Notes on Lactuca saligna in Iran

In the identification process of weed materials available in "IRAN" herbarium, a specimen belonging to the genus Lactuca (Asteraceae) had the following characteristics: Plant annual, many stemmed from base; stem erect-slightly procumbent, slender, glabrous, whitish and leafy. Basal leaves dried; stem leaves ca. 7 × 0.5 cm, glabrous, linear-lanceolate, entire at margin, sessile, auriculate, auricles small, forming a hastate leaf base. Inflorescence spike-like; heads in the axils of reduced leaves, shortly pedicelate, solitary or in clusters of 2-3; involucres narrow, ca. 12 mm long; florets turning purplish when dry. Achenes ca. 4 × 1 mm, light brown, flattened, inversely ovate, many-ribbed, in upper part provided with short hairs, with filiform 3-3.5 mm long beak; pappus white, deciduous (Fig. 1). The above-mentioned specimen was already identified as Lactuca saligna L. This species which is known as willow-leaf lettuce and narrow-leaved wild lettuce was described from Germany and is distributed in Europe, Mediterranean region, Caucasia and N. Africa. Lactuca saligna has reported in all Floras of western neighboring countries of Iran. In the Flora Iranica area, this species is reported only from Iraq (Rechinger 1977). Lactuca saligna has been reported by Parsa (1943) from four localities in Iran. Many of Parsa's specimens are found in Herbaria of Vienna (W), Berlin (B) & Kew (K), but as none of these specimens are listed in Flora Iranica (which was published 34 yrs after Parsa's Flore de lIran), it seems that Parsa's specimens did not exist at the mentioned herbaria. By visiting Herbarium of Pharmacy Faculty of Tehran University (THE), we could only find one specimen determined as L. saligna, mounted on two sheets with Nos: 10834 & 10835 (1169), both collected from Lowra, 2000 m, 20 Jun. 1955, M. Sotoodeh. More studies revealed that, the said specimen was Lactuca orientalis Boiss. (= Scariola orientalis (Boiss.) Sojak. In the Flora of former Soviet Union (Kirpichnikov 1964), L. altaica and L. saligna considered as distinct species, the proportion of achene's beak to achene's body is their only difference. But, only L. altaica is reported from Iran (Kurdestan), without citing any locality. It is noticeable that L. altaica is presently considered as a synonym of L. saligna, reported only from N. Iran, but without substantiating by a specimen citation (Heller & Heyn 1993). Checking different references shows that reporting of L. saligna from some parts of Iran was mostly on the basis of one specimen without citing the exact locality and there is no specimen of this species in any Iranian herbarium. Furthermore, none specimen of this species has been reported in Flora Iranica. The only specimen of this species which is presently available in "IRAN" herbarium (54460-IRAN) has been collected as a weed without a note on its collecting locality.