FIGURE 2. Kalanchoe ×robertsonii. A. Leaves and stems. At first the leaves are light green to glaucous, later becoming orange-infused, especially towards the leaf margins. The margins are flat and entire for the proximal ⅔–¾, usually with few crenations towards the leaf apex. B. The adaxial surface of the ovate to very slightly elliptic corolla lobes of K. ×robertsonii is bicoloured, i.e., dull to bright light orange distally and strongly yellow-infused proximally. C. Corolla tubes of the nothospecies are shiny light orange and only lightly greeninfused in the lower ½ (flower in the centre), while those of K. longiflora are uniformly shiny greenish yellow (flower on the left) and those of K. rotundifolia are red to dull orange and often strongly green-infused proximally (flower on the right). D. The adaxial surface of the corolla lobes of the nothospecies is dull to bright light orange and strongly yellow-infused (flower in the centre), while that of K. longiflora is monochromatic light yellow (flower on the left) and that of K. rotundifolia is monochromatic red to dull orange (flower on the right). E. The aberrant flower of K. ×robertsonii in the centre is pentamerous, rather than tetramerous as in the case of all Kalanchoe species. Such a deviation in the number of flower parts is often found in interspecific Kalanchoe hybrids. F. Prof. Dr Bruce Leonard Robertson (1944–) after whom K. ×robertsonii is named; photograph taken on 26 May 2019. All photographs: Gideon F. Smith.

Published as part of Smith, Gideon F., 2022, Kalanchoe ×robertsonii [K. longiflora × K. rotundifolia] (Crassulaceae subfam. Kalanchooideae), a new, small-growing nothospecies from South Africa, pp. 85-94 in Phytotaxa 561 (1) on page 89, DOI: 10.11646/phytotaxa.561.1.8, http://zenodo.org/record/7052891