Table 3.

Means from eight to 20 readings of the percentage weights of potassium from X-ray microanalysis. All the data are from fully expanded green capsules.

order	species	no. stomata	readings	potassium weights (g)
Sphagnales	Sphagnum subnitensa	c100	guard cells	1.14 ± 0.08
			epidermis	1.48 ± 0.06
			ratio of K guard cells to epidermal cells	0.77
			guard cell K relative to epidermis	lower
Polytrichales	Polytrichum juniperinum	80–120	guard cells	0.19 ± 0.05
			epidermis	0.39 ± 0.07
			sporophyte surfaceb	0–0.09
			ratio of K guard cells to epidermal cells	0.49
			guard cell K relative to epidermis	lower
Funariales	Funaria hygrometrica	160–220	guard cells	0.43 ± 0.09
			epidermis	0.56 ± 0.2
			ratio of K guard cells to epidermal cells	0.77
			guard cell K relative to epidermis	lower
	Physcomitrella patens	10–13	guard cells	1.42 ± 0.42
			epidermis	3.34 ± 0.67
			ratio of K guard cells to epidermal cells	0.43
			guard cell K relative to epidermis	lower
Pottiales	Tortula muralis	6–8	guard cells	0.5 ± 0.03
			epidermis	0.6 ± 0.03
			ratio of K guard cells to epidermal cells	0.83
			guard cell K relative to epidermis	lower
Bryales	Bryum radiculosum	80–120	guard cells	0.43 ± 0.06
			epidermis	0.94 ± 0.39
			ratio of K guard cells to epidermal cells	0.46
			guard cell K relative to epidermis	lower
	Philonotis fontana	>100	guard cells	1.7 ± 0.29
			epidermis	1.7 ± 0.09
			ratio of K guard cells to epidermal cells	1
			guard cell K relative to epidermis	same

^aFrom Duckett et al. [47].

^bControl.