Mansoa paganuccii M.M.Silva-Castro, 2016

Silva-Castro, Milene Maria Da & Queiroz, Luciano Paganucci De, 2016, Five new species of Mansoa DC. (Bignoniaceae) from South America, Phytotaxa 258 (1), pp. 49-62 : 59-61

Mansoa paganuccii M.M.Silva-Castro , sp. nov. ( Figs. 3 F–H ; 7 )

Similar to Mansoa difficilis ( Chamisso 1832: 714) Bureau & Schumann (1896: 201) with which it shares ovate to elliptic leaflets, but differs by the irregularly serrate margins (vs. entire margins in M. difficilis ), capsules with irregularly constricted margins (vs. entire margins in M. difficilis ), bark not striated (vs. striated in M. difficilis ), and calyx with 5-mucronate rim, with veins slightly extended beyond the rim (vs. 5-dentate calyx, with veins slightly extended beyond the lobe apex in M. difficilis ).

Type:— BRAZIL, Bahia: Igaporã, ca. 9.2 km do trevo para Igaporã-Tanque Novo , 22 April 2008, M. M. Silva-Castro, A. L. Côrtez, M. D. Moura & B. M. Silva 1459 (holotype HUEFS!; isotypes ALCB!, CEPEC!, HRB!, HUESB!, HST!, NY!, MO!, SPF!) .

Lianas without noticeable odor; branches not viscid, cylindrical, glabrous, interpetiolar areas lacking nectary fields, bark conspicuously striated; prophylls of the axillary buds 2–2.3 mm long, obovate, puberulous. Leaves 2–3-foliolate; petiole 1.5–2 cm long, puberulous; petiolule of the distal leaflet 1.5–1.8 cm long, that of the lateral leaflets 0,5–0,6 cm long, puberulous, without indentations or wrinkles; leaflets 2.4–4.5 × 2–2.8 cm, chartaceous, ovate to elliptic, apex acute, obtuse or rounded, sometimes mucronulate, margins plain, irregularly serrate, base cuneate, 3-nerved, concolorous, adaxial surface glabrous, puberulous or sparsely lepidote, abaxial surface glabrous or lepidote, patelliform nectaries at the axil of the main veins near the leaflet base; tendrils trifurcate. Thyrses terminal or axillary, lax, multi-flowered, main axis 2–6 cm long, cylindrical. Calyx 4–5 × 4–5 mm, green, sometimes becoming purple toward the apex, coriaceous, campanulate, truncate and 5-mucronate, venation prominent or not, pubescent, without nectaries; corolla 4–6 × 3–4.5 cm, purple with yellow tube, membranaceous, tubular-campanulate, externally glabrous at the middle two-thirds and pubescent at the distal third, lobes truncate to emarginate; stamens included, dorsal filaments 2–2.4 cm long, ventral filaments 1.5–1.7 cm long, connective elongated, pubescent, thecae 3–3.5 mm long; staminode 1–1.3 mm long; nectariferous disk 1–1.3 mm long, 2–2.4 mm diam., annular; ovary: 2.5–2.8 × 0.8–1 mm, cylindrical, lepidote, with 2-series of ovules per locule, style 2.5–3 cm long, stigma 2–2.3 mm long, lanceolate. Capsule (mature) 12–21.5 × 1.1–1.3 cm, linear, cylindrical, apex acuminate, margins irregularly constricted, base attenuate; valves chartaceous, not striated, not verrucose, glabrous, veins prominent, without ribs; calyx not persistent. Seeds 1–1.5 × 3.5–4 cm, transversally elliptic, thin; embryo nucleus rounded, chestnut colored, 1–1.5 cm wide; wings hyaline, light brown.

Distribution:—This species is found in Caatinga vegetation of Northeastern Brazil, where it occurs in the states of Rio Grande do Norte, Ceará, Piauí, Pernambuco, Bahia, and northern Minas Gerais ( Fig. 2E ).

Phenology:—Flowers are recorded throughout the year but with a peak from March to July. Fruits are found from November to December and from April to August.

Conservation status:—Least concern(LC; IUCN 2012). Mansoa paganuccii is widespread throughout northeastern Brazil and may be found in several protected areas.

Etymology:—The species honors Luciano Paganucci de Queiroz for his significant contributions to our knowledge of the flora of the Caatinga biome.

Notes:— Mansoa paganuccii is characterized by its bark with prominent stripes, interpetiolar fields without nectaries, leaflets with irregularly serrate margins, truncate calyx, with extended veins forming a 5-mucronate rim, purple corolla, stamens with an elongated and pubescent connective, and linear cylindrical capsules, with irregularly constricted margins. No discernible odor was detected, in contrast to most other species of the genus that are marked by a garlic or onion odor.

Mansoa paganuccii was frequently confused with several other species of Mansoa , mainly Mansoa angustidens (Candolle 1896: 200) Bureau & Schumman (1896: 200) and M. difficilis . A.H. Gentry (in sched.) had annotated several specimens with the unpublished name “ Mansoa asperulum (Bureau & K. Schum.) A. H.Gentry ” based on Adenocalymma asperulum Bureau and Schumann (1896: 113) , a species now considered as a synonym of Mansoa angustidens (Lohmann 2015) . Adenocalymma asperulum is known only by the type (Glaziou 11231: P!, R!) collected in coastal wet forest of Araruama, Rio de Janeiro state, far removed from the range of M. paganuccii in Northeastern Brazil. Mansoa paganuccii is similar to M. angustidens in its linear capsules with constricted margins. It differs from both M. angustidens and Adenocalymma asperulum (if distinct from M. angustidens ) by the leaflets with irregularly serrate margins (vs. leaflets with entire margins in M. angustidens ), calyx truncate, 5-mucronated and without nectaries (vs. calyx with extended sepal veins and nectaries in M. angustidens ). Furthermore, M. angustidens occurs exclusively in the rainforests of the Amazonian region of Brazil.

Mansoa paganuccii is also similar to M. difficilis with which it shares ovate to elliptic leaflets. Both species also lack a garlic odor but differ by the leaflets with irregularly serrate margins (vs. leaflets with entire margins in M. difficilis ), capsules with irregularly constricted margins (vs. capsules with entire margins in M. difficilis ), and by the conspicuously striated bark (vs. non-striated bark in M. difficilis ). Mansoa difficilis occurs in rainforests, from southeastern Brazil to Bolivia, Paraguay and Argentina, whereas M. paganuccii is found exclusively in Seasonally Dry Forests of northeastern Brazil.

Additional specimens examined (paratypes):— BRAZIL. Bahia: Caetité, estrada para Caetité , ca. 35 km W, 10 April 2007, M. M. Silva-Castro, L. P. Queiroz, D. Cardoso & R.M. Santos 1157 (HUEFS) ; Gentio do Ouro, Estrada Ipupiara-Gentio do Ouro , ca. 5 km depois de Ipupiara, 22 July 2000, K. R. B. Leite, M. M. Silva, N. R. S. da Cruz & L. Rios 95 (CEPEC, HUEFS) ; Umburanas, Serra do Curral Feio (locally known as Serra da Empreitada ), entrando para W a cerca de 20 km S de Delfino na estrada para Umburanas , 10 April 1999, L. P. Queiroz, M. M. Silva, R. P. Oliveira & C. Correia 5276 (ESA, HUESB, HUEFS, UB). Ceará: São José do Belmonte , entre São José do Belmonte e Jatí, 13 May 1978, E. P. Heringer 735 (IPA, RB, MO, UB). Minas Gerais: Matias Cardoso, sentido Manga, Parque Lagoa do Cajueiro , 22 April 2006, D. S. Carneiro-Torres, F. França & E. Melo 743 (HUESB, HUEFS, MO) .

Figures

FIGURE 2. Distribution range of the newly described species of Mansoa. A. Mansoa gentryi. B. Mansoa ivanii. C. Mansoa longicalyx. D. Mansoa minensis. E. Mansoa paganuccii.

FIGURE 3. Mansoa ivanii. A. detail of the calyx. B. flower. C. capsule. M. minensis. D. detail of the calyx. E. corolla. M. paganuccii. F. detail of the calyx. G. corolla. H. capsule. (Photos by MMSC).

FIGURE 7. Mansoa paganuccii. A. flowering branch. B. calyx. C. open corolla with included androecium. D. detail of the connective. E. nectariferous disk and pistil. F. ovary cross-section showing 2-series of ovules per locule. G. capsule. H. seed. (Drawn by Ivan Farias Castro; from: M. M. Silva-Castro 1458).