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GAMETOPHYTE OF LYCOPODIUM DIGITATUM
Author(s) -
Bruce James G.
Publication year - 1979
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1979.tb06333.x
Subject(s) - gametophyte , biology , meristem , botany , lycopodium , pollen , shoot
Gametophytes of Lycopodium digitatum A. Braun are subterranean, mycorrhizal structures. Externally, they are conical and divided into three principal regions: tapering base, ring meristem, and gametangial cap. Internally, the endobiont is restricted to specialized tissues in the base. Gametangia typical of those described for L. complanatum are found along the cap margin near the ring meristem. Comparative analysis of these and other related gametophytes leads to the conclusion that Bruchmann's Type I (L. clavatum) and Type II (L. complanatum) gametophytes cannot be consistently separated on the basis of 1) mycorrhizal tissues, 2) form of gametophyte, and 3) number of neck canal cells in the archegonium, as he had proposed. Consequently, it is suggested on the basis of ring meristem and radial symmetry, mycorrhizal tissue specialization, and lack of sterile paraphyses or lobes that Type I and Type II gametophytes be merged as a single type. The now broadened clavatumcomplanatum type is restricted to subgenus Lycopodium (sensu Wilce) where it is the only known type.