Santolina villosa Miller (1768

Ferrer-Gallego, P. Pablo, Sáez, Llorenç, Wajer, Jacek, Giacò, Antonio & Peruzzi, Lorenzo, 2021, Typification of the names Santolina ericoides and S. villosa (Asteraceae) revisited, Phytotaxa 509 (2), pp. 233-240 : 235-236

Santolina villosa Miller (1768 : Santolina No. 2)

Giacò et al. (2021) designated a neotype for this name, selecting a specimen kept at PAL (barcode PAL-Gr 064650). However, this designation should be superseded according to Art. 9.19 (a) of the ICN because at least one specimen that is part of the original material does exist. Given the above, a lectotype should be designated .

In accordance with the rules outlined by Miller in the Introduction to the eighth edition of the Gardeners Dictionary, the protologue of Santolina villosa Miller (1768 : Santolina No. 2) includes a Latin diagnosis “2. SANTOLINA (Villosa) pedunculis unifloris, calycibus globosis, foliis quadrisariàm dentatis tomentosis” and its English translation “ Lavender-cotton with one flower upon a foot-stalk, globular empalements, and woolly leaves which are indented four ways ”, followed by the synonym “ Santolina flore majore , foliis villosis & incanis. Tourn, Inst. 460” (this reference being to Tournefort 1719: 460) translated into English as “Lavender-cotton with a larger flower and hoary leaves”. The protologue is also accompanied by a more detailed description in the main article on the genus Santolina : “The second sort has a shrubby stalk with branches out like the former [i.e. No. 1 S. chamaecyparissus L.], but the plants seldom grow so tall. The branches are divided into a great number of stalks, which are short, hoary, and garnished very closely below with leaves shaped like thofe of the other sort, but are shorter, thicker, and whiter; the flowers are much larger, and the brims of the florets are more reflexed; they are of a deeper sulphur colour than the other, but appear at the same time”. Miller concludes his description by providing information about the origin of this species, which according to him “grows naturally in Spain ”.

No particular specimens or illustrations are cited in the protologue, so the lectotype has to be selected from any elements of the original material that were available to Miller before the eighth edition of the Gardeners Dictionary was published in 1768. Miller’s own personal herbarium, said to contain almost 10,000 specimens, was purchased by Sir Joseph Banks in 1774 and was later incorporated into the General Herbarium at BM (Britten 1913). Unfortunately, no specimen identifiable as S. villosa can now be found in Miller’s own collection at BM. There is also no material of S. villosa amongst the specimens of plants grown at the Chelsea Physic Garden (of which Miller was the director from 1722 to 1771) and sent to the Royal Society between 1722 and 1796 as part of an agreement between Sir Hans Sloane and the Worshipful Society of Apothecaries. This collection of nearly 4,000 specimens gathered by Miller’s assistants (not by Miller himself) was transferred to the British Museum in 1781 and integrated into the General Herbarium in the late 1880s ( Stearn 1972).

One specimen however, directly corresponding to Miller’s concept of Santolina villosa , still survives in the Sloane Herbarium (BM-SL) at the Natural History Museum in London ( Fig. 2 ). It forms part of a consignment of nearly 1,500 specimens of various plants grown by Miller at the Chelsea Physic Garden and presented to Sir Hans Sloane between 1727 and 1739 ( Wajer 2020). The specimen can be found on folio 65 in Volume No. 294 of Sloane’s Collection (H.S. 294 fol. 65), where it is mounted together with the specimen of S. chamaecyparissus (probably for comparison). It consists of a branch with leaves and capitula identified by Miller as “ Santolina flore majore foliis villosis & incanis Inst. R. H. 460 ”, which is the Tournefort’s name (1719: 460) cited in the protologue for S. villosa . It was indeed under this very name that Miller initially described this species in the first edition of the Gardeners Dictionary ( Miller 1731). Miller continued using Tournefort’s polynomial solely until the seventh edition of the Dictionary ( Miller 1756 –1759), when he added to it a new Latin diagnosis and a much longer English description, all reproduced verbatim in the eighth edition of the Dictionary in 1768, where the name S. villosa was validly published.

The specimen in the Sloane’s Herbarium is the only surviving element of the original material for S. villosa and it matches the current concept and use of Miller’s name ( Giacò et al. 2021), showing several of the diagnostic characters for this taxon (e.g. whitish or greyish tomentose leaves and stems and hairy involucral bracts) ( Fig. 3 ). According to Giacò et al. (in revision), this species shows two different cytotypes. Indeed , material from Southern Spain (Gor, Granada) is hexaploid (2 n = 6 x = 54), while material from Central and Central-Eastern Spain is tetraploid (2 n = 2 x = 36). At the present state of knowledge, there is no obvious morphological feature distinguishing these cytotypes, so that it is not possible to infer to which cytotype the lectotype may apply. However, more studies are needed to elucidate the systematic relationships between these two cytotypes .

Figures

FIGURE 2. Lectotype of Santolina villosa Miller (BM-SL: H.S. 294 fol. 65 – specimen on the left hand side of the folio). Photography by courtesy of Herbarium BM; reproduced with permission.

FIGURE 3. Detail of the bracts, leaves, and stem of the specimen of Santolina villosa Mill. preserved in the Sloane Herbarium (BM-SL: H.S. 294 fol. 65 [specimen on the left hand side of the folio]) at BM-SL. Photography by courtesy of Herbarium BM; reproduced with permission.