Oxybasis halophila (Phil.) Uotila, 2022

Uotila, Pertti, 2022, New combinations and notes on Oxybasis (Amaranthaceae) from southern South America, Candollea 77 (1), pp. 9-16 : 12

Oxybasis halophila (Phil.) Uotila , comb. nov.

 Chenopodium halophilum Phil. in Anales Univ. Chile 18: 67. 1861.  Chenopodium macrospermum subsp. halophilum (Phil.) Aellen in Repert. Spec. Nov. Regni Veg. 26: 42. 1929.

Lectotypus (designated here): CHILE. Reg. Los Lagos: Llanquihue, Coihuín, prope Puerto-Montt , s.d., Fonk s.n. ( SGO [ SGO000001634 ] image!; isolecto-: [ SGO000001635 ] image!) .

Distribution and ecology. – Oxybasis halophila is known from a very limited area in the Llanquihue Province of Chile. In addition to five specimens from Coihuín, TRONCOSO (1974) cited a specimen from Palena; all specimens seem to come from brackish water shores.

Notes. – REICHE (1911) treated Chenopodium halophilum Phil. as an accepted species and included Blitum salsum Phil. in its synonymy. AELLEN (1929) related Chenopodium halophilum to C. macrospermum Hook. f. and proposed the combination C. macrospermum subsp. halophilum (Phil.) Aellen. In this regard, TRONCOSO (1974) pointed out that these authors had not studied the type material of these species and were not aware of the essential differences in their flower and seed characters. Aellen, in his last letter to Troncoso dated 2 August 1972, agreed that the morphological differences justified the separation of C. halophilum and Blitum salsum at specific level. However, once again, they have recently been considered conspecific and included in the synonymy of Oxybasis macrosperma (Hook. f.) S. Fuentes et al. (e.g. MÚLGURA & GALARZA, 2014; BRIGNONE, 2020).

Oxybasis halophila is here treated as an accepted species distinct to O. macrosperma mainly on the basis of the seed position (practically all horizontal in O. halophila vs. practically all vertical in O. macrosperma ). Indeed, they belong to two different sections, O. halophila having greater affinity with O. ambigua (R. Br.) de Lange & Mosyakin. Furthermore , the broadly rhombic-ovate, slightly 3-lobed middle leaves with almost entire margins and roundish apex distinguish this species from the other Oxybasis taxa ( Table 1).

The specimens SGO000001634 and SGO000001635 were cited as syntypes of Chenopodium halophilum by MUÑOZ PIZARRO (1960) and TRONCOSO (1974). Although the label information of the two specimens does not perfectly match one another, they most probably correspond to the same collection as indicated by the same phenology, size, habit, and preservation conditions. The specimen SGO000001634 is designated here as the lectotype because it bears the original label.

Additional specimen examined. – CHILE. Reg. Los Lagos: Llanquihue,

Coihuín, prope Puerto-Montt, II.1868, Anon. s.n. ( BM, K) .