Tovomita maxima Molino & J.Engel, 2022

Engel, Julien, Molino, Jean-François & Marinho, Lucas C., 2022, The maximum and the minimum: two new species of Tovomita Aubl. (Clusiaceae) from the Guiana Shield with an unusual number of stamens, Adansonia (3) 44 (16), pp. 165-174 : 166-170

Tovomita maxima Molino & J.Engel , sp. nov.

( Figs 1 ; 2 ; 3 ; 4 )

Tovomita maxima sp. nov. is similar to T. speciosa Ducke by the large and coriaceous leaves and large floral buds. The species can be distinguished by the floral bud and outer pair of sepals apiculate (vs rounded in T. speciosa ), the presence of bracteoles forming a calyptra around the floral bud or dichasium (vs absent in T. speciosa ); and higher number of stamens in T. maxima (74-many vs c. 50 stamens in T. speciosa ). Regarding staminate flowers, T. maxima sp. nov. is unique in the genus both by its exceptionally large (145), and unusually variable number of stamens (74-145).

TYPUS. — French Guiana. Montagne des Chevaux, parcelle SPP, tree SPP-624,4°41’N, 52°22’W, ♂ fl., 11.XI.2009, Sabatier & Fonty 5595 (holo-, CAY [ CAY112114 !]) .

ETYMOLOGY. — The specific epithet refers to the large size of this species, as well as its high number of stamens.

DISTRIBUTION. — T. maxima sp. nov. was collected in northern and southern French Guiana, in southern Guyana and in the Brazilian state of Amazonas in upper Solimões River.

HABITAT. — The new species was found in terra firme forest from sea level to around 1000 m a.s.l. Precipitations on the different localities vary from 2000 mm in southern French Guiana to 4000 mm for the most rainy localities in northern French Guiana, which makes T. maxima sp. nov. a fairly ubiquitous species in terms of water requirements.

PHENOLOGY. — Staminate flowers have been observed in October and November, staminate floral buds in August and December, (one) pistillate flower in April. Fruits were collected in January and March.

CONSERVATION STATUS. — The studied specimens come from twelve different localities, eight in French Guiana, three in southern Guyana and one in the Brazilian state of Amazonas in upper Solimões River. Based on these collections, the estimated extent of occurrence (EOO) is 228 815 km ² and the area of occupancy (AOO) is 44 km ². Among the 94 000 trees censused in the GUYADIV network ( Engel 2015), 65 individuals were identified as T. maxima sp. nov. The localities where this new species has been collected or identified in the field are not directly threatened by human activities. Tovomita maxima sp. nov. is thus classified as Least Concern (LC) according to IUCN Red List criteria ( IUCN 2012). However, this status must be considered with caution as it is a rare species whose survival and regeneration capacities could be affected by ongoing climate changes ( Phillips et al. 2008; Esquivel-Muelbert et al. 2018; Gomes et al. 2019).

AFFINITIES. — In Tovomita maxima sp. nov., large leaves resemble those of T. speciosa , a species known from the Brazilian states of Pará and Amapá ( Marinho 2020). However, the leaves of T. maxima sp. nov. have a longer petiole and the base of the lamina is attenuate vs cuneate in T. speciosa . Floral buds and outer pair of sepals are apiculate (vs rounded in T. speciosa ), the bracteoles form a calyptra while they are absent in T. speciosa ; and the stamens are much more numerous (74-many vs c. 50 in T. speciosa ). In French Guiana, T. gazelii Poncy & Offroy is the most similar species with its large, long-petioled leaves, its apiculate floral buds and its numerous stamens (90-100). However, this species is easily distinguished by its fruit covered with woody protrusions (a unique feature in Tovomita ), its chartaceous leaves (vs coriaceous in T. maxima sp. nov.) and its remarkable cone of prop roots that can reach 3 m high.

OTHER MATERIAL STUDIED. — French Guiana. Montagnes de la Trinité, zone sud, Bassin de la Mana , 400 m, 4°34’N, 53°21’W, fr., 15. I.1998, Granville & Crozier 13646 ( B, BRIT, CAY [ CAY004734 !, CAY004735 !], P [ P05061603 ]); Montagnes des Nouragues , bassin de l’Approuague, Arataye, 180 m, 4°3’N, 52°42’W, ♀ fl., 20.IV.1992, Larpin 1057 ( CAY [ CAY167622 !]); New road to Brazil (Route de l’Est), 7 kms S of the bridge over the Comté River , c. 52 km S of Cayenne, st., 12. I.1977, Mori 8898 ( P [ P04727131 ]); Régina , Savane-roche Virginie, parcelle SRV3, tree SRV3-103, 4°11’3”N, 52°8’50”W, st., 9.X.2007, Prévost et al. 5017 ( CAY!, MO); Piste de Saint-Elie , interfluve Sinnamary-Counamama, 5°20’N, 53°W, fr., 16. I.1991, Prévost & Sabatier 2995 ( CAY [ CAY167615 !], P [ P01155523 !]); Rivière Arataye , Saut Pararé – Bassin de l’Approuague, 4°2’N, 52°42’W, st., 17.X.1986, Sabatier 1449 ( CAY [ CAY167620 , CAY167621 !], P [ P01155524 !]); Petit Saut – Bassin du Sinnamary, 5°3’50”N, 53°3’17”W, st., 3.VII.1997, Sabatier et al. 4394 ( CAY [ CAY167616 !], P [ P01155525 !]); France-Brazil border, Borne Frontière N °1,parcelle BOU3, tree BOU3-586, 300 m, 2°12’43”N, 54°25’28”W, ♂ fl., 15.X.2006, Sabatier & Molino 5153 ( CAY [ CAY109336 !], MO); Montagne des Chevaux , carrière SCC., 28 m, 4°44’34”N, 52°26’12”W, ♂ fl., 23.XII.2008, Tostain et al. 2488 ( CAY [ CAY111776 !], NY, MO, P, U, US) .

Guyana. Upper Takutu-Upper Essequibo, Acarai Mts, ridge ascending to summit of unnamed peak, 6 km S of Sipu River , 700 m, 1°22’N, 58°56’W, ♂ fl. b., 26.VIII.1998, Clarke 7145 ( CAY [ CAY167617 !], US [ US00708843 ]); Acarai Mts, summit and adjacent slopes of Tinarmau Peak , 975 to 1000 m, 1°16’N, 58°35’W, fr., 6.III.1994, Henkel 4994 ( CAY [ CAY167618 , CAY167619 !], US [ US00587954 ]); Akarai Mountains: height of land between drainage of Rio Mapuera (Trombetas tributary) and Shodikar Creek (Essequibo tributary), 600-800m, st., 19.I.1938, Smith 3000 ( NY [ NY01416670 ]) .

Brazil. Estado de Amazonas – Upper Rio Solimões , Mun. São Paulo de Olivença, Estrada Bomfim, trail beyond road, 6 km S of town center, 3°30’S, 68°57’W, ♂ fl., 25.XI.1986, Daly 4430 ( NY [ NY01417001 ], US [ US01882507 ]) .

DESCRIPTION

Dioecious trees up to 30 m tall and 90 cm in diameter, prop roots up to 3 m high. Bark grey, exsudate yellow, abundant. All plant glabrous, including flower and fruit.

Leaves

Opposite; petioles 2.6-6.5 cm long, with an adaxial margined pit; leaf blades coriaceous, mostly broadly elliptic, 12.2-33 × 7.1-16.6 cm; apex slightly acuminate to rounded, rarely retuse; base attenuate; margin entire; midvein prominent abaxially and slightly raised adaxially; secondary veins in 9-15 pairs, 0.7-2.5 cm distant from each other, eucamptodromous, prominent abaxially and slightly raised adaxially; intersecondary veins usually absent or inconspicuous (sometimes visible in last third of the leaves); tertiary veins visible on both surfaces of young leaves but barely visible on mature leaves.

Inflorescences

Terminal. Male inflorescence a compact to ample compound dichasium, 3.5-12 cm long with up to 20 flowers; bracts not seen; bracteoles 7-11 × 3-9 mm, connate, forming a calyptra, often caducous; pedicels 9-34 × 1.5-3.5 mm. Female inflorescence reduced to a single flower.

Staminate flowers

Buds 8-18 × 6-15 mm, ovoid with a mucronate apex to spheroid with an apiculate apex, pale green. Flowers 1-2 cm diam.; sepals 4: two outer sepals 10-17 × 7-16 mm, fleshy, greenish, broadly ovate (to almost orbicular in buds), concave (cymbiform in buds), apex mucronate, and two inner sepals 6-15 × 5-11 mm, fleshy (although less than the inner sepals), greenish, broadly ovate, concave, apex mucronate; petals 4-7, 5-20 × 3-11 mm, linear to oblong to broadly ovate, apex rounded to acute; stamens 74-145, filaments 4-12 mm long, terete; anthers c. 1 mm long; pistillode 2-2.5 mm high × 1-2 mm large, stigmas 5.

Pistillate flowers

Pedicels c. 6 × 3 mm; receptacle c. 1.5 cm diam.; perianth not seen; staminodes 109, 5-8 mm long, terete; gynoecium 10 mm high × 5-7 mm large; ovary c. 3 × 6 mm, 5-locular, 1 ovule per locule; style c. 3 × 5 mm; stigmatic area c. 3 × 7 mm, stigmas 5, c. 2-3 mm wide, free from each other, sessile.

Fruit

A fleshy capsule, 5-6.8 × 3-4.6 cm, pericarp splitting septifragally into 5 valves, fragments of sepals, petals and staminodes persistent; epicarp smooth, greenish; mesocarp pinkish; endocarp orange-red; seeds 5, 2.8-3.4 × 1.3-1.7 cm, reniform, brown, covered with a bright orange-red aril.

Figures

FIG. 1. — Tovomita maxima Molino & J.Engel, sp. nov.: A, stem with male inflorescence; B, part of male inflorescence; C, staminate flower; D, detail of stamens; E, staminate floral bud longitudinal section (note the pistillode in the middle); F, pistillate flower (perianth missing); G, petals (from dissected bud); H, gynoecium (left), ovary transverse section (right); I, pistillate flower apical view; J, detail of staminodes; K; staminate floral bud (note calyptrate bracteoles); L, fruit medial section (left), fruit lateral view (right); A, B, Sabatier & Fonty 5595; C-E, K, Tostain et al. 2488; F, H-J, Larpin 1057; G, Sabatier & Molino 5153; L, Granville & Crozier 13646 (left), Henkel 4994 (right). Drawn by Laurence Ramon. Scale bars: A, B, I, 2 cm; C, 1 cm; D-I, K, 5 mm; J, 1 mm.

FIG. 2. — Tovomita maxima Molino & J.Engel, sp. nov.: A, male inflorescence; B, fruit; C, open fruit showing four seeds (one seed missing); D, seeds (two with the red aril removed, one in longitudinal section); A, Sabatier & Fonty 5595; B-D, no voucher. A-D, Photographs by Daniel Sabatier.

FIG. 3. — Tovomita maxima Molino & J.Engel, sp. nov.: A, gynoecium; B, pistillate flower (perianth missing); C, outer sepals; D, staminate floral buds (note calyptrate bracteoles); E; two inner sepals (top left) and seven petals; F, androecium; C, E, F, from dissected staminate floral bud; A, B, Larpin 1057; C, E, F, Clarke 7145; D, Tostain et al. 2488. Photographs by Julien Engel. Scale bars: A-E, 5 mm; F, 2 mm.

FIG. 4. — Distribution of Tovomita maxima Molino & J.Engel, sp. nov. (·) and Tovomita saulensis J.Engel & Molino, sp. nov. (*).