The morphology of filaments have both been reported to be ‘Nostoc’ like and ‘Anabaena’
like in the corraloid roots of Cycas. Molecular evidence has given indications of proximity to
Nostoc but these have not been very exhaustive studies.
What I feel personally (from my experiences as a taxonomist and a Professor who
regularly conducts practical sessions on both Corraloid Root and Azolla fronds) is as
follows:
Fig. 26.22 The difference between coralloid roots and more typical plant roots of cycad. This
montage shows the difference between coralloid roots, which are shown as a cluster in the upper left
of the cycad root zone, and the cycads more typical plant roots. These images are of Zamia
integrifolia and used with permission of their author, Jennifer Possley of the Fairchild Tropical
Botanic Garden, Coral Gables, Florida
572
C. J. Hurst
like in the corraloid roots of Cycas. Molecular evidence has given indications of proximity to
Nostoc but these have not been very exhaustive studies.
What I feel personally (from my experiences as a taxonomist and a Professor who
regularly conducts practical sessions on both Corraloid Root and Azolla fronds) is as
follows:
Fig. 26.22 The difference between coralloid roots and more typical plant roots of cycad. This
montage shows the difference between coralloid roots, which are shown as a cluster in the upper left
of the cycad root zone, and the cycads more typical plant roots. These images are of Zamia
integrifolia and used with permission of their author, Jennifer Possley of the Fairchild Tropical
Botanic Garden, Coral Gables, Florida
572
C. J. Hurst