Pink-flowered fumitories
This post regards those species that feature flowers with corolla that is pink at the beginning of flowering, not those with a corolla that becomes pink to purple with age.
When I started identifying fumitories in iNat I noticed that in some cases there was some confusion in these pink-flowered species and it happened that in some geographical areas for them the identification as F. officinalis was suggested by the AI. Actually, F. officinalis in some areas seems rather rare while other species such as F. bastardii and F. muralis regard the vast majority of observations.
Here a key to distinguish these species
1 - Corolla shorter than 9 mm. Sepals lanceolate. Upper petal with almost almost flat margins at apex, broadly spathulate and often slightly emarginate. Fruit usually broader than long, broader in upper half, emarginate or truncate at apex, very rarely broadly rounded. Inflorescence rich with 10 to 80 flowers. Leaves laciniae comparatively much narrower: F. officinalis s.l.
1' - Corolla longer than (8-)9 mm. Sepals ovate to suborbicular. Upper petal with margins from slightly to strongly bent upwards at apex, never spathulate but subobtuse to subacute. Fruit slightly longer than broad, broader in the middle, rounded at apex. Inflorescence comparatively less rich with with 8 to 25 flowers. Leaves laciniae comparatively much broader: 2
2 - Inflorescence usually longer than peduncle (very rarely as long as or shorter), with 10-23(26) flowers. Corolla (8)9-11(12) mm long. Sepals ovate or elliptical or rarely suborbicular, 2,5-3,5 x 1,5-2,5(3?) mm, usually distinctly dentate at margin. Upper petal pink or dark purple at apex. Fruit strongly rugose when dried. Stigma?: F. bastardii
2' - Inflorescence usually longer than peduncle (rarely as long as or shorter?), with 8-20(25) flowers. Corolla 10-15 mm long. Sepals ovate or elliptical or rarely suborbicular, 3-5 x (1,5)2-2,5(3) mm, usually subentire or with soem teeth at base. Upper petal dark purple at apex. Fruit smooth or slightly rugulose when dried. Stigma with a distinctly visible central appendix that is longer than the two lateral ones: F. reuteri
2'' - Inflorescence usually shorter than or as long as peduncle (very rarely longer), with 8-15(20) flowers. Corolla (8)9-12(13) mm long. Sepals ovate or elliptical or rarely suborbicular, 2,5-5 x (1,5)2-2,5(3) mm, dentate or subentire at margin. Upper petal dark purple at apex. Fruit smooth or slightly rugulose when dried. Stigma with a barely visible central appendix that is shoter than the two lateral ones: F. muralis s.l.
- F. officinalis is easily identified, even without measuring corolla length, because the upper petal is flat and very broad apex. The inflorescence is always very rich in flowers. If fruits are available, they are extremely typical being rather broad (broader in upper third) with the apex usually emarginate or truncate.
- F. bastardii can often be easily identified when the upper petal is concolorous being pink and not purple at apex and when it has a relatively rich inflorescence. The observation of the dried fruit surface is easy with just a linen tester and can be decisive to exclude both F. muralis and F. reuteri.
- F. reuteri and F. muralis are often hard to distinguish also in consideration that, at least, F. muralis can rarely show an inflorescence longer than peduncle. A reliable identification should need the observation of the stigma with a microscope.
Anyway, the recommendations made in this previous post are still valid:
https://www.inaturalist.org/journal/blue_celery/31675-fumaria-what-to-photograph-for-the-identification
References:
Lidén, M. 1986. Synopsis of Fumarioideae (Papaveraceae) with a monograph of the tribe Fumarieae. Opera Botanica 88: 1-133.
Lidén, M. 1986b. Fumaria L. In S. Castroviejo & al. (eds.): Flora Iberica 1: 447-467.
http://www.floraiberica.es/floraiberica/texto/pdfs/01_038_13_Fumaria.pdf
Murphy, R.J. 2009. Fumitories of Britain and Ireland. Botanical Society of the British Isles.
