Pouteria kossmanniae C.C. Vasconcelos & Terra-Araujo, 2020

Vasconcelos, Caroline C., Adrianzén, Marisabel U., Camargo, José Luís C. & Terra-Araujo, Mário H., 2020, Pouteria kossmanniae (Sapotaceae): a new species from Central Amazonia, Brazil, Phytotaxa 447 (4), pp. 265-275 : 271-272

Pouteria kossmanniae C.C. Vasconcelos & Terra-Araujo , sp. nov. ( Figs. 1–3 )

Type:— BRAZIL. Amazonas: Manaus, Universidade Federal do Amazonas - UFAM, campus ICHL, 3°5’23.11”S, 59°57’45.9”W, 18 July 2017 (fl), C. C. Vasconcelos et al. 165 (holotype: INPA, isotypes: HUAM, MG, RB).

Diagnosis:— Pouteria kossmanniae resembles P. macrophylla , P. manaosensis and P. rodriguesiana by the pentamerous flowers, papillate staminodes, and seed with a large hilum, covering almost the whole seed surface. Pouteria kossmanniae differs from these species by 12–14 secondary veins (vs. 12–33 pairs), 2.2–4.4 cm long petiole (vs. 0.9–2.8 cm long), 2.3–4.2 mm long pedicel (vs. 3–18 mm long), 1.3–2.2 mm long sepals (vs. 2.5–6.0 mm long), and 5.3–7.8 cm large fruit (vs. <5 cm or> 7.5 cm large fruit in diameter) ( Table 1).

Trees 17–22 m tall. Trunk 10–60 cm dbh, cylindrical, with small buttresses up to 1.5 m high (or absent on young trees). Bark ca. 1 mm thick, light brownish, densely fissured, not lenticellate; inner bark ca. 3 mm thick, reddish, and sapwood yellowish. Latex white, slightly sticky. Twigs cylindrical, smooth, grayish, glabrescent. Petiole 2.2–(3.6 ± 0.6)– 4.4cm long, not channeled, and twisted, appressed-puberulous with brownish trichomes.Leaves clustered at branch apices, spirally arranged, without stipules; blades 12.5–(16.2 ± 2.5)–21.1 × 4.0–(5.5 ± 0.8)– 6.6 cm, predominantly obovate (or elliptic in juveniles), chartaceous, discolor with green upper surface, glaucous lower surface, sparsely brownish appressed-puberulous on both surfaces, but most abundant on lower leaf surface (visible only with lens); base cuneate, sometimes slightly asymmetric; apex frequently acute, occasionally short or long acuminate; margin entire and slightly revolute; venation eucamptodromous, sometimes brochidodromous near apex; midrib slightly raised on the upper surface (carinate); secondaries parallel, straight and arcuate near the margin, 12–(13.6 ± 0.6)–14 pairs, flat with the blade on the upper surface and prominent on lower surface; intersecondaries absent; tertiary veins oblique, reticulate at higher-order veins.Apical bud 2.2–(2.8 ± 0.5)– 3.8 mm long, conical, densely brownish appressed-puberulous. Inflorescence borne in axillary fascicles, 2–(5.1 ± 1.7)–8-flowered. Flowers bisexual, 5-merous; pedicel 2.3–(3.5 ± 0.5)– 4.2 mm long, densely brownish appressed-puberulous. Calyx quincuncial, sepals suborbicular, 1.3– (1.8 ± 0.3)– 2.2 mm long, sparsely puberulous with brownish or translucent trichomes outside, glabrous inside, apex round, margin entire. Corolla cup-shaped, greenish, 1.9–(2.3 ± 0.2)– 2.6 mm long, sparsely strigose with yellowishtranslucent trichomes outside, glabrous inside; tube 0.8–(1.1 ± 0.3)– 1.5 mm long, lobes 0.7–(1.1 ± 0.2)– 1.5 mm long, ovate, apex round, margin papillate. Stamens fixed near the top of the corolla tube; filaments 0.5–(0.6 ± 0.1)– 0.8 mm long, glabrous; anthers 0.5–(0.8 ± 0.2)–1.0 mm long, sagittate, dorsifixed, extrorse and dehiscing longitudinally, glabrous; pollen grains 0.1–(0.5 ± 0.4)– 0.9 mm long, globose. Staminodes 1.3–(1.5 ± 0.1)– 1.7 mm long, lanceolate, papillate. Ovary 5-locular, 0.7–(1.0 ± 0.2)– 1.2 mm long, ovoid or globose, densely strigose with whitish trichomes; style 0.6–(1.2 ± 0.5)– 2.2 mm long, glabrous in the upper part; stigma minutely 5-lobed. Fruit an edible globose berry, ca. 5.3–7.8 cm in diameter, 79.2–(145.8 ± 42.7)– 207.8 g (in fresh material), densely appressed-puberulous with brownish trichomes when young, glabrescent and greenish when mature, rounded at base and apex; pulp farinaceous, yellowish-white, thick (ca. 2 cm). Seed 1–2, globose or plano-convex, 3.6–(4.3 ± 0.4)–5.2 × 3–(3.8 ± 0.4)–4.9 × 2.3–(3.6 ± 0.6)– 4.7 cm, 18.9–(36 ± 9.6)– 60.4 g (in fresh material); testa (seed coat) smooth, brown-reddish, thick, shiny, small, covering ca. 25% of the seed surface; hilum (seed scar) brown-grayish, slightly rough, covering almost the whole seed surface (> 75%); embryo basal, tiny, rudimentary axis, radicle included, cotyledons plano-convex, semi-fused, whitish, without endosperm. Seedling functional type Crypto-Hypogeal-Reserve ( CHR), unipolar with lateral axis to the petiolate cotyledons.

Additional specimens examined:— BRAZIL. Amazonas: Manaus, Universidade Federal do Amazonas, Setor Sul , entre os blocos B e G (próximo ICB), 3°6’2.70”S, 59°58’27.97”W, 69 m elev., 25 August 2018 (fl), C. C. Vasconcelos et al. 169 ( INPA) ; Universidade Federal do Amazonas, Setor Sul , entre os blocos B e G (próximo ICB), 3°6’2.7”S, 59°58’27.97”W, 69 m elev., 25 August 2018 (fl), C. C. Vasconcelos et al. 170 ( INPA) ; Universidade Federal do Amazonas, Campus ICHL, 50 m da agência do Banco do Brasil , 3°5’23.11”S, 59°57’45.9”W, 13 June 2018 (st), C. C. Vasconcelos et al. 167 ( INPA) ; Universidade Federal do Amazonas, Campus ICHL, passando a parada, 20 m à direita, 3°5’22.48”S, 59°57’46.75”W, 13 June 2018 (st), T. S. Silva et al. 10 ( INPA) ; Universidade Federal do Amazonas, Campus ICHL, próximo ao refeitório, 3°5’23.72”S, 59°57’54.76”W, 13 June 2018 (st), T. S. Silva et al. 11 ( INPA) ; Universidade Federal do Amazonas, Campus ICHL, 50 m da agência do Banco do Brasil , árvore s/n, 3°5’23.11”S, 59°57’45.9”W, 16 March 2016 (fr), C. C. Vasconcelos et al. 102 ( INPA) ; Mini-campus universitário da UA, Próximo ao bloco da prefeitura, 3°6’9.3”S, 59°58’26.53”W, 20 October 1998 (fr), L. Procópio et al. 71 ( HUAM) ; C. Universitário, próx. à Segurança, 03°06’2.24”S, 59°58’56.44”W, 14 November 1984 (fr), A. Webber et al. 578 ( HUAM) ; Mini-campus universitário da UA, Entre os Bl. D e, em frente a sala E-07,03°6’2.41” S, 59°58’28.55”W, 21 January 1999 (fr), M. R. Mesquita et al. 129 ( HUAM) ; Campus Universitário - U. A., Campo da Fac de Ed. Física , 3°5’59.44”S, 59°58’29.1”W, 5 November 1999 (fr), L. S. Machado et al. 108 ( HUAM) ; Campus universitário, próx. igarapé da alta tensão, 3°6’17.23”S, 59°58’41.99”W, 27 December 1985 (fr), A. Webber et al. 730 ( HUAM) ; Ponta Negra, Hotel Tropical, Árvore 442, 3°3’44.13”S, 60° 6’25.35”W, 21 July 1977 (fr), W. Rodrigues 10019 ( INPA) ; Rio Preto da Eva : ARIE-PDBFF Fazenda Dimona, reserva 2206, parcela 2206-2, quadrante 33, 2°19’53.95”S, 60°4’56.43”W, 9 September 1982 (fl), C. A. Mackenzie et al. 2206.865 ( INPA) .

Phenology:—Flowering from July to September and fruiting from October to March.

Distribution, Habitat, and Conservation status:— Pouteria kossmanniae is only known from the terra firme forest (non-flooded upland) in Manaus region, Amazonas, Brazil ( Fig. 3 ). It is presently known from only three sites; one being within a protected area ( ARIE-PDBFF) 80 km N of Manaus. The second site is a private property at Ponta Negra Beach, an urban area of Manaus with high anthropogenic influence. The last site corresponds to an urban forest fragment localized on the campus of the Universidade Federal do Amazonas ( UFAM, in Portuguese), where most specimens were collected. This forest fragment has an area of about 600 ha of primary and secondary Amazonian terra firme forest, in addition to cleared areas ( Borges & Guilherme 2000; Nery et al. 2004), and it became totally isolated about 20 years ago ( Tsuji-Nishikido & Menin 2011). This species has an EOO of 668 km 2 and an AOO of 16 km 2, representing three subpopulations (radius 5 km). Therefore, P. kossmanniae is assigned a preliminary status as Endangered ( EN): B 1a(iii)+2a(iii) according to IUCN Categories and Criteria.

Etymology:—The specific epithet honors Isolde Dorothea Kossmann Ferraz, our colleague at INPA, who has dedicated much of her time to study fruit, seed and seedling morphology of several plant families in Central Amazonia.

Near-infrared spectral signature ( NIRS):—Recent studies show the high predictive power of NIRS using dry leaves ( Durgante et al. 2013, Lang et al. 2015, 2017, Prata et al. 2018) and bark tissues ( Hadlich et al. 2018) to discriminate closely related plant species. NIRS data suggest that such similarity reflects phylogenetic relationships ( Kim et al. 2004), and therefore may permit the prediction of groups for samples for which DNA sequences are unavailable. Here, our results show that the discriminant models (cross-validations) built from spectral readings using dry leaves were able to predict overall species identity with a high accuracy. The rate of correct species discrimination was 89.6% accuracy with Leave-One-Out ( LOO) and 79.4% accuracy with Holdout ( HO). At the individual level, of 12 tested specimens of P. kossmanniae , a total of 83.3% were significantly discriminated from the other species.

Affinities and discussion:—We have not been able to demonstrate by molecular analysis the closest relatives to our new species. However, based on morphology, the new species is similar to Pouteria macrophylla , P. manaosensis , and P. rodriguesiana . Pouteria kossmanniae and P. macrophylla differ from P. manaosensis and P. rodriguesiana by the lower leaf surface being glaucous with sparse appressed indumentum visible only with a hand lens (vs. reddishbrown and golden-brown indumentum denser on lower leaf surface) and by the morphological features provided in Table 1.

Pouteria macrophylla and P. manaosensis belong to Clade I ( Faria et al. 2017), a clade also supported by two morphological characters, viz. papillate corolla margin and a pollen type called “A6” (still unknown in P. kossmanniae ). These species further share the following combination of morphological features: (i) oblique tertiaries (leaf venation) in seedlings and adult trees, (ii) fruit with farinaceous pulp, (iii) large seed scar that almost covers the entire seed surface, (iv) seeds with thick testa and semifused cotyledons, and (v) seedlings of type crypto-hypogeal-reserve (CHR), with several cataphylls development along of the epicotyl (unknown for P. rodriguesiana ) ( Pennington 1990, Vasconcelos 2017, Vasconcelos et al. unpubl. data). A seedling functional type refers to the following combination: emergence (cryptocotylar vs. phanerocotylar), position (epigeal vs. hypogeal) and function (e.g. photossytentic and reserve). The CHR type means that the cotyledons are hidden within the seed, which rest on the soil surface and are specialized for reserve storage ( sensu Garwood 2009 ).

Pouteria s.s., excluding Clade I, is distinguished on a combination of characters that includes a non-papillate corolla lobe margin, presence of staminodes, and seeds with plano-convex cotyledons having an included radicle and no endosperm ( Faria et al. 2017). This combination is also present in all members of Clade I, but the corolla margin is papillate, which supports the notion that P. kossmanniae is part of Clade I and not of Pouteria s.s. We therefore predict that the new species belongs to Clade I, which eventually could be resurrected as Lucuma . For the time being, however, the best solution is to instate it in Pouteria s.l.

Figures

FIGURE 1. Pouteria kossmanniae C.C. Vasconcelos & Terra-Araujo. A. Floriferous branch. B. Flower. C. Aestivation of corolla. D. Sepals showing the outer (left) and inner (right) surface. E. Open corolla with stamens and staminodes. F. Close-up of papillae. G. Gynoecium. H. Anther. I. Malpighiaceous trichomes on flowers and leaves. J. Fruit. K. Seed, showing the small seed coat (testa). (A–I from Vasconcelos et al. 165 [holotype], J, K from Vasconcelos et al. 102). Drawn by M.U. Adrianzén.

FIGURE 2. Pouteria kossmanniae C.C. Vasconcelos & Terra-Araujo. A. Tree in forest edge. B. Buttresses. C. Bark pattern. D. Bark slash. E. Upper (left) and lower (right) leaf surface showing venation and detail of midrib and indumentum. F. Fruiting branch. G. Closeup of reticulate higher venation (lower surface) seen against the light. H. Floral buds. I. Close-up of papillate corolla lobe margin and staminodes. J.Young fruit. K–M. Entire and cut-half of mature fruit showing the pulp and seed. N. Seeds. Photos A–D by J.G.L. Isacksson, E, G, I, J by C.C. Vasconcelos, H by M.U. Adrianzén, and F, K–N by I.D.K. Ferraz.

FIGURE 3. Known distribution of Pouteria kossmanniae and the three morphologically related species of Pouteria in Brazil (Sapotaceae, Chrysophylloideae).