Occurrence of Morphological and Anatomical Adaptive Traits in Young and Adult Plants of the Rare Mediterranean Cliff Species Primula palinuri Petagna

Figure 1

Developmental stages of P. palinuri plants: (a) germinated seeds with emerging root, hypocotyl ring hairs and hypocotyl; (b)–(d) very young plants at 5–7-leaf stage showing the hypocotyl enlarging into a cone in continuity with the primary root ((c), (d) arrows) and vigorous adventitious roots adjacent to the cone; (e)–(g) very young plants at 10-leaf stage showing the hypocotyl expanded into a round organ with numerous adventitious roots emerging from the base; (h)-(i) young plants with elongated hypocotyl becoming a rhizome; arrows show constrictions marking the probable transition between subsequent years/periods of growth. Bars are 1 mm in a and 0.5 cm in (b)–(i).