Rosa agrestis Savi, syn.: Rosa arvatica Baker, Rosa pubescens (Rapin) Klášt. [non Sleich. 1815], Rosa albiflora Opiz, Rosa rubiginosa subsp. agrestis (Savi) Hook., Rosa sepium Thuill and almost 40 other names
Family: Rosaceae Bercht. et J. Presl
EN: Small-leaved Sweet Briar, Field Briar, Fieldbriar, DE: Acker-Rose, Feldrose, Hoher Hagedorn
Slo.: poljski šipek
Dat.: May 24. 2022
Lat.: 44.81469 Long.: 14.39921
Code: Bot_1470/2022_DSC00106
Habitat: garrigue, during rainy periods muddy ground; open, sunny, calcareous, skeletal ground, mostly dry; flat terrain; elevation 195 m (640 feet); average precipitations ~ 1.000 mm/year, average temperature 12-14 deg C, Sub-Mediterranean phytogeographical region.
Substratum: soil.
Place: Adriatic Sea, island Cres, next to the road toward village Grmov, west of it; about 1.9 km southeast of the village, Kvarner archipelago, Rijeka region, Croatia EC.
Comment (pertains to pictures in the Flickr album Rosa agrestis): Rosa agrestis is a beautiful plant as almost all briar-roses. Its rather small, dark green and shiny leaflets and hundreds of white flowers (rarely with pink tint) make this, up to two meters high (rarely more and many times less), bushes wonderful when blooming as well as when in fruit. The plant is a Sub-Mediterranean – Sub-Atlantic floral element loving warm climate. Hence it is quite a rare find in Central and Northern Europe. It is very similar to frequently cultivated sweet briar (Rosa rubiginosa), but has smaller leaves, white instead of pink flowers and less distinctive odor. Its flowers are usually solitary, sometimes two or three together, in contrast to Rosa rubiginosa where the flower clusters may have up to seven flowers.
Briar rose species are notoriously variable, form hybrids and intermediate forms often and are numerous. Their botanical determination is by no means easy. One has to observe several parts of the plant: details of the flowers; shape and color of hips and leaves; young and old branches and their bark, position, shape and numerousness of prickles; hairiness of all parts of the plant, habitus (and taste of rose hip jam, ;-)) if one wants to be sure in his determination. Usually one needs also some luck to find a truly characteristic form of a given species and not an intermediate form or hybrid. In the latter case, one almost needs to be a 'genus expert' to find out what he has actually found.
Rosa agrestis should have: leaves pinnate with normally seven leaflets (Fig. 10), glandular rachis without (even small) prickles (Fig. 10), deep green, shiny and glabrous upper side of the leaflets (Fig. 10), glandulous lower side of the leaflets (Fig. 9 lower left), leaflets' edge serrate and glandular (Fig. 5), styles separate, not fuzzed into a column and (nearly) glabrous (Fig. 2) pear shaped, scarlet colored hips, which are often retained on the plant for a long time; large, reddish sickle shaped prickles turned downwards on young branches (Fig. 5), gray older branches with gray, not dense prickles (Fig. 7); no bristles, glabrous fruit and flower stalks (Fig. 9); quite persistent (some sources say: soon falling off ?) and pinnately divided, long (Fig. 9) and recurved sepals after the petals fall off.
Latin (agrestis), German (Acker), English (field) as well as Slovenian (poljski) species name insinuates it grows in fields. However, these names are all misleading. The plant does not appear on agricultural land.
Ref.:
(1) M.A. Fischer, W. Adler, K. Oswald, Exkursionsflora für Österreich, Liechtenstein und Südtirol, LO Landesmuseen, Linz, Austria (2005), p 524.
(2) A. Martinči et all., Mala Flora Slovenije (Flora of Slovenia - Key) (in Slovenian), Tehnična Založba Slovenije (2007), p 275.
(3) W.K. Rottensteiner, Exkursionsflora für Istrien, Verlag des Naturwissenschaftlichen Vereins Kärten (2014), p 827.
(4) T. Nikolić, Flora Croatica, Vaskularna flora Republike Hrvatske, Vol. 3. Alfa d.d.. Zagreb (2020) p 516,
(5) D. Aeschimann, K. Lauber, D.M. Moser, J.P. Theurillat, Flora Alpina, Vol. 1., Haupt (2004), p 752.
(6) K. Lauber and G. Wagner, Flora Helvetica, 5. Auflage, Haupt (2012), p 230.
