[942] This name has been used for a section of a genus
of recent Umbelliferae but not as a generic name (De Candolle’s ‘Prodromus,’ Pars iv. p. 105, 1830).
[956] In selecting a generic name for a fossil plant or part
of a plant it has not been the universal practice to avoid the use of a designation previously employed for a recent plant. It is clearly
in accordance with the Rules adopted by the International Botanical Congress and with general convenience to avoid the employment of the
same name for two different generic types even if one is known only in a fossil state. My attention has been called by Mr W. N. Edwards
of the British Museum to the fact that the names Platyspermum, Microspermum, and Pterospermum recently proposed by
Dr Arber for Palaeozoic seeds have previously been given to recent flowering plants. Though I have often neglected to consult the Index
Kewensis and the Genera Siphonogamarum before proposing a ‘new’ generic term, I fully recognise the importance of avoiding the
employment of names in current use or names which have ‘lapsed into synonymy[966].’
[972] Brongniart (74) p. 247, Pl. xxi. figs. 12–14;
(81) p. 21, Pl. A. fig. 12; Pl. xiv; Renault (802) p.
106, Pl. xv. figs. 12, 13; Grand’Eury (77) A. p. 239, Pl.
xxvi. fig. 27.