Jacquemontia aequisepala M.Pastore & Sim.-Bianch.

Pastore M., Simão-Bianchini R. 2016. Jacquemontia aequisepala (Convolvulaceae), a new species from Brazil. Kew Bulletin 71: 26. DOI 10.1007/S12225-016-9640-Y

Type

Type: Brazil, Bahia, Rio de Contas, Harley et al. 54919 (holotype SP!; isotype HUEFS!).

Morphology General Habit

Vine, woody base, stems twining, velutinous to glabrescent; trichomes stellate, 6 – 7 (– 8)-rayed; internodes 1 – 7.5 cm long

Morphology Leaves

Leaf blades 1.5 – 5.8 × 0.8 – 4.2 cm, ovate to lanceolate; base subcordate, truncate or obtuse; margin entire to sinuate; apex obtuse to acute, mucron to 2 mm long; adaxial face dark green, pubescent, abaxial face light green, tomentose to sparse velutinous, trichomes stellate 6 – 7 (– 8)-rayed, rays erect and subequal (c- 0.5 mm long); venation brochidodromous, 5 – 7 pairs of secondary veins; petiole 0.6 – 3.5 cm

Morphology Reproductive morphology Inflorescences

Inflorescences axillary, dichasia corymbiform, 3 – 22-flowered; primary peduncles 0.8 – 9.4 cm, secondary peduncles 6 – 13 mm, both velutinous; bracteoles 1 – 2.5 × 0.5 – 1 mm, lanceolate, pubescent; pedicels 5 – 12 mm, velutinous

Morphology Reproductive morphology Flowers Calyx

Sepals equal to subequal, the outer 4 – 6 × 3.5 – 4 mm, oblong, glabrous or trichomes clustered at the apex, the inner 4 – 6.5 × 4 – 5 mm, ovate, glabrous, both sepals with apex truncate, obtuse to rounded

Morphology Reproductive morphology Flowers Corolla

Corolla 1.5 – 2.5 cm long, infundibuliform, lilac, simple trichomes on apex of midpetaline bands

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens unequal, the longer filaments 13 – 12 mm, the shorter 9 – 10 mm, base glandular-pubescent, anthers c- 1.5 mm; grain pollen spinulose, pantocolpate

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary c- 1.5 mm, glabrous, 2-locular, locules 2-ovulate, nectary disc on the base of the ovary; style 14 – 16 mm; stigmas 2, c- 1.5 mm., ellipsoid, dorsiventrally flattened

Morphology Reproductive morphology Fruits

Fruit capsular, 8-valvate, 6 – 7 mm long, ovoid, persistent sepals partially covering the fruit

Morphology Reproductive morphology Seeds

Seeds 3 – 4 mm long, trigonous, glabrous, rough, margins with small wing c- 0.5 mm

Distribution

Brazil: Bahia (Abaíra, Caetité, Maracás, Mucugê, Piatã, Rio de Contas, and Utinga); Minas Gerais (Diamantina, Grão-Mogol, Medina, and São Gonçalo do Rio Preto).

Ecology

Jacquemontia aequisepala occurs in semi-arid regions, on Campo Rupestre (cerrado of high elevation), on forest edge in caatinga and Seasonal Forest.

Conservation

Jacquemontia aequisepala is widespread in the area of distribution, and currently should not be classified as endangered according to IUCN (2001), although this species occurs in less than 20,000 km2, it exists at more than 10 locations.

Note

The epithet refers to the equal sepals of the plant, whereas other species similar to it have unequal sepals. This character is very important for taxonomic recognition of Jacquemontia species. Specimens of Jacquemontia aequisepala have been identified as J. uleana Hallier f. [= J. frankeana (Schltdl.) M. Pastore & Sim.-Bianch.] by several taxonomists. Examining J. frankeana, it is verified as having stellate trichomes, 4 – 5-rayed, the stems and leaves are glabrescent, the sepals are always unequal, the outer sepal being longer than the inner. Also, J. frankeana has tricolpate pollen grains and occurs from Rio de Janeiro to Santa Catarina, in restinga vegetation (Atlantic Forest). In fact, J. frankeana is more morphologically similar to J. holosericea (Weinm.) O’Donell. Jacquemontia glaucescens is distinguished from J. aequisepala mainly by the indumentum comprising two layers; the lower layer has multi-radiate trichomes, adpressed, and shorter, while the top layer has stellate trichomes, 6 – 8-rayed, erect and longer. The sepals are unequal and the corolla is longer than J. aequisepala. Jacquemontia aequisepala is similar to J. glaucescens Choisy, but differs by usually leaves with obtuse to truncate base (vs cordate base in J. glaucescens), 5 – 7 pairs of secondary veins (vs 7 – 9 pairs of secondary veins), equal or subequal sepals (vs unequal sepals), small corolla 1.5 – 2.5 cm long. (vs 2.5 – 3.5 cm long corolla), and all the trichomes are stellate 6 – 7 (– 8)-rayed (vs multi-radiate mixed with stellate trichomes).