| Species | Geographic coordinates | ||||||
|---|---|---|---|---|---|---|---|
| Voucher (Herbarium) | Latitude | Longitude | Elevation (m) | State (Country) | County/unit | N | |
| Rhododendron groenlandicum (Oeder) Kron & Judd | Antieau 01‐29 (WTU)a | 47.40 | −121.92 | 228 | Washington (USA) | King | 1 |
| Rhododendron groenlandicum | Beaulieu s.n. (BUT)b | 61.17 | −113.68 | 158 | NW Territories (CAN) | Fort Smith | 24 |
| Rhododendron groenlandicum | LaBounty s.n. (BUT)b | 57.06 | −135.19 | 151 | Alaska (USA) | Sitka | 22 |
| Rhododendron groenlandicum | Mitchell 473 (BUT)b | 44.56 | −67.61 | 8 | Maine (USA) | Washington | 22 |
| Rhododendron columbianum (Piper) Harmaja | Arnot 73 (WTU)c | 48.52 | −120.67 | 1654 | Washington (USA) | Chelan | 1 |
| Rhododendron columbianum | Denton 4271 (WTU)c | 41.01 | −123.08 | 1584 | California (USA) | Trinity | 1 |
| Rhododendron columbianum | Denton 3144 (WTU)c | 42.04 | −123.02 | 938 | Oregon (USA) | Curry | 1 |
| Rhododendron columbianum | Smith 3172 (WTU)c | 45.63 | −115.68 | 1615 | Idaho (USA) | Valley | 1 |
| Rhododendron columbianum | Kruckeberg 6547 (WTU)c | 48.96 | −119.80 | 2134 | Washington (USA) | Okanogen | 1 |
| Rhododendron tomentosum Harmaja | Putnam 24 (WTU)c | 70.48 | −155.06 | 1 | Alaska (USA) | North Slope | 1 |
| Rhododendron tomentosum | LaBounty s.n. (WTU)c | 59.26 | −135.84 | 244 | Alaska (USA) | Haines | 1 |
| Rhododendron tomentosum | Gustafsen s.n. (WTU)c | 69.361 | −145.08 | 866 | Alaska (USA) | North Slope | 1 |
| Rhododendron diversipilosum (Nakai) Harmaja | Kihlman 20040770 (ARS)c | 43.35 | −142.91 | 837 | Hokkaido (Japan) | NA | 1 |
| Rhododendron hypoleucum (Kom.) Harmaja | Larsen 87/04 (ARS)c | — | — | — | — | NA | 1 |
| Rhododendron palustre (L.) Kron & Judd | Chase MWC869 (K)c | 50.14 | −86.30 | 1052 | Siberia (Russia) | Kurai | 1 |
| Rhododendron tolmachevii (Tolm.) Harmaja | Theqvist 20040806 (ARS)c | 53.56 | −127.41 | 365 | Amur (Russia) | NA | 1 |
— = horticulture specimen of uncertain provenance; N = number of individuals; NA = not available; ARS = American Rhododendron Society Rhododendron Species Botanical Garden, Federal Way, WA; BUT = Friesner Herbarium (Butler University); K = Royal Botanic Garden Kew Herbarium; WTU = Burke Museum (University of Washington).
a
Voucher for Illumina sequencing.
b
Voucher for marker development (separate collection effort).
c
Voucher for cross‐amplification.