represents possibly the closest relative within the genus.Guatteria anteridifera is different from G. paludosa by being a generally larger tree with conspicuous buttresses; the blades are smaller and obovate and bear a shorter acumen and fewer secondary veins; the flowers have shorter sepals and shorter stamens; monocarps are less, but longer, the seeds longer (table1).Campbell et al. 14,256 (U), Campbell et al. 14,805 (U), Campbell et al. 14,844 (U), Campbell et al. 14,948 (U), Campbell et al. 15,128 (U), flowers, Campbell et al. 15,337 (U).