Systematics of Korthalsella (Viscaceae)
Description
This work comprises a revision of Korthalsella (Tieghem) Engler. Morphometric study and field work indicated that characters widely used in previous revisions (Danser 1937; Lecomte 1916; Engler 1897; Tieghem 1896) do not consistently delimit species. Anatomical study showed that vascular bundle number in the stems is taxonomically useful at the specific level. Population structure is relatively uniform, as evidenced by electrophoretic data, though differences between populations can be great. Isoenzyme analysis also showed that vegetative morphological variation is not correlated with enzymatic variation. Based on the above work, the genus contains seven species, rather than 24 species (Danser 1937). The following taxa have been recognized: (UNFORMATTED TABLE OR EQUATION FOLLOWS)$$\vbox{\halign{#\hfil&&\quad#\hfil\cr&Section Heterixia Engler (1897)\cr&\qquad{\it Korthalsella geminata}\ (Korthals) Engl.\cr&\qquad{\it Korthalsella papuana} Danser\cr\cr&Section Korthalsella Engler (1897) (as Eu-Korthalsella)\cr&\qquad{\it Korthalsella taenioides} (Commerson ex DC.) Engl.\cr&\qquad\qquad forma {\it remyana} (Tieghem) Molvray\cr&\qquad\qquad forma {\it horneana} (Tieghem) Molvray\cr&\qquad\qquad forma {\it pendula} (Wawra) Molvray\cr&\qquad\qquad forma {\it disticha} (Endl.) Molvray\cr&\qquad\qquad forma {\it emersa} (Barlow) Molvray\cr\cr&Section Bifaria Engler (1897)\cr&\qquad{\it Korthalsella japonica} (Thunb.) Engl.\cr&\qquad\qquad forma {\it rubra} (Tieghem) Molvray\cr&\qquad\qquad forma {\it grayi} (Barlow) Molvray\cr&\qquad{\it Korthalsella salicornioides} (A. Cunn.) Tieghem\cr&\qquad{\it Korthalsella lindsayi} (Oliver ex Hook.f.) Engl.\cr&\qquad{\it Korthalsella lindsayi} var. {\it clavata} (Kirk) Danser\cr&\qquad{\it Korthalsella dacrydii} (Ridley) Danser\cr}}$$(TABLE/EQUATION ENDS)