Korthalsella sp.

Pole, Mike, 2022, A vanished ecosystem: Sophora microphylla (Kōwhai) dominated forest recorded in mid-late Holocene rock shelters in Central Otago, New Zealand, Palaeontologia Electronica (a 1) 25 (1), pp. 1-41 : 13

Korthalsella sp.

Figure 13

Material. Present in 5% of the shelters with dry vegetation. Shelter-006, LX5567, Shelter-007, SL 6481, Shelter-029: LX5799, LX5807, LX5803; Shelter-077, LX2552, Shelter-082, LX2450.

Remarks. Four fragments of shelter floor and two coprolite cuticles have paracytic stomata with clearly visible guard cells. The polar ends of the stomatal complexes are typically flat, while the sides curve out. The stomata are sometimes in short but distinct rows of epidermal cells, and are clearly oriented transverse to the row, while a few stomates can be perpendicular to the trend. In other areas of cuticle there are no distinct epidermal rows, and stomatal orientation is not clearly aligned. The cuticle is identified as the mistletoe Korthalsella . In reference material of extant Korthalsella , this range of stomatal distribution and orientation reflects location‒near the leaf base, the stomates and intervening epidermal cells are in clear files but become less clear away from the base. No other New Zealand Loranthaceae genera have this cuticle morphology. For example, Ileostylus micranthus , a broad-leaved mistletoe found in wetter vegetation peripheral to the study area, has randomly oriented stomatal complexes. Three species of Korthalsella currently occur in the study area ( Sultan, 2014), but distinguishing between them on cuticle fragments is not attempted.

Figures

FIGURE 13. Loranthaceae (Korthalsella and Illiostylus) cuticle morphology (Transmitted light microscopy). A. Korthalsella sp., showing generally aligned stomatal complexes (LX2450, Shelter-82, scale bar equals 100 μm). B. Korthalsella sp., detail showing a single stomatal complex (LX2450, Shelter-82, scale bar equals 40 μm). C. Korthalsella sp., showing stomatal orientation perpendicular to epidermal cell rows (LX3371, Coprolite-79, scale bar equals 100 μm). D. Korthalsella sp., detail of stomatal complex (LX3371, Coprolite-79, scale bar equals 40 μm). E. Korthalsella salicornioides for comparison (Herbarium specimen, OPH9239, scale bar equals 100 μm). F. Korthalsella salicornioides for comparison (Herbarium specimen, OPH9239, scale bar equals 40 μm). G. Illiostylus micranthus for comparison (Herbarium specimen, OPH8301, scale bar equals 100 μm). H. Illiostylus micranthus for comparison (Herbarium specimen, OPH8301, scale bar equals 100 μm).