Rubus inermis Pourret (1788: 326)

Ferrer-Gallego, P. Pablo & Beek, Abraham Van De, 2021, On Rubus ulmifolius (Rosaceae) and related taxa, Phytotaxa 523 (2), pp. 155-166 : 160-162

Rubus inermis Pourret (1788: 326)

Lectotype (designated by Van de Beek 1979: 206): Pourret 3168 ( MAF-POURR). Ind. Loc: near Barcelona. ( Fig. 6 )

Van de Beek (1979) argued that R. inermis Pourret (1788: 326) is identical with R. ulmifolius . Because this name is earlier than R. ulmifolius it would be the correct name of the species. Monasterio-Huelin & Weber (1996) doubted the identity of both and claimed that R. inermis might be a hybrid of R. ulmifolius . The lectotype of R. inermis Pourret , published in Van de Beek (1979: 206), Pourret 3168 (MAF-POURR), looks like a normal R. ulmifolius without prickles, but hybrids can sometimes be very similar. However, the type does not show reduced fertility. This is confirmed by two other specimens of Pourret which were found after the publication of the type.

Another specimen (probably a duplicate of the lectotype) was found at P (with barcode P02521232 , image available at http://mediaphoto.mnhn.fr/media/1441338624753ZJhEBLGDiQxlEGfy). It consists of two unarmed inflorescences, with leaves and flowers, and clearly has young fruits that are not defective. At the base the sheet is annotated with “ Rubus inermis ” by Pourret, and also contains a label annotated as “ Rubus inermis P. / Caule fruticoso sub-rotundo. / Folis ternatis subtus tomentosis / an Canadensis. [handwritten by Pourret] / Pourret scripsit. [handwritten by Spach] / à Barcelona [handwritten by Pourret]” .

The best specimen is preserved in the Salvador herbarium at BC (BC-Salvador 3833). It consists of both an inflorescence and a young primocane with leaves ( Fig. 4 ). It looks like a normal R. ulmifolius without prickles. The Salvador family was a lineage of apothecaries who settled in Barcelona from the early 17th to the mid-19th century. The Salvador herbarium is the oldest and best-documented pre-Linnaean one in Spain. Its labels bear pre-Linnaean names used in the works of Tournefort, Bauhin, Lobel, Dodoens, Magnol or Clusius, among others ( Ibáñez et al. 2006, 2008). Around 1782, the collection was revised for the first time by Pierre André Pourret (1754–1818), a French clergyman who lived in exile in Spain at Santiago de Compostela from 1789 until his death ( Timbal-Lagrave 1875, Colmeiro 1891). Pourret added the Linnaean names of the species to the labels of the collection ( Camarasa 1989, 2007) and, in some cases, took out duplicates for his own herbarium ( Bolòs 1946), now conserved in MAF as an independent historical collection ( Gutiérrez-Bustillo & Navarro Aranda 1989). Some specimens in MAF-POURRET coming from the Salvador herbarium are among the most interesting in this collection. They can be easily recognized through the word “Salv” on the label, indicating a new pre-Linnaean description and thus a new taxon proposed by Joan Salvador. Moreover, Pourret published some taxa in his Chloris Narbonensis ( Pourret 1788) as new species under the Linnaean system. Also, he sent some of these specimens to Lamarck in Paris and to Willdenow in Berlin and they are now preserved in the P and B-W herbaria ( Bonnet 1916).

All three samples of Pourret’s plant show an unarmed, but for the rest normal R. ulmifolius . Van de Beek (1979, 2016) thought it was collected in a natural habitat, because Pourret in his protologue does not refer to a garden. However, on the label of the specimen in the Salvador collection is written: ‘In hortis colitur’ (handwritten by Salvador). Salvador also wrote ‘Romaguera de St. Francesc.’ Because this sample is not different from the other ones, these too, may have been collected in gardens of monasteries. The so called St. Francis blackberry is often bred in Franciscan monastery gardens because of its unarmed character. This plant was already known to early authors such as Tournefort (1700) and Barrelier (1714) and validated on the level of a variety by Weston: R. fruticosus var. inermis Weston (1770: 258) . The lectotype of this name was designated by Van de Beek (2016) from a specimen preserved at P (Tournefort 6078, P-TRF) ( Fig. 3 ).

The name R. inermis was used once again by Willdenow (1809: 549). It is not based on a specimen of Pourret, but on another sample in B-W: BW09891010 (image available at https://herbarium.bgbm.org/object/BW09891010), from a plant in the hortus of Berlin, and so heterotypic with R. inermis Pourr. , and consequently as a later homonym illegitimate. Monasterio-Huelin & Weber (1996) identified it as R. ulmifolius var. anoplosthyrsus Sudre (1909: 70) so as conspecific with R. ulmifolius . Van de Beek & Widrlechner (2021) accepted the identification by Monasterio-Huelin and Weber [Lectotype: B(BW09891010) (selected by Monaterio-Huelin & Weber 1996: 316, pro holotype)]. However, the specimen is somewhat different from the samples of Pourret and Tournefort: it has usually 3-foliate leaves of which the lower ones are often abaxially greenish grey (not white), with a more irregular serrature with long mucrons, small (almost) sessile lateral leaflets, ovate central leaflets, and often stipules with a large base.

In the herbarium of Jussieu are three specimens of R. inermis . At one of the sheets (P-JUSS 14325) is a mixture of various species, partially with influence of R. caesius Linnaeus (1753: 493) . The specimens on the other two sheets are more useful. One (P-JUSS 14333) looks like the specimens of Pourret and Tournefort, the other one (P-JUSS 14326) is similar to Willdenow’s plant. The labels do not provide further information, so that their origin is unknown. Later collections from the hortus in Paris are similar to the Willdenow plant (‘Cult. Paris. 10 sept. 1905 ’, P02972716; Delacourt s.n., cult. Paris, 29.08.1901, P04173016; Delacourt s.n., cult. ormament, Paris, 07.1895, P04181928 and P04181929).

So it seems that the form of Pourret was bred in gardens in Spain, the form of Willdenow in Berlin, and both forms also bred in Paris. Crane & Darlington (1927) researched the genetics of some Rubus taxa. They also checked what they called R. ulmifolius var. inermis . Though the specimen that they published in their paper is poor it seems to be a R. inermis Pourr. , with the better developed higher leaf with stalked lateral leaflets, lateral leaflets of normal size and an obovate central leaflet. The chromosome number is 14, as with R. ulmifolius . Michal Sochor (Olomouc) was so kind to check a sample of the Willdenow form, which is cultivated in the Rubus garden in Veenendaal ( The Netherlands). This one is tetraploid.

In sum, as far as conclusions can be drawn from present information, it appears that R. inermis Pourret (= R. fruticosus var. inermis Weston ) is an unarmed form of the diploid R. ulmifolius , while R. inermis Willd. is another, tetraploid taxon. Its precise status must be subject of further research.

Thunberg (1813: 7) published once again a R. inermis . The lectotype of this name was designated by Van de Beek & Widrlechner (2021: 82) from a specimen kept at UPS (UPS-THUNB 12270) ( Fig. 5 ). This material is identical, though heterotypic, with R. inermis Pourret (1788: 326) .

Both Willdenow and Thunberg related their plants to North America, where R. inermis is not found ( Van de Beek & Widrlechner 2021). The confusion may be caused by a comparison with R. canadensis Linnaeus (1753: 494) , which was already made by Pourret on his label (‘an canadensis ’ – maybe canadensis ?). Linnaeus (1753: 494) mentions that species as unarmed and this may have caused the suggestion that unarmed blackberries come from America.

Figures

FIGURE 3. Lectotype of Rubus fruticosus var.inermis Weston (P, Tournefort 6078, P-TRF).Image courtesy of the herbariumP,reproduced with permission.

FIGURE 4. Specimen of Rubus inermis Pourret preserved in the Salvador herbarium at BC (BC-Salvador 3833). Image courtesy of the herbarium BC, reproduced with permission.

FIGURE 5. Lectotype of Rubus inermis Thunberg (UPS-THUNB 12270). Image courtesy of the herbarium UPS, reproduced with permission.

FIGURE 6. Lectotype of Rubus inermis Pourret (Pourret 3168, MAF-POURR). Image courtesy of the herbarium MAF, reproduced with permission.