Doliocarpus stehmannii Monzoli, Aymard & Fraga, 2025

Monzoli, João Victor Longhi, Aymard, Gerardo, Araújo, Michelly De Deus Felipe, Fraga, Claudio Nicoletti De & Sampaio, Daniela, 2025, Doliocarpus stehmannii (Doliocarpoideae, Dilleniaceae): a new species of water vine from Brazil, Phytotaxa 705 (2), pp. 193-202 : 194-199

Doliocarpus stehmannii Monzoli, Aymard & Fraga , sp. nov. ( Figs. 1 , 2 )

Type:— BRAZIL. Minas Gerais: São Gonçalo do Rio Abaixo, Estação Ambiental de Peti, Bom Será , depois do Rio Santa Bárbara , 19º53’11.6”S, 43º22’27.1”W, 674 m, 20 June 2023 (fr), J. V. L. Monzoli 643 (holotype: SJRP! [bc35249]; isotypes to be distributed to: BHCB, COL, RB, W) .

Doliocarpus stehmannii resembles D. hispidus Standl. & L.O.Williams in Williams (1961: 350) by the leaf indument and venation, but differs by the lack of brachyblasts (vs. brachyblasts present in D. hispidus ), 8−11 pairs of secondary veins (vs. 15−20), adaxial surface of the sepals glabrous (vs. densely hispidulous-pubescent or sericeous) and glabrous fruits (vs. densely pubescent).

Lianas twining, 2.5–18 m long. Stems 1–3 cm diam., cylindrical; cross section with a single cylindrical xylem, surrounded by a continuous layer of phloem and, with axial vascular elements in radial segments, orangish to reddish; bark peeling off in chartaceous plates, greyish to reddish. Branches and branchlets cylindrical or angular, lanate or hirsute-lanate, and green when young, cylindrical, lanuginose, and brownish when mature; bark peeling off in greyish to brownish long plates. Leaves petiolate; petioles 0.5−1.3 × 0.1−0.4 cm, canaliculate due to folding of two lateral carinas, margin often lacerate, adaxial surface glabrous or lanate, abaxial surface sparsely lanate, including carinas, green; blades 5−18.7 × 3.2−7.9 cm, oblanceolate, obovate, rhombic-oblanceolate or elliptic, papyraceous to chartaceous, base attenuate, cuneate or acute, slightly decurrent, forming carinas along the petiole, apex acuminate, acumen 0.3−1 cm long, margin plane, dentate or serrate mostly in the upper half of the blade, adaxial surface sparsely lanate, midrib densely lanate, abaxial surface sparsely lanate, lanate along veins, velutinous, trichomes white to ochre; venation craspedodromous, veins plane or sometimes slightly impressed adaxially, prominent abaxially, secondary veins in 8−11 pairs, tertiary veins straight, opposite percurrent. Inflorescences ramiflorous or axillary, botryoid, rachis 2−3 mm long, tomentose-lanulose, 9−15-flowered; bracts 1.2−1.3 × ca. 1 mm, obovate, cucullate, base truncate, apex rounded, margin entire, adaxial surface glabrous, abaxial surface sericeous-tomentose, trichomes white to yellowish. Flowers pedicellate; bracteoles 1.25−1.85 × 1− 0.95 mm, obovate, cucullate, base truncate, apex rounded, margin entire, adaxial surface glabrous, abaxial surface sparsely sericeous-tomentose, trichomes white to yellowish; pedicel 2−5.3 × ca. 0.3 mm, lanate; sepals 5, 2.6−3.2 × 1.7−2.1 mm when blooming, 3.7−4.1 × 2.5−3.5 mm when fruiting, obovate, cucullate, base truncate, apex rounded, margin entire, adaxial surface glabrous, abaxial surface glabrous or very sparsely lanulose, color when blooming unknown, green to reddish when fruiting, trichomes white to yellowish; petals ca. 5.1 × 2.2 mm, spatulate, base truncate, apex obcordate, margin entire, both surface glabrous, cream; stamens 12−18, filament 3.5−4.6 mm long, glabrous, anther 0.16−0.22 × 0.32−0.4 mm, oblong-elliptic, glabrous; ovary 0.9−1.9 × 1.2−1.75 mm, orbicular, glabrous, style ca. 0.96 mm long, glabrous, with stigma ca. 0.48 mm wide, orbicular, glabrous. Fruits 5.9−8.1 × 7.2−9.5 mm, globose, glabrous, green at the base, vinaceous or burgundy towards the apex, persistent sepals reflexed or patent, not appressed to the fruit. Seeds ca. 3.2 × 3 mm, subreniform, glabrous, lustrous, black, totally covered by a white to cream, translucent aril.

Distribution and habitat:— Doliocarpus stehmannii is endemic to the upper Doce River basin, in the mid-eastern of the state of Minas Gerais, southern Brazil, in a geological area known as “Iron Quadrangle”. This name refers to the high mineral content found in the area, especially iron. The new species has been collected only at the municipalities of São Gonçalo do Rio Abaixo (in the Peti Ambiental Station) and Itabira in forest fragments inside private properties ( Fig.3 ). The species inhabit semideciduous seasonal forest vegetation, near rock outcrops, at elevations of 650−900 m ( Fig. 4 A-B). Neighboring anthropized areas includes Pinus sp. plantation ( Fig. 4 C-D) and mining ( Fig. 4B ).

Informal conservation status:— Doliocarpus stehmannii has been recorded so far by only nine individuals from two localities, resulting in an estimated extent of occurrence (EOO) of 26.9 km 2 and an area of occupancy (AOO) of 16 km 2. These figures fall within the limits for Critically Endangered (CR) status under the criterion B1 (EOO less than 100 km 2) and Endangered (EN) under the criterion B2 (AOO more than 10 km 2 and less than 500 km 2).

Due to the high content of iron and manganese in the Iron Quadrangle, both localities are under great pressure of mining. In Itabira city, the species was recorded inside Pinus sp. plantation ( Fig. 4 C-D), in an area influenced to the south by Itabira mining complex, exploited by Vale Company. In São Gonçalo do Rio Abaixo city, the species is found in the Peti Ambiental Station, an area implemented in 1983 by Companhia Energética de Minas Gerais ( IEF 2014) with 1,374 ha, being 605 ha of vegetation and 677 ha of water reservoir, and nowadays under the responsibility of São Gonçalo do Rio Abaixo City Hall. This station is surrounded to the south by the Peti dam (hydroelectric plant), upstream by monocultures of Eucalyptus spp. , agricultural areas, and pastures and to the north by Brucutu mining complex, exploited by Vale Company ( Fig. 4B ). These activities can lead to a reduction in the number of locations to one, and to a decline in the area of occupancy, extent of occurrence, and quality of habitat of the new species. Based on this context, we decided to apply the criterion B1 and suggest the conservation status of D. stehmannii as Critically Endangered [CR: B1ab(i, ii, iii)].

Etymology:— The epithet honors Dr. João Renato Stehmann, renowned botanist at the Universidade Federal de Minas Gerais, who collected this species for the first time and has contributed to the knowledge of Dilleniaceae , specifically the genus Davilla , when supervised the third author in his PhD.

Phenology:— Collected with flowers in March, and with young and mature fruits in June, August, and September.

Taxonomic notes:— Because of the hirsute indument along petioles and blades, and the craspedodromous leaves, this new species resembles Doliocarpus hispidus but differs by the features cited in the diagnosis. We found four specimens housed in herbaria collections, three of which were left undetermined in Doliocarpus , and one which was identified as D. dentatus . This latter species is widely distributed, very frequent in Brazil, and can be found in semideciduous seasonal forests of Minas Gerais state, although it has leaves with tomentose-sericeous abaxial surface, fasciculate and sericeous inflorescences, and red fruits, while D. stehmannii has leaves with lanate abaxial surface, botryoid and tomentose-lanulose inflorescences, and vinaceous fruits.

Vinaceous fruits are rare in Doliocarpus . Besides D. stehmannii , it occurs only in D. glomeratus Eichler (1863: 77) along the Atlantic Forest, but the latter species has domatia in the axils of secondary veins on abaxial surface of the leaves and occurs in ombrophilous forests at southern and southeastern Brazil, while the former lacks domatia and occurs in semideciduous seasonal forests of the Iron Quadrangle area in the state of Minas Gerais.

When using the key to species of Doliocarpus for the Brazilian Atlantic Forest ( Monzoli et al. 2022), D. stehmannii would key out in the species group with glabrous fruits, dentate leaf margins, botryoid inflorescences, and leaves without domatia, together with D. serrulatus Monzoli & Fraga in Monzoli et al. (2022: 953) and D. heterophyllus Monzoli & D.Sampaio in Monzoli et al. (2022: 956), but none of these present leaves adaxially hairy and vinaceous fruits. An updated key is presented here to accommodate the new species (below).

Additional specimens examined (paratypes):— BRAZIL. Minas Gerais: Itabira , 19º35’43”S, 43º16’55”W, 987 m, 29 August 2014 (fr), F. D. Gontijo et al. 924 ( BHCB! [bc] BHCB185910 ) ; ibidem, 19º35’18.6”S, 43º16’23.1”W, 902 m, 21 June 2023 (fr), J. V. L. Monzoli 651 ( SJRP! [bc] SJRP35248 ). São Gonçalo do Rio Abaixo, Estação de Peti — CEMIG, 09 March1988 (fl), J. R. Stehmann et al. 886 ( MBM! [bc] MBM145722 ) ; ibidem, 20 June 2002 (fr), J. A. Lombardi & A. Salino 4927 ( BHCB! [bc] BHCB71705 ; ibidem, estrada para o Bom Será, após cruzar o Rio Santa Bárbara , 26 September 2002 (fr), J. R. Stehmann & G. S. França 3380 ( BHCB! [bc] BHCB75754 ) ; ibidem, 19º53’14.2”S, 43º22’19.8”W, 674 m, 20 June 2023 (fr), J. V. L. Monzoli 642 ( SJRP! [bc] SJRP35247 ) ; ibidem, subida após o Bom Será , 686 m, 20 June 2023 (fr), J. V. L. Monzoli 644 ( SJRP! [bc] SJRP35244 ) ; ibidem, 697 m, 20 June 2023 (fr), J. V. L. Monzoli 645 ( SJRP! [bc] SJRP35245 ) ; ibidem, estrada para o mirante, 19º53’28.5”S, 43º22’04.4”W, 779 m, 20 June 2023 (fr), J. V. L. Monzoli 646 ( SJRP! [bc] SJRP35246 ) .

Figures

FIGURE 1. Doliocarpus stehmannii. A. Fertile branch. B. Leaf, abaxial view. C. Detail of the petiole, abaxial view. D. Flower in pre anthesis. E–F. Sepal. E. Abaxial view. F. Adaxial view. G. Petal in adaxial view. H. Stamen. I. Ovary. J. Detail of an infructescence. K. Fruit. L–M. Seed. L. Covered by aril. M. Without aril.

FIGURE 2. A–I. Doliocarpus stehmannii. A. Climbing mechanism. B–C. Stem. B. Bark. C. Stem cross-section. D. Branches. E–F. Leaf. E. Adaxial view. F.Abaxial view. G. Branchlet and petioles. H–I. Fruiting branch. H. Frontal view. I. Back view showing sepals position. (Photos by João Monzoli).

FIGURE 3. Geographic distribution of Doliocarpus stehmannii (yellow dots) in the Iron Quadrangle, state of Minas Gerais, Brazil.

FIGURE 4. Habitats of Doliocarpus stehmannii. A–B. Forests in the Peti Environmental Station, São Gonçalo do Rio Abaixo, Minas Gerais, Brazil.A. Margins of Santa Bárbara River.B. Semideciduous Seasonal Forest vegetation and view of a mining activity to the north. C–D. Doliocarpus stehmannii growing inside a Pinus sp. planting plot. (Photos by João Monzoli).