Table 1.

Distribution and percent polymorphic ISSR bands in Penstemon hybrid complex

Parameter	CE	CL	XP	SP	GR
Number of populations	16	5	2	9	7
Number of accessions	46	13	6	31	26
Total bands scored
across populations	184	140	108	164	149
Percent bands polymorphic
across all populations	95	89	72	90	88
Private bands	42	10	2	15	16
Marker bands	47	3	0	9	8

Private bands are restricted to a single taxon. Marker bands are those found in a relatively higher percentage of one taxon but in a few individuals and populations of other taxa in the hybrid complex (e.g. at least 25% of all populations or individuals in one taxon and only a few individuals in the other taxon). P. centranthifolius (CE) is in section Gentianoides, whereas P. clevelandii (CL), P. spectabilis (SP), and P. grinnellii (GR) are in section Spectabiles. P. × parishii (XP) is the F₁ hybrid between P. centranthifolius and P. spectabilis. The close relationship among the species in section Spectabiles accounts for the lower numbers of private and marker alleles compared to the more distantly related P. centranthifolius.