Morphological and Anatomical Features of Cosmopolitan Hornwort: Phaeoceros carolinianus (Michx.) Prosk.



The morphological and anatomical characteristics of Phaeoceros carolinianus (Michx.) Prosk. were investigated. Samples were collected from Chiang Mai, Thailand, during September - October 2013. The gametophyte and the sporophyte samples including spores and pseudoelaters were examined under a light and scanning electron microscope. The gametophyte exhibits a single large chloroplast with a pyrenoid in the center, the absence of a schizogenous cavity, both smooth and tuberculate rhizoids along the median region of the ventral side and the presence of Nostoc colonies located on the ventral side of the thallus. The sporophyte consists of 4 - 5 assimilative layers and one layer of tetrads that surround the 16-celled columella (4´4 rows of cell). The crescent-shaped foot can usually be seen. The sporogenesis with successive division begins at the base and moves forwards to the tip in an acropetal direction. The spores are spinose on the distal surface while on the proximal face ornamentation performed slight variations with medium papillae over vermiculated triradiate faces.


Gametophyte, hornworts, Phaeoceros, sporophyte

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