Oxalis hepatica Norlind (1915: 14

Nuernberg-Silva, Anelise & Fiaschi, Pedro, 2021, Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae), Phytotaxa 529 (1), pp. 125-159 : 139

4. Oxalis hepatica Norlind (1915: 14 , lam. 3, fig. 3). Type (lectotype designated by Lourteig 1983: 51, first-step; secondstep designated here):— BRAZIL. Paraná: Itaperussu, 18 November 1908, P. Dusén 7073 (S-R-9771 [web]! Image of the lectotype available at https://plants.jstor.org/stable/viewer/10.5555/al.ap.specimen.s-r-9771; isolectotypes:S-13- 11602 [web]!, S-13-11603 [web]!, K000531580 [web]!) (figs. 6, 9).

Stoloniferous herb. Stem slender, up to ca. 70 cm long, reddish, glabrous or with hairs ca. 0.1 mm long, patent, occasional; internodes 1.5–10.2 cm long, nodes radicant. Stipules ca. 3.5 × 2 mm, semicircular, connate to the petiole, hairs ca. 1 mm long, sparse, purplish; petioles 5–28 cm long; shorter hairs ca. 0.1 mm long, patent, moderate to abundant; longer hairs ca. 0.6 mm long, patent, occasional, with apex purplish; pulvina ca. 1 mm long, hair ca. 1 mm long, patent, moderate. Leaf blades 1.1–3.1 × 1.2–3.1 cm, coriaceous, widely depressed obovate to very widely obovate, discolorous, adaxial surface dark green, abaxial purplish, the base cuneate, the apex rounded or truncate, sometimes retuse, glabrescent; shorter hairs ca. 0.1 mm long, appressed, occasional on both surfaces; longer hairs ca. 0.5 mm long, appressed, sparse along veins on both surfaces, abundant at margin. Dichasia with 8 flowers, shorter than the leaves; peduncle 1–6.7 (11) cm long; shorter hairs ca. 0.1 mm long, patent, moderate to abundant; longer and glandular hairs ca. 0.5 mm long, patent, occasional; bracts 1–4 × 0.5–1 mm, lanceolate, hairs ca. 0.3 mm long, patent, sparse; bracteoles 1–2 × 0.3–0.5 mm, lanceolate. Pedicels 1–14 mm long; sepals 3–4 × 1 mm, reddish, base rounded, apex acute, short hairs ca. 0.1 mm long, moderate to abundant, longer and glandular ca. 0.3 mm long, patent, occasional to sparse; petals yellow, 9–11 mm long, spatulate, the apex crenate-denticulate, adaxially with glandular hairs sparse; shorter stamens ca. 4 mm long, glabrous, longer hairs ca. 6 mm long, hairs ascending; mid-styled pistil ca. 5 mm long, hairs ascending, abundant, stigmas papillose. Capsules 4–5(6) × 4–5 mm., very widely ovoid, 5-lobed, hairs ca. 1 mm long, ascending and patent, abundant. Seeds 1 per locule, ca. 2.9 × 2.1 mm, widely elliptic to elliptic, the base rounded, the apex acute, surface crested.

Distribution and habitat: —This species is endemic to Curitiba area, where it is always associated to forests dominated by Araucaria angustifolia (Bertol.) Kuntze , regarded as mixed ombrophilous forests ( IBGE 2012).

Phenology: —Flowers and fruits have been collected from September to December.

Conservation status: —The habitat of the species is severly threatened, because Araucaria forests remain in good state of conservation for about only 1% of its original cover. It has been historically sampled in four localities in the surroundings of Curitiba (Paraná state), but at least one of these was probably extinct due to recent urban expansion. It has never been recorded at protected areas. Due to its EOO = 581 km ² and AOO = 16 km ², with the original habitat severely fragmented, and with an observed decline in extent of occurrence and habitat quality, we recommend its categorization as Endangered [EN B1B2a,b(iii)].

Nomenclatural notes: — Norlind (1915: 14) originally reported two gatherings, i.e. Dusén 7073 and 7140. Lourteig (1983: 51) carried out a lectotypification indicating Dusén 7073 as the “ holotype ” (Art. 9.10) (she did not mention the collection Dusén 7140). We traced four specimens of Dusén 7073, three at S (S-R-9771, S-13-11602, S-13-11603) and one at K (K000531580) (cf. Art. 9.22). To narrow the choice to a single specimen, a second-step typification is proposed following Art. 9.17 of ICN. The specimen S-R9771 fits unequivocally the original description and was selected as the second-step lectotype for bearing the best-preserved branch, with leaves of different sizes.

Taxonomic notes: — Oxalis hepatica is similar to Oxalis bifrons , from which it can be distinguished by being glabrescent plants (vs. with moderate hairs in O. bifrons ), with up to 8-flowered (vs. up to 13-flowered) inflorescences and leaflets with the abaxial surface purplish (vs. light green in O. bifrons ).

Specimens examined: — BRAZIL. Paraná: Araucária , 12 August 1951, L . Camargo s.n. ( SP56306 ); Curitiba, Bacacheri , 13 October 1970, G . Hatschbach 24919 ( MBM, P); 2 December 1970, G . Hatschbach 25726 ( MBM, P); Tijucas do Sul, Lagoinha , estrada para Saltinho, 2 September 1986, G . Hatschbach 50997 ( MBM, MO [web], P, US [web]) ; 25°55’2.68’’S, 49°13’3.65’’W, 30 September 2016, A . Nuernberg et al.1800 ( FLOR) .