Gymnocalycium gibbosum (Haw.) Pfeiffer, 1844

Echeverría, María L., Alonso, Sara I. & Comparatore, Viviana M., 2017, Survey of the vascular plants of Sierra Chica, the untouched area of the Paititi Natural Reserve (southeastern Tandilia mountain range, Buenos Aires province, Argentina), Check List 13 (6), pp. 1003-1036 : 1024

Gymnocalycium gibbosum (Haw.) Pfeiffer

Figure 29

Gymnocalycium gibbosum (Haw.) Pfeiffer ex Mittler (1844) : 124 — Cabrera (1965b): 285; Flora Argentina (2017); Tropicos (2017).

Cactus gibbosus Haworth (1812) : 173.

Gymnocalycium platense (Speg.) Britton & Rose (1922) : 163 — Cabrera

(1965b): 286.

Gymnocalycium brachypetalum Spegazzini (1925) : 139 — Cabrera

(1965b): 286.

Chamaephytes; native with wide distribution in the Southern Cone Region of South America. Vulnerable, reasons unknown ( Delucchi 2006).

Characteristics. Perennial, glaucous to green herb with greatly enlarged, globose stem, to 20 cm long, 10 cm wide, and 12–16 lobed ribs. Areoles with 7–15 rigid spines. Flowers located in the superior areoles, 6 cm wide. Perianth white; external scales green, with ovate shape and acute apex. Fruit: fusiform or piriform shape.

Comments. This is a frequent species in the study area. It grows in full sunlight conditions in cracks on the slopes. It differs from other Cactaceae from the study area by the color of the flowers; Wigginsia and Parodia species have yellow flowers, while G. gibbosum has white flowers.

Superorder Asteranae

Order Apiales : Family Apiaceae : Tribe Saniculeae