A linear sequence of extant families and genera of lycophytes and ferns Author Christenhusz, Maarten J. M. Botany Unit, Finnish Museum of Natural History, Postbox 7, University of Helsinki, 00014 Helsinki, Finland. & Department of Botany, Natural History Museum, Cromwell Road, London SW 7 5 BD, United Kingdom. Author Zhang, Xian-Chun State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China. E-mail: zhangxc @ ibcas. ac. cn Author Schneider, Harald Department of Botany, Natural History Museum, Cromwell Road, London SW 7 5 BD, United Kingdom. text Phytotaxa 2011 2011-02-18 19 7 54 http://biotaxa.org/Phytotaxa/article/view/phytotaxa.19.1.2 journal article 6238 10.11646/phytotaxa.19.1.2 57ebbaea-ebc2-443f-8066-60a0c5ea774f 1179-3163 4893995 16F684F2-12C4-4A33-9330-062AC1F32FF0 17.2. Salvinia Ség., Fl. Veron. 3: 52 (1754). T.: Salvinia natans (L.) All. ( Marsilea natans L)