Table 1.

Code and origin of parent plants used to obtain spores.

Species	Plant	Focus4	Locality	Habitat type	No. of ind.5
ASPS	AS11	F	Kuinderbos, Flevoland, The Netherlands, site 1	Soil, on trench slope	206
	AS22	F	Kuinderbos, Flevoland, The Netherlands, site 2	Soil, on trench slope	328
	AS33	F	Kuinderbos, Flevoland, The Netherlands, site 3	Soil, on trench slope	262
	RC	NF	Rue de Caster, Liège, Belgium	Calcareous soil	> 200
ASPT	AT1	F	Kuinderbos, Flevoland, The Netherlands, site 1	Soil, on trench slope	9
	AT2	F	Kuinderbos, Flevoland, The Netherlands, site 2	Soil, on trench slope	9
	Eck	F	Eckelrade, Limburg, The Netherlands	Old garden wall	> 50
	B	NF	Bromney Common, London, UK	Old church wall	> 100
POLS	PS1	F	Kuinderbos, Flevoland, The Netherlands, site 1	Soil, on trench slope	15
	PS2	F	Kuinderbos, Flevoland, The Netherlands, site 2	Soil, on trench slope	110
	BRS	F/NF	obtained from Henk Braam B.V., fern grower	unknown	?
POLA	PA1	F	Kuinderbos, Flevoland, The Netherlands, site 1	Soil, on trench slope	31
	PA2	F	Kuinderbos, Flevoland, The Netherlands, site 2	Soil, on trench slope	112
	PA3	F	Kuinderbos, Flevoland, The Netherlands, site 3	Soil, on trench slope	74
	SG	F	Schone Grub, Limburg, The Netherlands	Calcareous soil	10
	BRA	NF	obtained from Henk Braam B.V., fern grower	unknown	?

ASPS = Asplenium scolopendrium, ASPT = Asplenium trichomanes subsp. quadrivalens, POLS = Polystichum setiferum, POLA = Polystichum aculeatum

¹The same site was also sampled by Wubs et al. [30], but plants differ²Wubs et al. [30] used the same parent plant in their study, with code KB-4

³Wubs et al. [30] used the same parent plant in their study, with code KB-12

⁴ F: gametophytes used as focal individuals (see text); NF: gametophytes used as non-focal individuals on paired dishes (inbreeding level II)

⁵The number of individuals present at the site where the plant was collected