Survey of the vascular plants of Sierra Chica, the untouched area of the Paititi Natural Reserve (southeastern Tandilia mountain range, Buenos Aires province, Argentina) Author Echeverría, María L. Author Alonso, Sara I. Author Comparatore, Viviana M. text Check List 2017 2017-12-15 13 6 1003 1036 http://dx.doi.org/10.15560/13.6.1003 journal article 10.15560/13.6.1003 1809-127X Lathyrus hookeri Don Figure 20 Lathyrus hookeri Don (1832) : 332 — Cabrera (1967) : 616 ; Flora Argentina (2017) . Lathyrus hookeri Don f. albiflora (O. Kuntze) Burkart , ex : Cabrera (1963) : 616 . Lathyrus sessilifolius Hooker & Arnott (1831) : 20. Figure 20. Lathyrus hookeri . A. Plant. B. Detail of leaves that have turn black after being dried. C. Specimen with white keel and violet standard and wings. D. Specimen with white petals. Cryptophytes; native with distribution in the Southern Cone Region of South America. Characteristics. Perennial twining herb that turns black when it dries. Rhizomes and decumbent tetragone stems with 2 wings in upper stems. Leaves sessile or subsessile, pinnately compound, with 2 oval, slightly glaucous, mucronate leaflets with notable veins, 1–7 ter- minal tendrils, and wide sagittate stipules. Inflorescence: a raceme with 5–10 flowers of lilac to violet petals. Fruit: a linear and erect legume, which turns black at maturity. Comments. This is a frequent species in the study area. It grows in intermediate to full sunlight, on slopes with moderately deep, damp soils. Many species of the genus Lathyrus thrive in the mountain ranges of this region. Lathyrus hookeri can be recognized by the presence of very short petioles (or even sessile leaves) and by its fruit that turns black when dried. In the Paititi Reserve, specimens with violet petals were found, which is typical, and specimens with white petals were also found that, according to Cabrera (1967) , would correspond to L. hookeri Don f. albiflora (O. Kuntze) Burkart. Nowadays , L. hookeri f. albiflora is synonym of L. hookeri Don ( Flora Argentina 2017 ). Besides the white flower specimens, plants with white keel and violet standard and wings were also found. This would be the first record of this variant of L. hookeri .