Stellaria laevis (Bartl.) Rohrb.

Montesinos-Tubée, Daniel B. & Borsch, Thomas, 2023, Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae), Willdenowia 53 (3), pp. 115-148 : 134

9. Stellaria laevis (Bartl.) Rohrb. in Linnaea 37: 275. 1872

≡ Cherleria laevis Bartl. in Presl, Reliq. Haenk. 2: 12. 1831 ≡ Pycnophyllopsis laevis (Bartl.) Timaná in Lundellia 20: 8. 2017.

– Lectotype (designated by Timaná 2017: 8): Peru, Quebrada de l’Obrachillo, s.d., Haenke s.n. ( PR not seen; isolectotypes: GOET 000715 !, HAL 0117903 image!) .

= Cherleria bisulca Bartl. in Presl, Reliq. Haenk. 2: 12. 1831, syn. nov. ≡ Arenaria bisulca (Bartl.) Fenzl ex Rohrb in Linnaea 37: 248. 1872. – Type: Peru, Peru, 1791, T. P. X. Haenke s.n. (HAL01178886 [image!]).

Morphological description — See Timaná (2005).

Distribution — The species inhabits highland plateaus of the central Andes in Peru, at altitudes of 4660–4800 m, in the Lima and Junín departments. The environments where the species grows are highland plateau Andean grasslands with rocks, with template and harsh wind conditions.

Notes — Mattfeld (1934) tentatively included the species described by Bartling (1831) under the genus Cherleria into Plettkea . Mattfeld considered the characters mentioned in the original description as he had no access to specimens. Rohrbach (1872) transferred the species to Stellaria without further reference. Timaná (2017) encountered the Haenke specimen at PR and respective duplicates at HAL and GOET and argued that the species belongs to Pycnophyllopsis . The examination of the type specimen at GOET showed the presence of hirsute leaf margins, apetalous flowers supporting the position in the Plettkea clade. In the ITS tree specimen CAR 912 of S. laevis is resolved as sister to S. cryptantha , albeit with low support (it was not possible to amplify plastid regions in this specimen). The examination of the type specimen further revealed the similarity with Arenaria bisulca (Bartl.) Fenzl & Rohrb. A species also described by Bartling (1831) under Cherleria , which is therefore put into synonymy in this study. Also, Zanotti & al. (2022) discussed if S. laevis could be closely related to Arenaria bisulca , an opinion to which we agree with due to the exact match of morphological characters. Moreover, S. laevis appears to be morphologically similar to S. andina having several differences such as the habit and growth form (loose mat-forming herb vs. weak herbs S. andina ), leaf form and stiffness (rigid in S. laevis vs. weak in S. andina ) and minor flower characteristics. Sequence data of ITS resolve S. laevis as part of subclade A within the Plettkea clade of Stellaria (Supplementary appendix S9).