John L. Maron, Montserrat Vilà, Riccardo Bommarco, Sarah Elmendorf, and Paul Beardsley. 2004. Rapid evolution of an invasive plant. Ecological Monographs 74:261–280.

Appendix A. Locations of seed source populations.

Location	Collection site	Range	Latitude/ Longitude	Pop. number	Garden site
Germany	Hamborg	Native	53.55/10.58	18	WA, SP, CA, SE
The Netherlands	DeSteeg	Native	52.00/6.05	17	WA, SP
England	Silwood Park	Native	51.40/-0.66	16	WA, SP
Germany	Bonn	Native	50.73/7.1	15	WA, CA
Czech Republic	Prague	Native	50.08/14.46	14	WA, SP, CA, SE
France	Neuves Maisons	Native	48.60/4.03	13	WA, SP
Switzerland	Arlesheim	Native	47.48/7.61	12	WA, SP, CA, SE
Switzerland	Adliswil	Native	47.30/8.56	11	WA, SP, CA, SE
France	Pontailler-sur-Saône	Native	47.30/5.41	10	WA, SP, CA, SE
Italy	Bolzano	Native	46.51/12.15	9	WA, SP
Italy	Badia Polesine	Native	45.08/11.48	8	WA, SP
France	Clapier	Native	44.10/7.41	7	WA, SP, CA, SE
France	Assas	Native	43.70/3.88	6	WA, SP, CA, SE
Kyrgyzstan	Suu Ravine	Native	42.65/74.51	5	WA, SP
France	Cerbčre	Native	42.45/3.16	4	WA, SP, CA
Spain	Centellas	Native	41.80/2.22	3	WA, SP, CA, SE
Spain	Granera	Native	41.73/2.06	2	WA, SP, CA, SE
Spain	La Selva del Mar	Native	41.21/1.13	1	WA, SP, CA, SE
Montana	Ravalli	Introduced	47.30/113.96	18	WA, SP
Washington	Mima Mounds	Introduced	46.63/122.95	17	WA, SP, CA, SE
Oregon	Corvallis	Introduced	44.61/123.20	16	WA, SP, CA, SE
Oregon	Winchester	Introduced	43.26/123.36	15	WA, SP
Oregon	Sunny Valley	Introduced	42.70/122.88	14	WA, SP, CA, SE
Oregon	Gold Hill	Introduced	42.45/123.66	13	WA, SP
Oregon	Ashland	Introduced	42.20/122.71	12	WA, SP
California	Gasquet	Introduced	41.85/122.63	11	WA, CA, SE
California	Weed 1	Introduced	41.43/122.25	10	WA, SP
California	Weed 2	Introduced	41.33/122.38	9	WA, SP, CA
California	Mt. Shasta	Introduced	41.30/122.25	8	WA, SP
California	Eel River	Introduced	40.83/124.10	7	WA, CA, SE
California	Holiday	Introduced	40.62/122.30	6	WA, SP, CA
California	Covelo	Introduced	39.88/123.25	5	WA, SP, CA, SE
California	Sierra Field Station	Introduced	39.25/121.60	4	WA, SP, CA, SE
California	Meadow Vista	Introduced	39.00/121.08	3	WA, SP, CA, SE
California	Bass Lake	Introduced	38.66/119.50	2	WA, SP, CA, SE
California	Cazadero	Introduced	38.55/123.13	1	WA, SP, CA
Michigan	Iron Mountain	Introduced†	45.83/88.08	14	WA, SP, CA, SE
Michigan	Carney	Introduced†	45.60/87.03	13	WA, SP, CA, SE
Wisconsin	Wausaukee	Introduced†	45.45/87.63	12	WA, SP, CA, SE
Michigan	Menominee	Introduced†	45.21/87.75	11	WA, SP, CA, SE
Ontario , Canada	Rideau River	Introduced†	45.00/75.62	10	WA, SP, CA
Minnesota	Afton	Introduced†	44.90/93.06	9	WA, SP
Wisconsin	Gillett	Introduced†	44.84/88.61	8	WA, SP, CA, SE
Michigan	Kewaunee	Introduced†	44. 61/88.11	7	WA, SP, CA, SE
Wisconsin	Point Beach	Introduced†	44.26/87.56	6	WA, SP, CA, SE
Wisconsin	Green Lake	Introduced†	43.85/89.30	5	WA, SP, CA, SE
Michigan	Radrick	Introduced†	42.50/83.71	4	WA, SP
Michigan	ESGR	Introduced†	42.50/83.70	3	WA, SP, CA, SE
Wisconsin	Tecumseh	Introduced†	42.00/89.66	2	WA
Illinois	Tuscola	Introduced†	39.80/88.28	1	WA, SP

   Notes: Location refers to country (for native European populations) or state/province (for introduced North American populations) of origin. “Pop. number” is a reference number, used in Fig. 1, to indicate which population a given individual comes from. WA = Washington , CA = California , SE = Sweden , and SP = Spain.  All populations occurred below 1000 m and were separated from each other by at least 20 km. European collection sites average 3.9–16.8 cm of rainfall during May–August, the peak growing season for St. John’s Wort. For the same period, average rainfall ranges from 0.98–4.46 cm and 7.4–10.3 cm for western and central North American collection sites, respectively.

¹Introduced populations never exposed to biological control.