Pentagramma Pityrogramma triangularis Adiantaceae

Additional information on chemical variation within this species came from studies of exudate and internal (vacuolar) pigments based on broader collections of the fern (Star et al., 1975a, b). Exudate flavonoids, identified from specimens representing the range of the species, were identified as ceroptene [221], the C-methylflavonol pityrogrammin [222], and two derivatives of kaempferol, the 4 -methyl ether [223] and the 7,4 -dimethyl ether [224] (see Fig. 2.69 for stmctures 221-224). 

One final note on this topic involves an examination of diploid, triploid, and tetraploid plants for their leaf exudate hydrocarbons (Seigler et al., 1975). -Alkanes having odd numbered chains from to were recorded for almost all plants collected from several sites with much more limited distribution of hydrocarbons based on and C g. The hydrocarbon data do not assist in distinguishing groups within this species. 

Interested readers can find information on geographic variation in aboveground architecture and leaf characters of Encelia farinosa in response to temperature and available water in Housman et al. (2002), and a discussion of chemical variation and defense against predation in a report by Wisdom (1985). 

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