| Author | Murphy, R.J. |
| Year | 2016 |
| Title | Evening-primroses (Oenothera) of Britain and Ireland |
| ISBN | 978-0-90-115849-9 |
| Series | B.S.B.I. Handbook |
| Type | Book/Report |
| How Complete | All the British species and hybrids known at the time, including very rare casuals. |
| Source | B.S.B.I. Handbook, No. 16, 96pp, Botanical Society of Britain and Ireland (BSBI) |
| Illustrations | Colour photographs, line drawings |
| Review (by Malcolm Storey) | Evening primroses have unusual genetics with balanced lethal alleles which result in heterzygous populations breeding true and behaving as separate species. There are two competing approaches: the broad or American approach recognises broad species concepts whereas in Europe a narrower concept has gained favour with correspondingly more species. There are three keys: Key A is based on Stace 3 (2010) and uses a "broad" species concept (4 species). Key B follows the "narrow" species concept (18 species and subspecies). Key C covers just the recorded hybrids and their reciprocal crosses (6), although omits the triple hybrid. Use Key A first. If no perfect match if found try Key B. If again there is no match, look for a hybrid in Key C. |
| Examine |  with x8 or x10 hand lens ( Stereo Microscope is also useful) |
| Specimen Preparation | Fresh or pressed speciemens with all stages from buds to ripe capsules. |
