Senecio grisebachii Baker var. subincanus Cabrera

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 : 1028-1029

Senecio grisebachii Baker var. subincanus Cabrera Figure 39

Senecio grisebachii Baker var. subincanus Cabrera (1950) : 70 —

Cabrera (1963): 315; Hurrell (2013): 242; Zuloaga et al. (2014b):

123; Tropicos (2017).

Senecio grisebachii Baker , ex Martius (1884): 313.

Chamaephytes; endemic to mountain ranges of Buenos Aires province.

Characteristics. Perennial herb with erect stems, to 1 m tall. Leaves with lanceolate shape, acute apex, attenuate base and serrate margin. Adaxial leaf surface lanose to glabrous; abaxial leaf surface tomentose, white. Inflo- rescence: radiate capitulums with ray yellow outer florets,

Comments. This is a frequent species in the study area. It grows in full sunlight conditions in deep to moderately deep soils or in deep cracks on grassland slopes. It can be recognized by its densely glandular hairs, entire or dentate leaf margin and 14–15 mm tall involucre. and yellow tubular disc florets disposed in cymose-cor- ymb inflorescences at the end of the branches; phylla- ries densely covered with white tomentose hairs. Fruits: achenes with sericeous pubescent surface and white pappus.

Comments. This is an infrequent species in the study area. It grows in full sunlight conditions in cracks on the summit. Senecio grisebachii var. subincanus is the only variety of S. grisebachii that has been recorded in the region. It can be recognized by its tomentose, not glandular hairs and its pubescent achenes.