Cycadophyta

Sago palm Cycas revoluta, from here.

Belongs within: Spermatophyta.
Contains: Encephalartos, Macrozamia, Ceratozamia, Zamia.

The Cycadophyta, cycads, are a group of superficially palm-like gymnosperms. The name 'Cycadophyta' was defined by Cantino et al. (2007) to refer to the cycad crown group, characterised by the presence of cone domes, vascular strands crossing the pith within the stem. These result from the sympodial growth of the plant: each successive cone represents the termination of the apical meristem, and growth is continued through the production of a secondary subapical bud that eventually overtops the old cone and displaces it to one side.

<==Cycadophyta [Cycadales]
    |--Cycas [Cycadaceae, Cycadineae] TK01
    |    |--C. chamaoensis NM11
    |    `--+--C. pectinata NM11
    |       |--+--C. nongnoochiae NM11
    |       |  `--+--C. tansachana NM11
    |       |     `--+--C. condaoensis NM11
    |       |        `--C. elongata NM11
    |       `--+--C. lindstromii NM11
    |          `--+--+--C. clivicola NM11
    |             |  `--C. siamensis NM11
    |             `--+--+--+--C. hongheensis NM11
    |                |  |  `--+--C. petraea NM11
    |                |  |     `--+--C. ferruginea NM11
    |                |  |        `--+--C. panzhihuaensis NM11
    |                |  |           `--+--C. szechunensis NM11
    |                |  |              `--+--C. revoluta Thunberg 1782 NM11,CD07
    |                |  |                 `--C. taitungensis NM11
    |                |  `--+--+--C. fugax NM11
    |                |     |  `--C. hainanensis NM11
    |                |     `--+--C. micholitzii NM11
    |                |        `--+--C. multipinnata NM11
    |                |           `--+--+--C. guizhouensis NM11
    |                |              |  `--+--C. debaoensis NM11
    |                |              |     `--C. diannanensis NM11
    |                |              `--+--+--C. collina NM11
    |                |                 |  `--C. simplicipinna NM11
    |                |                 `--+--+--C. miquelii NM11
    |                |                    |  `--C. sexseminifera NM11
    |                |                    `--+--+--C. aculeata NM11
    |                |                       |  `--C. brachycantha NM11
    |                |                       `--+--+--C. dolichophylla NM11
    |                |                          |  `--C. segmentifida NM11
    |                |                          `--+--C. tropophylla NM11
    |                |                             `--+--C. chevalieri NM11
    |                |                                `--C. tanqingii NM11
    |                `--+--C. macrocarpa NM11
    |                   `--+--C. seemannii NM11
    |                      `--+--+--C. bougainvilleana NM11
    |                         |  `--+--+--C. chamberlainii NM11
    |                         |     |  `--C. riuminiana NM11
    |                         |     `--+--C. litoralis NM11
    |                         |        `--+--C. zeylanica NM11
    |                         |           `--+--C. edentata NM11
    |                         |              `--+--C. rumphii NM11
    |                         |                 `--+--C. thourasica NM11
    |                         |                    `--+--C. micronesica NM11
    |                         |                       `--+--C. circinalis Linnaeus 1753 NM11, CD07
    |                         |                          `--+--C. beddomei NM11
    |                         |                             `--C. sphaerica NM11
    |                         `--+--C. media NM11
    |                            `--+--+--C. apoa NM11
    |                               |  `--C. schumanniana NM11
    |                               `--+--+--C. armstrongii NM11
    |                                  |  `--+--C. manconochiei NM11
    |                                  |     `--C. xipholepis NM11
    |                                  `--+--C. calcicola NM11
    |                                     `--+--+--+--C. cairnsiana NM11
    |                                        |  |  `--C. couttsiana NM11
    |                                        |  `--+--C. platyphylla NM11
    |                                        |     `--C. semota NM11
    |                                        `--+--C. ophiolitica NM11
    |                                           `--+--C. basaltica NM11
    |                                              `--+--C. ensata [=C. media ssp. ensata] NM11
    |                                                 `--C. yorkiana NM11
    `--Zamiaceae [Zamiineae] TK01
         |--+--+--Lepidozamia NM11
         |  |  |    |--L. hopei NM11
         |  |  |    `--L. peroffskyana NM11
         |  |  `--Encephalartos NM11
         |  `--Macrozamia NM11
         `--+--Dioon NM11
            |    |--D. spinulosum NM11
            |    `--+--D. edule NM11
            |       `--+--D. tomasellii NM11
            |          `--+--D. merolae NM11
            |             `--D. purpusii NM11
            `--+--Bowenia NM11
               |    |--B. serrulata NM11
               |    `--B. spectabilis PL12
               `--+--+--Stangeria eriopus NM11
                  |  `--Ceratozamia NM11
                  `--+--Microcycas calocoma NM11
                     `--Zamia NM11

Cycadophyta incertae sedis:
  Taeniopteris Z02
    |--T. daintreei [incl. T. spatulata] F71
    |--T. triassica Walkom 1925 F71
    `--T. vittata T30
  Pterophyllum nathorsti [=Dioonites nathorsti] T30
  Holozamites WL10
  Androstrobus PL12
    |--A. balmei PL12
    |--A. szei PL12
    `--A. wonnacotti PL12
  Delemaya spinulosa PL12

*Type species of generic name indicated

REFERENCES

[CD07] Cantino, P. D., J. A. Doyle, S. W. Graham, W. S. Judd, R. G. Olmstead, D. E. Soltis, P. S. Soltis & M. J. Donoghue. 2007. Towards a phylogenetic nomenclature of Tracheophyta. Taxon 56 (3): E1-E44.

[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1-167.

[NM11] Nagalingum, N. S., C. R. Marshall, T. B. Quental, H. S. Rai, D. P. Little & S. Mathews. 2011. Recent synchronous radiation of a living fossil. Science 334: 796-799.

[PL12] Peñalver, E., C. C. Labandeira, E. Barrón, X. Delclòs, P. Nel, A. Nel, P. Tafforeau & C. Soriano. 2012. Thrips pollination of Mesozoic gymnosperms. Proceedings of the National Academy of Sciences of the USA 109 (22): 8623-8628.

[TK01] Tagashira, N., & K. Kondo. 2001. Chromosome phylogeny of Zamia and Ceratozamia by means of Robertsonian changes detected by fluorescence in situ hybridization (FISH) technique of rDNA. Plant Systematics and Evolution 227: 145-155.

[T30] Thomas, H. H. 1930. Further observations on the cuticle structure of Mesozoic cycadean fronds. Proceedings of the Linnean Society of London 141: 5-7.

[WL10] Wang, Y., Z. Liu, X. Wang, C. Shih, Y. Zhao, M. S. Engel & D. Ren. 2010. Ancient pinnate leaf mimesis among lacewings. Proceedings of the National Academy of Sciences of the USA 107 (37): 16212-16215.

[Z02] Zherikhin, V. V. 2002. Ecological history of the terrestrial insects. In History of Insects (A. P. Rasnitsyn & D. L. J. Quicke, eds) pp. 331-388. Kluwer Academic Publishers: Dordrecht.