Oxalis kollmannii Fiaschi

Fiaschi, P. 2012. Kew Bulletin 67: 33. https://doi.org/10.1007/s12225-012-9330-3

Morphology General Habit

Unbranched erect herbs, 30 – 50 cm tall; young branches laterally compressed, hirtellous and setulose, with setose trichomes lateral to the pedicel scars, older branches glabrescent, greyish brown, terete, smooth

Morphology Leaves

Leaves pinnate, trifoliolate; spirally alternate, densely grouped at plant apex, internodes 4 ( – 10) mm long; petioles 4.1 – 8.3 cm long, slightly thickened at the base, adaxially canaliculate, very sparsely hirtellous, with intermixed glandular trichomes; rachis 0.9 – 2 cm long, similar to petiole, but slightly wider distally; petiolules 1 – 2 mm long, adaxially sparsely setose or setulose; leaflets glabrous, membranous, adaxially lighter coloured along main vain, abaxially greenish Venation: main vein adaxially prominent or impressed, abaxially prominent; secondary veins 5 – 7, abaxially prominent, reticulation indistinct on both surfaces

Morphology Leaves Leaflets

Lateral leaflets 2.6 – 4 × 1.5 – 2.7 cm, ovate, symmetrical to very slightly asymmetrical, apex rounded, sometimes acute, base truncate to rounded Terminal leaflet 3.7 – 5.3 × 1.8 – 3.6 cm, ovate, apex acute, tip somewhat rounded, base rounded or obtuse

Morphology Reproductive morphology Inflorescences

Inflorescences axillary, comprising dichasial cymes, almost as long or longer than leaves; peduncle 3.7 – 9.1 cm long, more densely hirtellous than petioles, with many glandular trichomes mostly along the distal half; dichasial branches 1.2 – 3 cm long, hirtellous-glandulose, each with 21 – 38 flowers arranged along the entire length; floral bract 0.5 – 1 mm long, narrowly triangular, glandular-setulose

Morphology Reproductive morphology Flowers

Flowers with pedicels 2.5 – 3.5 mm long, basally articulated, hirtellous-glandular

Morphology Reproductive morphology Flowers Calyx

Sepals greenish, 3 – 4 × 0.4 – 1 mm, oblong, internal sepals sparsely glandular along main vein, external sepals hirtellous-glandular throughout, apex acute

Morphology Reproductive morphology Flowers Corolla

Corolla with white lobes, throat with yellow lines, c. 7 mm long; longistylous flowers with long filaments c. 3.2 mm long, glabrous; short filaments c. 1 mm long, glabrous, each with an orange basal gland (callus, following Salter 1944), anthers c. 0.4 × 0.15 mm, ovate; androgynophore c. 0.3 mm long; ovary c. 0.7 mm long, carpels 5, apically free; styles 5, c. 3.5 mm long, densely setose-glandular

Morphology Reproductive morphology Fruits

Capsules c. 2.5 × 2.7 mm, broadly depressed-ovoid, glabrous, distally hirtellous-glandular along carpel abaxial surface; locules one-seeded; seeds c. 2.2 × 1.2 mm, semi-oblate, furrowed along longitudinal lines

Distribution

South America: Brazil, restricted to the vicinities of Santa Teresa, south of the Rio Doce in Espírito Santo state.

Ecology

Found in disturbed areas along roadsides, growing among rock outcrops; 500 – 850 m.

Conservation

Oxalis kollmannii is known from only two locations in close proximity to each other, in a highly fragmented forest habitat that has been suffering a continuous decrease in area, extent and quality. Due to this restricted distributional range, O. kollmannii can be considered as Endangered (EN B1a,b(iii)) following IUCN (2001) categories and criteria.

Phenology

Flowers have been recorded in February, June and December, while fruits have been recorded in December and February.

Note

The epithet honors Ludovic C. Kollmann, who recently collected samples of this new species, and of several other Oxalis species in the surroundings of Santa Teresa, Espírito Santo state. Oxalis kollmanniiFiaschi is similar to O. neuwiediiZucc., from which it can be distinguished by leaves with petioles longer (vs shorter) than laminas, leaflet apices acute, with a rounded tip (vs apex acuminate), and the symmetrical to very slightly asymmetrical (vs clearly asymmetrical) lateral leaflet laminas. Moreover, leaflet laminas in O. kollmannii are glabrous, or with only a few sparsely arranged trichomes along the proximal portion of the midvein and the margin, while in O. neuwiedii trichomes are usually present along the entire leaflet margin. Leaf venation is also adaxially more prominent in O. neuwiedii than in O. kollmannii.