Mansoa longicalyx 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 : 55-57

Mansoa longicalyx M.M.Silva-Castro , sp. nov. ( Fig. 5 )

Similar to Mansoa hirsuta with which it shares the ovate to elliptic pubescent leaflets but differs by the 5-laciniate and longer (ca. 3 cm) calyx (vs. 2–3-laciniate and shorter, ca. 2 cm, calyx in M. hirsuta ) and the long inflorescences, ca. 45 cm long (vs. 8–12 cm long in M. hirsuta ).

Type:— BRAZIL, Bahia: Caetité, Estrada a Brejinho das Ametistas, 29 April 2001, C. Correia, A. M. Giulietti & T. R. S. Silva 51 (holotype HUEFS!; isotype CEPEC!) .

Lianas, of unknown odor; branches not viscid, cylindrical, pubescent, interpetiolar area lacking nectary fields, bark striated; prophylls of the axillary buds absent. Leaves 2-foliolate; petiole 2.5–3 cm long, puberulous; petiolules 0.5– 0.8 cm long, puberulous, without indentations or wrinkles; leaflets 5.9–6.2 × 3.2–3.6 cm, coriaceous, ovate, apex acute, mucronulate, margins entire, revolute, base cordate, 5-nerved, concolorous, adaxial surface pubescent, abaxial surface tomentose, nectaries at the axil of main veins near the leaflet base; tendrils not seen. Thyrses terminal, lax, multi-flowered, main axis ca. 45 cm long, cylindrical. Calyx 2.8–3.1 × 1.2 cm, green, membranaceous, cylindrical, lacinia 5, acuminate, longer than the calyx tube, venation prominent, veins extended above the lacinia apex when in bud, 2–3 mm long, puberulous, without nectaries; corolla ca. 8 × 3–5 cm, purple with whitish tube, membranaceous, infundibuliform, externally glabrous at the basal half and pubescent at the distal one, lobe apices rounded; stamens included, dorsal filaments 3–3.4 cm long, ventral filaments 2.3–2.5 cm long., connective elongated, pubescent, thecae 5–6 mm long; staminode 5–6 mm long; nectariferous disk 2–2.5 mm long, 4–5 mm diam., annular; ovary 4–4.3 × 2–2.5 mm, cylindrical, lepidote, 2-series of ovules per locule, style 4.9–5.3 cm long, stigma 5–6 mm long, lanceolate. Fruit and seeds not seen.

Distribution:—Known only from Caatinga vegetation of Caetité, Bahia, Brazil ( Fig. 2C ).

Phenology:—Flowers observed in April.

Conservation status:—It was assessed as critically endangered (CR) according to Criteria B2a, b.iv ( IUCN 2012). It is known only from the type collection, near Caetité. Four field trips during the flowering season in three consecutive years were unsuccessful in recollecting this species. The location where the type was collected is currently deforested.

Etymology:—The specific epithet refers to its calyx, corresponding to 1/3 of the corolla size and proportionally longer than those of the calyces found in other species of Mansoa .

Notes:— Mansoa longicalyx is distinguished by its long multi-flowered and lax inflorescences with ca. 45 cm long, by its large flowers and the long calyx (2.8–3.1 cm), with long and acuminate lacinia, veins extended beyond the lacinia apex when in bud, purple corolla (8–8.5 cm long), and pubescent and elongated stamen connective.

This species is similar to M. hirsuta , with which it shares ovate and pubescent leaflets. It differs from M. hirsuta and from other species of the genus by its cylindrical, 5-laciniate calyces, corresponding to approximately 1/3 of the corolla size (ca. 3 cm in length). Mansoa standleyi (Steyerm. in Standley & Steyermark 1947: 235) Gentry (1979: 783) also presents proportionately large calyces in relation to its corolla, but its calyx is never longer than 1.5 cm and has truncate lobes. Mansoa standleyi is restricted to Central America and northern South America.

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 5. Mansoa longicalyx. A. flowering branch. B. calyx. C. nectariferous disk and pistil. D. ovary cross-section showing 2-series of ovules per locule. (Drawn by Ivan. Farias Castro; from C. Correia et al. 51).