A monograph of the genus Pleiocarpidia K. Sch. (Rubiaceae)

The name Pleiocarpidia was coined by K. SCHUMANN (ENGLER und PRANTL, Natürliche Pflanzenfamilien, Nachträge I, p. 314, 1897) for a genus described in 1873 by HOOKER f. (BENTHAM et HOOKER, Genera Plantarum II (1), p. 71) as Aulacodiscus: HOOKER’S genus had to be rebaptized, because the name Aulacodiscus had been used already in 1844 by EHRENBERG for a genus belonging to the Diatomeae. A proposal made by O. KUNTZE(POST et KUNTZE, Lexicon, 1904) to change the spelling of the name introduced by SCHUMANN in Pliocarpidia can not be accepted, as there is no rule prescribing the transcription of the Greek diphthong in the manner advocated by the proposer. The plant on which HOOKER’S genus was founded, a small tree not uncommon in the Malay Peninsula, had been described already several years before by WIGHT (Calc. Journ. Nat. Hist. VII, p. 144, 1847) under the name Axanthes enneandra. The specific epithet points to the presence of nine stamens in the flower, but this is exceptional: in the flowers investigated by me the ordinary number proved to be seven. The genus Axanthes Bl., to which the species had been referred by WIGHT, was reduced shortly afterwards by BENTHAM and HOOKER f. (Niger Flora,p. 396,1849) and independently by KORTHALS (Ned. Kruidk. Arch. II, 2, p. 194,1851) to Urophyllum Wall. Later HOOKER made an exception for Axanthes enneandra Wight. The flowers of this plant were described by him as 8- to 16-merous, and on account of this character and of the presence of a “peltate stigma” he referred it to a new genus. Afterwards a second species from the same region was described by KING and GAMBLE under the name Aulacodiscus Maingayi, but this proved identical with the first (cf. RIDLEY, Flora of the Malay Peninsula II, p. 64, 1923). A really new species, however, was found in Mindanao: it was described by Merrill as Pleiocarpidia lanaensis.