Charophyceae is a taxon of green algae whose exact rank is the matter of some current debate. Some botanists recommend expanding the existing plant kingdom to include charophyceans and chlorophytes[1] while others consider Charophyceae to be a class within either the divisionsChlorophyta, Streptophytina, or Streptophyta[2][3][4]. Other systematists classify Charophyceae as a class under division Charophyta, with Chlorophyta remaining a distinct division[5].
Regardless of the exact classification of charophyceans, the consensus among botanists is that they are the organisms most closely related to embryophytes (traditional plants)[1][6]. Many of the complex traits related to sexual reproduction, photosynthesis, and other defining characteristics of plants evolved first in charophyceans; analysis of cpDNA (chloroplastDNA), for instance, reveals that many characteristics of plant chloroplasts evolved first in the charophycean generaStaurastrum and Zygnema[1][7].
References
^ abc Campbell, N. A. & Reece, J. B. 2005. Biology, Seventh Edition. Benjamin Cummings, San Francisco.
^ McCourt, R. M., Chapman, R. L., Buchheim, M. & Mishler, B. D. “Green Plants”. Accessed 13 December 2007
^ Guiry, M.D. & Guiry, G.M. 2007. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. AlgaeBase.org; searched on 13 December 2007
