Two new species of Apodytes (Icacinaceae) from southern Africa

Abstract

Apodytes abbottii Potgieter & Van Wyk and A. geldenhuysii Van Wyk & Potgieter, two new species from southern Africa, are described, illustrated and compared with the other African members of the genus. A. abbottii is a shrub or small tree endemic to rocky sandstone outcrops in southern Natal and north-eastern Transkei (Pondoland Centre). It is probably allied to the widespread A. dimidiata E. Mey. ex Arn. subsp. dimidiata, with which its range overlaps. Diagnostic characters of A. abbottii include its robust though often stunted habit, thick and rigid blue-green leaves which are rounded, erect terminal inflorescences and glabrous ovaries. A. geldenhuysii is a rare multistemmed shrub or small slender tree confined to a small area in the mountains of the south-western Cape. It is a very distinctive species without any close relatives. The few-flowered axillary racemes, unusual pale green and translucent colour of the ripe fruit appendage, intercellular pectic protuberances in the mesophyll of the leaf lamina, and fibres (in addition to sclereids) in the secondary phloem, immediately distinguish it from all other African members of the genus. Other diagnostic characters include the relatively small ovate to ovate-elliptic leaves with retuse apices, blunt-tipped cylindrical flower buds, glabrous ovaries and narrowly oblong off-white petals which are strongly recurved with markedly incurved apices. Apodytes abbottii Potgieter & Van Wyk en A. geldenhuysii Van Wyk & Potgieter, twee nuwe spesies uit Suider-Afrika, word beskryf, geïllustreer en met die ander lede van die genus in Afrika vergelyk. A . abbottii, ’n struik of kleinerige boom, is endemies tot rotsagtige sandsteendagsome in Suid-Natal en Noordoos-Transkei (Pondoland-sentrum). Dit is moontlik naverwant aan die wydverspreide A. dimidiata E. Mey. ex Arn. subsp. dimidiata wat in dieselfde gebied aangetref word. Diagnostiese kenmerke van A. abbottii sluit in die robuuste dog dikwels verpotte groeivorm, dik, stewige, geronde blougroen blare, regop eindstandige bloeiwyses en gladde vrugbeginsels. A. geldenhuysii is ’n seldsame meerstammige struik of klein slanke boom wat slegs in ’n beperkte gebied in die berge van die Suidwes-Kaap aangetref word. Dit is ’n hoogs kenmerkende spesie sonder enige naverwante. Die min-blommige okselstandige raseme, ongewone liggroen en deurskynende ryp vrugaanhangsels, intersellulêre pektiese uitsteeksels in die mesofil van die blaarlamina, en vesels (bo en behalwe sklereïede) in die sekondêre floëem, onderskei dit van al die ander verteenwoordigers van die genus in Afrika. Ander diagnostiese kenmerke sluit in die relatief klein eierronde tot eierrond-elliptiese blare met ingekeepte punte, stomppuntige silindriese blomknoppe, gladde vrugbeginsels en smal-langwerpige witterige kroonblare wat sterk teruggebuig is met opvallende ingekromde punte.