Eryngium regnellii Malme

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 : 1024-1025

Eryngium regnellii Malme

Figure 30

Eryngium regnellii Malme (1904) : 9 — Calviño & Martínez (2007): 71;

Flora Argentina (2017); Tropicos (2017).

Hemicryptophytes, native with wide distribution in the Southern Cone Region of South America.

Characteristics. Perennial herbs with rhizomes and erect branches, to 2 m tall. Leaves glabrous, membranous; basal leaves flaccid, linear, with parallel veins and ap- pressed, solitary bristles in the margin (frequently 2 at the base), to 1 m long and 15 mm wide, larger than the caulinar leaves. Inflorescence: a dichotomous cyme, with ovoid, greenish-white capitulums (1.2 × 1 cm). Fruit: a schizocarp composed of 2 mericarps with lateral scales and vesicles on the upper lower surface, rare or absent in the base.

Comments. This is a frequent species in the study area. It grows in full sunlight conditions, in moderately deep, damp soils and in cracks on the slopes. Up to 2007, E. regnellii was confused with E. stenophyllum Urb.

( Calviño and Martínez 2007), a species reported from Buenos Aires province. Eryngium stenophyllum differs from E. regnellii in leaf and mericarp characteristics. It presents coriaceous leaves with 1–3 bristles that are up to 15 mm long at the margin, and mericarps with lateral free scales and a naked lower surface.