Dicorynia paraensis Benth. var. paraensis

Falcão, Marcus José De Azevedo, Torke, Benjamin Marland & Mansano, Vidal De Freitas, 2022, A Taxonomic Revision of the Amazonian Genus Dicorynia (Fabaceae: Dialioideae), Phytotaxa 554 (1), pp. 1-31 : 17-19

Dicorynia paraensis Benth. var. paraensis

= Dicorynia spruceana Benth. in Mart. Fl. Bras. 15(2): 81. (1870), nom. nud. TYPE: — BRAZIL. Amazonas: igapó from Barcelos upwards, XI-1851, Spruce, R. 1918/3501 (Holotype: K!; Isotypes: BR!; GH!; K!; NY!; P!; RB!; TCD!; W!).

Trees up to 26 m tall. Leaves 16–28 (–40) cm long, 5 (–7) leaflets, terminal leaflets generally broadly ovate to broadly elliptical to broadly oblong, less commonly elliptical to oblong, cordate to truncate to obtuse at base, the abaxial face glabrous, rarely sparsely pubescent, generally non-papillate, rarely papillate, (7.5–) 10.5–18 × 4–9 cm, the length 1.5– 2 (–2.3) times the width; petiolules (5–) 7–10 (–12) mm long; axillary buds commonly deciduous, laterally narrowly lanceolate to lanceolate, 1.5–3 (–4) × 0.5–2 (–3) mm, always close to the leaf attachment point, less than 0.5mm above it. Inflorescences ca. 22–32 × 4–14 cm long, sericeous, rarely tomentose, golden to brown, the lateral subthyrsoids long and almost always upward from their base, rarely with tertiary subthyrsoids branching before the emission of cymes; indumentum of the external face of the sepals and petals golden to brown. Fruits 4.2–7.5 × 2.5–3.7 × 0.4–0.5 cm. (Figs. 3E–G; 6D; 7A).

Distribution, Habitat, and Ecology: —The variety occurs in the Negro River basin in the southern extremes of Venezuela and in Amazonas, Brazil, from Cucui and Içanã downstream to the Anavilhanas. It appears to be most common in the upper drainage of the Negro River. Given the proximity of some of the collection localities to the Colombian border, the variety is to be expected in that country (Fig. 5). Virtually all specimens of the variety were collected from “igapó” forests. In parts of its distribution, it co-occurs with varieties macrophylla and uaupensis , but the former is strongly associated with terra firme forest. It appears to be the smallest variety, with the largest specimens reaching 20-26m in height.

Phenology: —Flowering occurs from November to December, fruiting from December to May.

Conservation: — D. paraensis var. paraensis has an EOO of 85,360 km and is known from a relatively small number of collections, most of which are old collections. Even though its EOO is high to consider the taxon threatened by IUCN’s criteria B, its rarity and lack of recent collections indicate that it can be considered Vulnerable, based on IUCN Red List criteria A, C, and D.

Nomenclatural Comments: —In the original description of the genus and generic type, D. paraensis, Bentham (1840) mentioned a material located by him in the Paris herbarium. However, no information about the specimen was offered. In his subsequent treatment for the genus in Flora Brasiliensis (1870), the only representative collection cited was Spruce 3501/1918 (BR; GH; K; NY; P; RB; TCD; W), a series of materials containing the name D. spruceana Benth. , a name never validly published and described solely as a synonym for D. paraensis in Bentham’s work (1870), being, in fact, a nomen nudum, as noted by Koeppen (1967). Such collection (from 1851) was made after the description of the genus ( Bentham 1840) so that it cannot be the original material. Koeppen (1967), identified a collection in P that was possibly the material used by Bentham to describe D. paraensis . It has no collector name or number and only the locality “ Pará ”. Koeppen indicates that this material was probably collected by L.C. Richard between 1781 and 1789 (such information, according to him, was obtained in correspondence with the then director of the Natural History Museum in Paris, Dr. Aubrevillei ) and considers this specimen as the type of D. paraensis , indicating the material (P 02142576) with the type label and mentioning in his work this unique specimen as a type, making it unnecessary to lectotypify it here, despite not using the word “ lectotype ” or “designated here” in his work (articles 7.11 and 9.4 of the Code: Turland et al. 2018).

Taxonomic Comments: —The typical variety of D. paraensis can be distinguished from D. paraensis var. uaupensis by the generally smaller number of leaflets, (although there is some overlap in this character), by the generally wider leaflets, longer petiolules, and by the shape and size of the axillary buds; from D. paraensis var. ingens by the generally smaller leaves, smaller number of leaflets, longer petiolules, and the shape of the axillary buds; and from D. paraensis var. macrophylla by the generally smaller leaves, smaller number of wider leaflets, shape and size of the axillary buds, and habitat preference (Table 1).

Additional Specimens Examined:— Brazil.— AMAZONAS: Anavilhanas, igapó, solo aluvial, margem do Rio Negro , 28-V-1988, Augusto, L . 675 ( INPA); Barcelos, igapós do Mariuá, entre a boca dos rios Itu e Aracá , 0°42’13”S 62°58’41”W, 9-III-2014, Flores, B. M . 37 ( INPA); Cucuí , 26-IV-1975, Nascimento, O. C . 216 ( IAN; RB); Santa Izabel, Rio Negro , 8-XII-1931, Ducke, A . s.n. RB24185 ( RB); 1-IV-1932 Ducke, A . 51 ( NY); São Gabriel da Cachoeira, alto Rio Negro, serra Uanari , margem esquerda, mata de igapó, 25-IX-1987, Lima, H. C . 3297 ( INPA; NY; RB); próximo a boca do Rio Uaupés, 0°3’22”N 67°13’48”W, 8-IV-2013, Cardoso, D. 3440 ( HUEFS; INPA); margem direita do Rio Negro, costa do Jupatí , 19-XII-1978, Damião, C . s.n. INPA80652 ( INPA; MG); igapó próximo à comunidade Tapajós , 5 km abaixo de São Gabriel, 0°10’44”S 67°0’41”W, 15-VII-2008, Zartman, C. E . 7581 ( INPA); mata de terra firme, terreno arenoso, 8-III-1975, Silva, N. T . 3783 ( IAN); margem do Rio Negro, vila Içana , 21-XII-1945, Fróes, R. L . 21539 ( IAN; NY; US); Rio Negro, próximo a São Felipe , 18-V-1975, Rosa , N. A . 368 ( IAN; MG; NY); alto Rio Negro, ilha de Nossa Senhora Aparecida , igapó, 13-XI-1987, Lima, H. C . 3197 ( INPA; NY; RB); Rio Negro infra ostium flum Curicuriary , 15-XI-1936, Ducke, A . s.n. RB35072 ( RB; US) ; Venezuela.— AMAZONAS: Rio Negro , 1°53’2,8”N 67°3’5.5”W, gallery forest on white sand. Tree, 20m. 16-II-2005. Redden, K. M . 3730 (NY; US).