Dichorisandra subtilis Aona & M.C.E.Amaral

Aona, L.Y.S., Faden, R.B. & Amaral, M..C.E. Kew Bull (2011) 66: 479. https://doi.org/10.1007/s12225-011-9308-6

Morphology General Habit

Erect, single stemmed, perennial, completely pilose herb, 18 – 40 cm tall

Morphology Stem

Stem green, hairs 3 – 4 mm long, white; internodes 1.5 – 2 cm long at base, distally shorter

Morphology Leaves

Leaves in rosettes or spirally arranged; sheaths 2 – 2.3 cm long, leaf blade deciduous at base, densely villous, trichomes 2.8 – 3 mm long, margin ciliate, cilia c- 3 mm long; leaf blades sessile or petioles up to 3 mm long; blades elliptic to lanceolate, 11.5 – 17.5 × 4 – 5 cm, base symmetric, margin sparsely ciliolate, apex acuminate, pale green above, dark green beneath, densely pilose on both surfaces, trichomes 2 – 3 mm long

Morphology Reproductive morphology Inflorescences

Inflorescence terminal, dense, erect, subsessile; basal bract leaf-like, short peduncle or with peduncle up to 4 mm long; cincinnus sessile, dense, with 2 – 3 very approximate flowers on each lateral branch; bracts acuminate, 20 × 4 mm, shorter towards the apex, green, becoming scarious, adaxially glabrous, abaxially pilose, ciliate at margin, bracteoles deltoid, 5 – 7 × 2 – 3 mm, margin sparsely ciliate, apex aristate, sparsely pilose, green turning dark brown

Morphology Reproductive morphology Flowers

Flowers bisexual, showy, the androecium slightly zygomorphic, 3 – 3.5 cm in diam., pedicels 2 – 3 mm long, green, pilose; floral buds ovoid, 6 – 9 × 3 – 4 mm; sepals oval, 10 – 11 (– 14) × 5 – 7 mm, white-greenish, pilose on the distal third and along the median vein, margin glabrous; petals unguiculate, limb broadly obovate, 1.6 × 1.7 cm, apical two-thirds purplish, proximal third whitish; stamens 5, unequal, staminode 0.5 mm long or rarely absent, the two superior stamens slightly curved upwards, filaments 1 – 1.5 mm long, adaxial stamen smaller than the others, anthers whitish, apex and centre blue to purplish, 3 – 4.5 mm long, introrsely rimose (functionally poricidal), base cordate to subsagittate; ovary c- 2 × 2 mm, greenish, glabrous, verrucose, with 6 – 7 ovules per locule; style 3 – 6 mm long, almost completely blue to purplish or whitish with lilac stripes from the middle upwards, apex curved; stigma slightly 3-lobed

Morphology Reproductive morphology Fruits

Capsules cylindrical, 10 × 4 mm, epicarp verrucose

Morphology Reproductive morphology Seeds

Seeds unknown

Distribution

Brazil: this species is known only from Bahia state

Ecology

Occurs in the Atlantic moist Forest at 300 m alt.

Conservation

Conservation Status. Endangered (EN B2 ab (ii, iii; IUCN 2001). Dichorisandra subtilis has a very restricted distribution and extent of occurrence (< 20 km2) and is known only from the type locality.

Phenology

This plant was found flowering in October in Bahia, and flowered in January under cultivation at the University of Campinas, State of São Paulo.

Note

Dichorisandra subtilis can be distinguished from the other species of the genus by the combination of extremely small erect habit, an unbranched stem, densely pilose leaves and densely villous leaf sheaths, a congested inflorescence with a very short peduncle, all unusual characters within the genus (Fig. 2A). The flowers of this species are very showy. This new species was first collected by J. G. Jardim in 2001, and brought into cultivation in the glasshouse of the Botany Department at the University of Campinas, where it has flowered many times since 2002. The new species resembles Dichorisandra acaulisCogn. in its small erect habit (up to only 40 cm tall) and dense inflorescence. However, the new species has a short peduncle (vs absent peduncle), five stamens (vs six), introrsely rimose and functionally poricidal anthers (vs anthers apically poricidal) and verrucose (vs smooth) ovary. The Latin adjective subtilis means fine, precise, delicate (Stearn1992).