Parallel Ecological Speciation in Plants?

Table 1

Candidate examples of parallel ecological speciation in plants showing the strength of evidence for each case. The details of each example can be found in Appendix A. The strength of evidence for each case was coded as follows: ***: strong direct evidence, **: weak direct evidence, *: indirect evidence, —: no evidence, †: evidence against, and NA: no data.

Species	Min. number of origins	Independence	Isolation	Compatibility	Selection	Major parallel trait(s)	References
Alopecurus myosuroides ^LX	Many	**	NA	NA	***	Herbicide tolerance	[45–51]
Agrostis capillaries ^LX	Many	*	*	*	**	Edaphic tolerance	[52–54]
Agrostis stolonifera ^LX	NA	NA	*	*	**	Edaphic tolerance	[55–57]
Agrostis tenuis ^L	NA	*	**	NA	**	Edaphic tolerance	[58, 59]
Armeria maritima ^LX	NA	***	†	*	*	Edaphic tolerance	[60–63]
Chaenactis spp. ^LX	2	***	†	**	*	Flower colour	[64, 65]
Cerastium alpinum	2	**	*	NA	***	Edaphic tolerance	[66]
Chenopodium album ^LX	NA	*	NA	NA	*	Herbicide Tolerance	[67–70]
Crepis tectorum ^LX	2	**	NA	NA	**	Leaf morphology	[71, 72]
Deschampsia caespitosa ^L	2	**	*	*	*	Edaphic tolerance	[73, 74]
Eucalyptus globulus	3	***	**	*	*	Dwarfed morphology	[75]
Geonoma macrostachys	3	**	**	*	*	Habitat type; reproductive strategy	[76–78]
Hemerocallis citrina var. vespertina	3	**	*	*	NA	Nocturnal flowering	[79]
Hieracium umbellatum ^LX	NA	*	*	*	*	Habitat type (dunes)	[80]
Lasthenia californica	2	***	**	**	**	Edaphic tolerance	[81–87]
Microseris lanceolata ^L	2	***	*	**	*	Habitat type (elevation)	[88–90]
Petunia axillaris	6	**	***	*	—	Flower colour	[91, 92]
Plantago maritima ^LX	2	*	NA	NA	NA	Spike morphology	[93]
Poa annua ^LX	NA	*	—	*	*	Herbicide tolerance	[94, 95]
Schizanthus grahamii	2	**	**	NA	*	Pollination syndrome, self-compatibility	[96]
Silene dioica ^LX	NA	**	NA	NA	—	Edaphic tolerance	[97, 98]
Silene vulgaris ^LX	2	*	*	NA	***	Edaphic tolerance	[99–102]
Streptanthus glandulosus	Many	**	*	*	**	Edaphic tolerance	[103–107]

^L: Levin example.
^X: Example that would not have been included in this table had they not been reviewed in Levin [12].