Table 1.
Ingroup species included in the current study for ITS2 and plastid locus sequencing (Table 2)
| Section | Series | Species | Ploidy (x = 17) | Distribution | Accessions |
|---|---|---|---|---|---|
| Brevispinae Beadle ex C.K.Schneid. | Brevispinae (Beadle) Rehder | C. brachyacantha Sarg. & Engelm. | 2x | Regional (LA, TX) | 3 |
| Coccineae Loudon | Crus-galli (Loud.) Rehder | C. crus-galli L. | 2x | E North America | 1 |
| Chrysocarpeae J.B. Phipps | C. chrysocarpa Ashe | 4x | N America | 2 | |
| Macracanthae (Loud.) Rehder | C. macracantha Lodd. ex Loud. | 4x | N America | 3 | |
| Punctatae (Loud.) Rehder | C. punctata Jacq. | 2x | E North America | 3 | |
| Triflorae (Beadle) Rehder | C. triflora Chapm. | 4x | SE USA | 1 | |
| Crataegus | Crataegus | C. monogyna Jacq. | 2x | W Eurasia | 4 |
| Pentagynae (C.K. Schneid.) Russanov | C. pentagyna Waldst. & Kit. | 2x | W Eurasia | 1 | |
| Pinnatafidae (Zabel ex C.K. Schneider) Rehder | C. pinnatifida Bunge | 2x | E Asia (China, Korea) | 3 | |
| Douglasia Loud. | Cerrones J.B.Phipps | C. erythropoda Ashe | 4x | Regional (CO, NM; SK?) | 2 |
| C. rivularis Nutt. | 4x | Regional (CO, ID, UT, WY) | 5 | ||
| C. saligna Greene | 2x | Regional (CO, UT) | 3 | ||
| Douglasianae (Loud.) Poletiko | C. castlegarensis J.B. Phipps & O'Kennon | 4x | Regional (Pacific Northwest) | 4 | |
| C. douglasii Lindl. | 4x | Pacific Northwest, Great Lakes basin | 13 | ||
| 5x | Local (BC) | 1 | |||
| C. gaylussacia A. Heller | 3x | Marin and Sonoma Counties, CA | 5 | ||
| C. okennonii J.B. Phipps | 4x | Regional (BC, ID, MT, WA) | 2 | ||
| C. shuswapensis J.B. Phipps & O'Kennon | 4x | Local (BC, MT) | 1 | ||
| C. suksdorfii (Sarg.) Kruschke | 2x | W of Cascades (CA, OR, WA) | 14 | ||
| 3x | Regional (Pacific Northwest) | 5 | |||
| 4x | Local (ID, MT) | 1 | |||
| 5x | Local (BC) | 2 | |||
| Montaninsulae J.B. Phipps & O'Kennon | C. rivuloadamensis J.B. Phipps & O'Kennon | 4x | Local (Cypress Hills) | 1 | |
| C. rivulopugnensis J.B. Phipps & O'Kennon | 4x | Local (Cypress Hills) | 1 | ||
| Purpureofructi J.B. Phipps & O'Kennon | C. aquacervensis J.B. Phipps & O'Kennon | 4x | Local (Cypress Hills) | 1 | |
| C. atrovirens J.B. Phipps & O'Kennon | 4x | Local (BC) | 1 | ||
| C. cupressocollina J.B. Phipps & O'Kennon | 4x | Local (Cypress Hills) | 1 | ||
| C. enderbyensis J.B. Phipps & O'Kennon | 4x | Local (BC) | 2 | ||
| C. okanaganensis J.B. Phipps & O'Kennon | 4x | Regional (BC, ID, WA) | 1 | ||
| C. orbicularis J.B. Phipps & O'Kennon | 4x | Local (BC) | 1 | ||
| C. phippsi O'Kennon | 4x | Regional (BC, MT, WA) | 1 | ||
| Mespilus (L.) T.A. Dickinson & E.Y.Y. Lo | C. germanica (L.) Koch | 2x | W Eurasia | 2 | |
| Sanguineae Zebel ex Schneid. | Nigrae (Loudon) Russanov | C. kansuensis E.H.Wilson | 4x | E Asia (China) | 1 |
| C. maximowiczii C.K.Schneid. | 2x | E Asia (China, Japan, Korea, Mongolia, Russia) | 2 | ||
| C. nigra Waldst. & Kit. | 2x | Central Europe | 1 | ||
| Sanguineae (Zebel ex Rehder) C.K. Schneid. | C. wilsonii Sarg. | 2x | E Asia (China) | 1 | |
| Hybrid | C. × cogswellii K.I.Chr. & T.A.Dickinson | 2x | Local (OR) | 2 | |
| Hybrid | C. × ninae-celottiae K.I.Chr. & T.A.Dickinson | 2x | Local (ON) | 2 | |
The infrageneric classification follows Phipps et al. (1990), Phipps and O'Kennon (1998, 2007) and Lo et al. (2007); also shown are ploidy level (Talent and Dickinson, 2005; Lo et al., 2007, 2010; J. Coughlan and N. Talent unpubl. data), geographical distribution [Christensen, 1992; Gu and Spongberg, 2003 (online version); Phipps et al., 1990; and specimens in TRT, including the J. B. Phipps Hawthorn Research Collection], and the number of individuals studied per species (see Supplementary Data Table S1 for voucher information and outgroup taxa).
Crataegus kansuensis and two C. douglasii accessions sampled from Montana (JC281 and JC296; Table S1) were not amplified for the plastid markers. Crataegus triflora was not amplified for ITS2.