CYCADACEAE UPDATED (1999)
D. J. DE LAUBENFELS
Syracuse University, Department of Geography, Syracuse, N. Y. 13244. U. S. A.

Summary: The genus Cycas L. is divided into four subgenera and twenty eight species. A separate Asian genus, Epicycas de Laub., is recognized for several of what were Cycas species or varieties with a subterranean bulbous stem base.  Keys are given for the subgenera and for the species within each subgenus.

Key words: Cycas, Epicycas.

Notes:    
1) Because this article is so long, it has been divided up into sections. Below is an outline; simply click on a section to view it. 

2) A previous version of this article was published as DeLaubenfels, D.J. & F. Adema. 1998. A taxonomic revision of the genera Cycas and Epicycas Gen. Nov. (Cycadaceae). Blumea 43:351-400. It has been changed sufficiently--by the senior author--so as not to infringe on the copyright held by the scientific journal, Blumea, on the original article (cited above). It is reprinted here with the senior author's permission.

INTRODUCTION
DIVISION OF CYCAS INTO TWO GENERA
CYCADACEAE
    KEY TO THE GENERA

CYCAS
SUBDIVISIONS OF THE GENUS
    KEY TO THE SUBGENERA

    1. SUBGENUS CYCAS
        KEY TO THE SPECIES
        1.  Cycas circinalis L.
        2. Cycas sphaerica Roxb.
        3. Cycas thouarsii Desf. ex Gaudich
        4.  Cycas media R. Br.
        5.  Cycas angulata R. Br.
        6.  Cycas lane-poolei Gardner
        7. Cycas normanbyana Mueller
        8.  Cycas furfuracea Fitzgerald

    2. SUBGENUS TRUNCATA
        KEY TO THE SPECIES
        9. Cycas rumphii Miquel
        10. Cycas scratchleyana Mueller
        11. Cycas celebica Miquel
        12. Cycas silvestris Hill
        13. Cycas edentata de Laub.
        14. Cycas schumanniana Lauterbach in Schumann & Lauterbach

    3. SUBGENUS PECTINATA
        KEY TO THE SPECIES
        15. Cycas pectinata Hamilton
        16.  Cycas taiwaniana Carruth.
        17. Cycas szechuanensis Chen & Fu
        18. Cycas campestris Hill
        19. Cycas javana (Miq.) de Laub. in Wang et al.
        20. Cycas macrocarpa Griff.
        21. Cycas riuminiana Porte ex Regel

    4. SUBGENUS REVOLUTA
        KEY TO THE SPECIES
        22. Cycas revoluta Thunb.
        23. Cycas taitungensis Shen, Hill, Tsou, & Shen
        24. Cycas wadei Merrill
        25. Cycas immersa Craib
        26. Cycas beddomei Dyer
        27. Cycas calcicola Maconochie
        28. Cycas cairnsiana Muell.

EPICYCAS
    KEY TO THE SPECIES
    1. Epicycas micholitzii (Dyer) de Laub.
    2. Epicycas multipinnata (Chen & Yang) de Laub.
    3. Epicycas tonkinensis (Lind. & Rod.) de Laub.
    4. Epicycas miquelii (Warburg) de Laub.
    5. Epicycas elongata (Leandri) S. L. Yang in de Laub. & Adema
    6. Epicycas siamensis (Miq.) de Laub.
    7. Epicycas lindstromii (Yang, Hill & Hiep) de Laub.

REFERENCES

INDEX OF NAMES

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