Juno tarhunensis (Borzì & Mattei) M.B.Crespo, Mart. 2018

Crespo, Manuel B., Martínez-Azorín, Mario & Mavrodiev, Evgeny V., 2018, Notes on taxonomy and nomenclature of juno irises (Juno, Iridaceae), Phytotaxa 376 (5), pp. 185-200 : 192-194

Juno tarhunensis (Borzì & Mattei) M.B.Crespo, Mart. -Azorín & Mavrodiev comb. nov.

≡ Thelysia tarhunensis Borzì & Mattei (1913: 240) , basionym ≡ I. planifolia var. tarhunensis (Borzì & Mattei) Maire & Weiller in Maire (1959: 155) ≡ I. tarhunensis (Borzì & Mattei) Pampanini (1914: 59) ≡ I. scorpioides var. tarhunensis (Borzì & Mattei) Pampanini (1914: 59) .

Neotype (designated here):— LIBYA. Tripolitania : “ Plantae Tripolitanae a R. Pampanini anno 1913 lectae, nº 708 Iris planifolia (Mill.) Fiori. Tarhuna, Ain Scersciara [Tarhūnah, Ayn ash Sharshārah] [32°28’03.8’’ N, 13°37’ 12.70’’ E], 14 March 1913, R. Pampanini 708 ( FI052410 [digital image!]). Fig. 3 .

Observations:—Populations belonging to the Juno planifolia group, occurring in the surroundings of Tarhuna in northwestern Lybia, were first described at the species rank as Thelysia tarhunensis by Borzì & Mattei (1913), and later transferred to Iris by Pampanini (1914). It is worth mentioning that the fourth issue of Bollettino del Regio Orto Botanico e Giardino Coloniale di Palermo vol. 11, where Thelysia tarhunensis was published, apparently corresponds to “Ottobre− Dicembre 1912 ”; but the original material of the species was gathered in “ Tripol. Tarhuna (CROCIVERA, Gennajo 1913, fl.)” like other plants cited in the same paper which were also collected by Crocivera, a fact suggesting that Thelysia tarhunensis was effectively published about the midst of 1913. Furthermore, this name was also published in a reprint of Borzì & Mattei’s paper in Bullettino de la Società Botanica Italiana (issues 7–8, October–November 1913), as part of an “Extraordinary reunion of the Botanical Society of Italy hold in Siena” on 23 September 1913, which was probably released in December 1913. However, according to the citation of the protologue by Pampanini (1914: 59), Thelysia tarhunensis should have been first published in Bollettino del Regio Orto Botanico e Giardino Coloniale di Palermo.

Maire & Weiller (in Maire 1959) regarded Thelysia tarhunensis as a mere variety in Iris planifolia . Both taxa were said to differ by some characters of cataphylls, leaves and flowers (cfr. Borzì 1915). Nonetheless, among all features cited by the latter author, the leaves with a prominent cartilaginous-ciliate whitish margin and longitudinally silverveined beneath, the smaller flowers with falls trullate, ± uniformly deep-violet with an orange-coloured prominent central ridge, the standards suberect, narrowly spathulate, entire, acute, whitish to pale bluish (discoloured with regard to falls), and finally the crests of the stylar laminae narrowly triangular and acute-cuspidate, are never found in the western and central Mediterranean populations of J. planifolia and hence they reveal as diagnostic for the Libyan plants (see the illustration in Labani & El-Gadi 1980: 10 fig. 5). Other features typical in J. tarhunensis are the dwarf size; bulbs narrow and long, tapering into a long neck covered with dark-brownish spongy cataphylls; leaves often narrower and strongly recurved to coiled, longitudinally folded; flowers always small, usually darker violet coloured. These morphological divergences with regard to J. planifolia are strong enough to accept J. tarhunensis as a proper species, and not as a simple geographic or ecological variant of drier soils or arid climate. It is currently known from the littoral areas of Libya, from Benghazi to Tripoli (cfr. Labani & El-Gadi 1980: 11) it being the easternmost species of the J. planifolia group in North Africa. Some of the cited vegetative characters are also present in populations of J. planifolia growing in arid and semiarid areas of central Algeria and Tunisia, sometimes regarded as “ Iris planifolia var. micrantha (Batt.) Batt. ex Maire ”, and they can be considered as an adaptation to aridity (cfr. Mattei 1915). Further chromosome counts in all those North African populations will allow clarification of their taxonomical relationships. The original material of Thelysia tarhunensis is apparently lost, currently not extant in the Italian herbaria FI, FT, MS, PAD, PAL, PORUN and RO. Therefore, we here designate as neotype of T. tarhunensis the voucher FI052410 ( Fig. 3 ) collected in Tarhuna, Ain Scersciara [Tarhūnah, Ayn ash Sharshārah] by Pampanini, which matches the original concept of the species and was collected at the type locality. Although the neotype bears only withered flowers, the principal character cited in the protologue can be easily observed. We have also studied flowering and fruiting material of T. tarhunensis from Tripolitania (Ghiran, in lapidicinis antiquis ad occidentem urbis Tripolis, 4 & 10 April 1886, A. Letourneux, P02164980 [digital image!]; Tarhuna, Caser Tarhuna, 27 February 1913, R. Pampanini 366, FI052409 [digital image!]) and Cyrenaica (Benghasi, 18 December 1882, G. Ruhmer 327, P02164966 [digital image!]), fitting well the protologue, but either lacking some of the diagnostic characters or being more poorly preserved than the selected neotype.

Figures

FIGURE 3. Neotype of Thelysia tarhunensis Borzì & Mattei (FI052410). Reproduced with permission (Museo di Storia Naturale, Firenze, Italy).