Index Kewensis Supplement twenty one Names of seed-bearing plants at the rank of family and below published between January 1996 and the end of 2000 with some omissions from earlier years - Royal Botanic Gardens, Kew. (Royal Botanic Gardens, Kew)

Index Kewensis plantarum phanerogamarum. nomina et synonyma omnium generum et specierum ab initio anni MDCCCCXXVI usque ad finem anni MDCCCCXXX complectens Supplementum octavum - Royal Botanic Gardens, Kew. (e prelo Clarendoniano)

Mesembryanthemum and some new genera separated from it - Brown, Nicholas Edward, 1849 -1934 (s.n.], 1921)