Martiodendron fluminense Lombardi. Brittonia, 2002

Falcão, Marcus José De Azevedo, Torke, Benjamin M., Garcia, Gabriel Santos, Silva, Guilherme Sousa Da & Mansano, Vidal De Freitas, 2023, A Taxonomic Revision of the Neotropical Genus Martiodendron (Fabaceae: Dialioideae), Phytotaxa 578 (1), pp. 11-56 : 33-36

Martiodendron fluminense Lombardi. Brittonia 54(4): 327 (2002).

Type:— Brazil: Rio de Janeiro: Rio das Ostras , Reserva Biológica Uni ã o, 22°31’S 41°56’W, Mata Atlântica, brejo ao lado do morro, trilha 7. Árvore, 24.4 m, DAP 92.95 cm, flores amarelas. 8-IV-1998, Oliveira, P.P. 890 BHCB44262 (Holotype: BHCB! Isotypes: NY!; RB!; SPF!). ( Figures 6–7 ) .

Trees (8–)18–25(–32) m tall, up to 50(–93) cm in diameter; with or without buttresses up to 1 m tall. Leaf rachis (3.4–) 7.5–12 cm long; petiole (0.7–)1.6–2.2(–4.6) cm long; petiolule 2–4(–5) mm long; leaflets (6–)7–9, the blades chartaceous to coriaceous, the terminal ones 5–8.4(–12) × 1.5–3.4(–5) cm, ca. (2–)2.5–3(–3.3) times longer than wide, ovate to elliptical, apex acute to cuspidate to acuminate, margins wavy, the adaxial surface often lustrous, slightly pubescent to glabrous abaxially, base obtuse to cuneate; axillary buds elliptic to oblong in outline, (1.3–)4.2–7 × 1–3 mm, apex acuminate to cuspidate. Inflorescences axillary or terminal, branching directly into cymes, without elongated primary or secondary axes, 4.2–10 × (4–)6–12.5(–16) cm, usually almost as long as wide. Flower buds 1.3–2.2 cm long, straight, apex straight or curved; sepals 1.3–2.2 × 0.15–0.4 cm; petals 1.3–2 × 0.4–0.9; stamens 5, commonly the abaxial one shorter than the others, rarely 4 stamens and 1 abaxial staminode, very rarely 4 stamens, anthers (0.8–) 1.3–1.8 cm × 1–2 mm, glabrous or rarely with sparse, inconspicuous indumentum; carpel 6–16 × 2–3 mm, fully pubescent; style 7–11 mm long. Fruits oblong to slightly asymmetrical, (7–)10–15 × 4–6.5 × 0.3–0.8 cm, 2–2.5 times longer than wide, red to vinaceous, with or without yellow stains along the sutures, wings 0.8–1.3 cm wide in the middle portion of the fruit, seminiferous nucleus occupying the central part of the fruit, ca. 2–2.7(–3.5) times wider than the widest of the two wings in the middle portion of the fruit, the abaxial vein generally closer to the abaxial border of the fruit at its midpoint.

Distribution, Habitat and Ecology: —The species is endemic to Brazil, being the most geographically restricted species occurring in the coastal forests in northern Rio de Janeiro and Espírito Santo ( Figure 15 ). Although, when observed on a larger scale, M. fluminense occurs in regions with lower average rainfall, such as the species M. mediterraneum ( Figure 16 ), they appear in different habitats, with M. fluminense occurring in coastal and humid forests of the Atlantic Forest, restricted to dense submontane, lowland or open rainforests, marshy areas and, less commonly, in seasonal semideciduous forests. In contrast, M. mediterraneum occurs in inland forests in the Cerrado or ecotone areas with the Caatinga and the Amazon, generally in savannas or seasonal semideciduous forests. The species usually occurs on clayey soils.

Etymology: —The species was named by Lombardi coming from the Latin fluminensis , name referring to the state of Rio de Janeiro, where the type was collected.

Phenology: —Blooms from January to May; fruits from March to October.

Uses: —So far, there is no mention of the use of the species. However, the wood of M. fluminense is like that of other species used ( Koeppen & Iltis, 1962) and may, therefore, have some local use for civil construction and furniture.

Conservation: —The species was cited as endangered and endemic of Rio de Janeiro state ( Martinelli et al., 2018). Here we first indicate its occurrence also in Espírito Santo state. It is considered frequent only in the municipality of Silva Jardim, Rio de Janeiro (H.C. Lima 4817), where is found in small fragmented forests, being rare in other regions. It is found in few protected areas such as Reserva Biológica Poço das Antas and Reserva biológica da Uni ã o. There are only 18 collected specimens, all in small pockets of humid forests, eight of them collected after 2000. An EOO of 10,981 km ² was estimated for M. fluminense , and based on A-D criteria of IUCN (2019), we suggest that the species should be considered vulnerable.

Vernacular Names: —No mention of vernacular names for this species was observed.

Taxonomic Comments: — Martiodendron fluminense are generally medium trees 18–25 meters tall, with only one known individual reaching 32 meters in height (P.R. Farag 17). It is usually taller than M. excelsum and M. mediterraneum , but shorter than M. elatum and M. parviflorum . It differs from all other species in the genus by its often smaller inflorescences reduced to cymes which can be axillary or terminal and by the fruits more elliptical and with the abaxial vein generally closer to the abaxial margin at its midpoint. It also differs from other species except M. elatum by having more stamens which differ from the stamens of M. excelsum and M. parviflorum by being glabrous. It typically has more leaflets than M. excelsum and M. parviflorum and fewer leaflets than M. elatum ; the terminal ones are generally narrower than in M. excelsum , wider than in M. elatum and shorter than in M. parviflorum . Its leaflets often have a wavy margin and lustrous surface, differing it from M. excelsum and M. parviflorum . It generally has shorter axillary buds than M. elatum and longer than M. parviflorum . Its floral buds are straighter than in M. parviflorum . It also differs from M. excelsum by its fully pubescent gynoecium. Its fruits are generally larger than in M. excelsum and in M. mediterraneum , slightly wider than in M. mediterraneum , with smaller length x width ratio than M. elatum and M. parviflorum and with the seminiferous nucleus wider in relation to the wings than in M. parviflorum ( Table 1 ).

The majority of characteristics proposed by Lombardi (2002) in differentiating M. fluminense and the species M. mediterraneum were here observed as variable in both taxa and not sufficient to distinguish them. These variable characteristics are the apex of the leaflet, the indumentum on the abaxial surface of the leaflet, and the size of the flower buds and petals. Despite this, both species are distinct from each other, not only because of their completely different distribution areas and environments of occurrence, but also because of some characteristics not punctuated by Lombardi as the frequency of the number of stamens: almost always four or, rarely, 4+1 staminode in M. mediterraneum and almost always five or, rarely, 4+1 staminode in M. fluminense and the branching pattern of the inflorescences: almost always terminal in M. mediterraneum , always with the primary and secondary axes elongated from which cymes develop, and axillary or terminal in M. fluminense , without the presence of elongated primary and secondary axes common to thyrsoids, with cymes developing directly from the branches, which can be isolated or form a synflorescence. Perhaps this shape, which generally leads to a more compact pattern in the inflorescences, led to Lombardi’s idea of “smaller inflorescences”. However, this does not distinguish the species, as both branching patterns can have similar overall sizes, with some cymes branching up to four levels and generating larger inflorescences in M. fluminense and some primary axes extending little and generating smaller inflorescences in M. mediterraneum .

Additional Specimens Examined (28 specimens): — BRAZIL: Espírito Santo: Conceiç ã o da Barra: próximo de Taquara. 20-VII-1954, Mattos , T. 48 ( RB); Itapemirim: Fazenda do Ouvidor, Usina paineiras, 20°55’32”S 41°3’1”W. 24-I-2008, Assis , A. M. 1315 ( MBML); 20°56’17”S 41°2’49”W. 15-III-2008, Assis , A. M. 1472 ( MBML); Cachoeira do Itapemirim , R. F.B. Norte, Acácio , G. 23 ( RB); Acácio, G. 38 ( RB); Acácio, G. 51 ( RB); Flona de Pacotuba, 20° 44’46”S 41°17’26”W, elev. 136 m. Árvore ca 25 m, Dias , H. M. 869 ( RB); Mimoso do Sul: Fazenda S ã o Bento, 21°12’31”S 41°20’16”W. 5-IV-2001, Pereira , F. B. 23/86 ( RB); Rio de Janeiro: Campos dos Goytacazes: morro do Itaoca. Árvore, 8 m, 23-II-2010, Mauad , L. P. 147 ( RB); Imbé. 15-X-1997, Moreno , M. R. 13 ( RB); Quissam ã, fazenda S ã o Miguel, 22°3’43”S 41°32’16” W. Árvore, 25 m × 93 cm DAP, 25-IV-2007, Ribeiro, R.D. 832 ( RB); Rio das Ostras: Reserva Biológica Uni ã o, 22°31’S 41°56’W. Árvore , 24.4 m × DAP 92.95 cm, 19-V-1998, Oliveira, P. P. 890A (RB); 15-V-2000, Oliveira , P. P. 890C (HUEFS); Silva Jardim: 22°31’9”S 42°16’29”W. Árvore, 20 m, 7-VIII-2016, Ribeiro , M. 1269 ( RB); Reserva Biológica de Poço das Antas: trilha do pau-preto. Árvore, 21 m, 10-VIII-1994, Luchiari , C. 495 ( RB); estrada Juturnaiba. Árvore, 25 m, 18-VI-1995, Luchiari , C. 662 ( RB); km3. Árvore, 20 m, 16-IV-1996, Luchiari, C. 721 (RB; UB; UEC); margens do rio S ã o Jo ã o, entre a BR101 e a ponte da linha férrea, 22°30-33’ S 42 °15-19’ W. Árvore , 8-X-1993, Correia , C.M.B. 364 ( RB); ilha próxima às margens do rio Aldeia Velha , limites com a Fazenda Arizona, 22°30-33’ S 42 °15-19’ W. Árvore , 18 m, 21-X-1993, Lima, H.C. 4817 ( RB; CEPEC); estrada da Barragem, 22°35’10”S 42°16’3”W. Árvore, 10 m, 26-V-2013, Neves, D.R.M. 1257 ( HUEFS; RB); ilha dos Barbados. Árvore , 24 m × 37 cm DAP, 14-III-1995, Lima, H.C. 5009 ( HUEFS; NY; RB; UB; US); 22°30-33’ S 42 °15-19’ W. Árvore , 32 m, 13-IV-1995, Farag, P.R. 17 ( INPA; RB); Árvore , 26 m × 118 cm CAP. 14-IV-1995, Farag, P.R. 20 ( ESA; MG; RB; UEC); unknown origin, possibly north of Rio de Janeiro , specimens cultivated in the Rio de Janeiro Botanical Garden, canteiro 32D, 22°57’57”S 43°13’37”W. Árvore, 25 m, 10-IV-2018, Falcão, M.J. 87 ( RB); 7-IV-1994, Lima, H.C. 4889 ( CEPEC; RB); 27-III-2017, Lima, H.C. 8502 ( RB; NY); VIII-2011, Marquete, R. 4287 ( RB); 30-X-2006, Ribeiro, R.D. 732 (RB).

Figures

FIGURE 6. Martiodendron fluminense Lombardi. A. Branch with leaf; B. Detail of the adaxial surface of the leaflet; C. Detail of the petiolule and leaflet base; D. Detail of the axillary bud enveloped by the stipules; E. Synflorescence; F. Flower bud; G. Flower; H. Stamen; I. Example of flower with abaxial stamen poorly developed in relation to the others, sepals and petals removed; J.Apex of anther with two pores still evident before tissue degeneration between them; K. Gynoecium; L. Detail of the stigma; M. Branch bearing fruits; N. Fruit; O. Seed.A–L: Falcão, M.J. 87; M–O: Marquete, R. 4287. Drawn by M. Falcão. Scale bar. A–B, E, N–O: 1 cm; C–D, F–I, K: 3 mm; J, L: 0.5 mm; M: 12 cm.

FIGURE 7 Martiodendron fluminense Lombardi. A. Canopy tree; B. Detail of the trunk; C. Trunk base with buttresses; D. Leaves and axillary inflorescences with young fruits; E. Inflorescence; F. Young fruits; G. Inflorescence; H. Tree top with mature fruits; I. Leaves and mature fruits; J. Detail of the mature fruit. Image authors: Marcus Falcão & João PauloAlves: Falcão, M. J. 87. Scale bar:A: 30 cm; B–C: 10 cm; D, I: 5 cm; E, G: 1 cm; F: 5 mm; H: 50 cm; J: 2 cm.

FIGURE 15. Martiodendron distribution map. Topographic map of part of the Neotropics containing all analyzed specimens of the genus separated by species and varieties. Note the occurrence of most species in areas with elevations below 200 meters, with the exception of M. mediterraneum, which generally occurs in regions of elevation 200–600 meters. Source: NASA with modifications.

FIGURE 16. Martiodendron distribution related to precipitation. Average annual precipitation map in mm of part of the Neotropical region containing all analyzed specimens of the genus separated by species and varieties in the case of M. elatum. Note the distribution of M. parviflorum and M. elatum var. elatum in wetter areas (orange color), M. elatum var. occidentale and M. excelsum generally in intermediate areas (red color), and M. mediterraneum in drier areas (green color) to intermediate areas. The preferential environments of M. fluminense in relation to humidity, despite occurring in a region with lower average precipitation (red to green color), are restricted to small areas of coastal rainforests with higher humidity. Source: WorldClim with modifications.