(1577) Proposal to conserve the name Lithophyllum laeve Stromfelt against L. laeve Kutzing (Corallinales, Rhodophyta) with a conserved type

Leptophytum Adey (in Hydrobiologia 28: 323. 1966) was originally established to accommodate two widely distributed North Atlantic-Arctic species; viz. its type Leptophytum laeve (Stromfelt) Adey and Leptophytum foecundum (Kjellman) Adey. Subsequent studies have added to the genus a total of 15 species from temperate regions in both the Southern and Northern Hemispheres (Adey in Kgl. Norske Vidensk. Selsk. Skr. 1: 1-46. 1970; Zaneveld & Sanford in Blumea 26: 205-231. 1980; Steneck & Paine in Phycologia 25: 221-240. 1986; Chamberlain in Br. Phycol J. 25: 179-199. 1990; Chamberlain & Keats in Phycologia 33: 111-133. 1994). Woelkerling (The Coralline Red Algae: 217. 1988) treated Leptophytum as being of uncertain status because the whereabouts of the type material of Leptophytum laeve (= Lithophyllum laeve Stromfelt) was unknown. Dilwel & Wegeberg (in Phycologia 35: 470-483. 1996) reported the discovery by W. J. Woelkerling of the holotype of Stromfelt's Lithophyllum laeve in the Swedish Museum of Natural History in Stockholm (S), and after a study concluded that this element along with the original description of Str6mfelt (l.c.) were inadequate to define the identity of the species. Therefore, these authors selected an epitype from new material collected at the type locality Eyrarbakki (South Iceland). Unfortunately, the epitype selected and described by Diiwel & Wegeberg shows key characteristics of the lectotype of Phymatolithon lenormandii (Areschoug) Adey, rendering Leptophytum laeve and Leptophytum junior synonyms of Phymatolithon lenormandii and Phymatolithon Foslie, respectively. We have recently re-examined the holotype of Lithophyllum laeve Str6mfelt and shown that this element is in agreement with the protologue, matching not the selected epitype but all later descriptions of Leptophytum laeve as circumscribed in the literature of the 20th century (Adey & al. in Eur. J. Phycol. 36: 191-203. 2001) (see Table 1). A distinctive statement in the protologue, that the sporangia of Lithophyllum laeve Str6mfelt were twice as big as those of Phymatolithon lenormandii, is a characteristic definitively present in the holotype and clearly distinguishes these two species. Multiporate conceptacle roofs are also present in the holotype, and these numerically fall in the middle of the extensively described size and sporangial number (pore) range for Leptophytum laeve, at roughly twice the dimensions and pores of Phymatolithon lenormandii, and well beyond the maximum size range known for the latter species. Additionally, pore cells of multiporate conceptacles of the holotype are specialized and in agreement with those described for this species and not for Phymatolithon lenormandii (Adey & al. l.c.). The epitypification of Str6mfelt's Lithophyllum laeve by Dtiwel & Wegeberg has resulted in this name being presently typified by two heterogeneous elements, i.e., the holotype and the epitype, each apparently belonging to a different species and genus. Only the holotype is in agreement with the protologue, and since only this element provides key characteristics that unequivocally refer to our understanding of Lithophyllum laeve Stromfelt, the selected epitype by Diiwel & Wegeberg is both unwarranted and in serious conflict with the protologue. Nevertheless, the epitype cannot just be rejected, as