Taxacom: The type of Cryptonemia J. Agardh (1842)

[Athanasios Athanasiadis]

Woelkerling et al. (2019a,b) treated *Cryptonemia lactuca *J. Agardh
(1842, *nom.
illeg*.) as the lectotype of this genus and a synonym of *Cryptonemia
palmetta* (S.G. Gmelin) Woelkerling et al. (l.c.) (= *Fucus palmetta* S.G.
Gmelin 1768, pl. 22 fig. 2, pl. 23), but they neither offered a convincing
nomenclatural analysis nor *new* evidence to support the proposed
synonymy (*Fucus
palmetta =* *Cryptonemia lactuca *= *Cryptonemia lomation*).

            Agardh (1842: 100-101) erected *Cryptonemia* for two species: '*Cr.
lactuca* *nob.* *Sph. lactuca Ag.' *and '*Cr. dichotoma'*, but the new
genus also included *Fucus palmetta* S.G. Gmelin and *Fucus lomation*
Bertoloni - two species names cited in the synonymy of *Sphaerococcus
lactuca *by C. Agardh (1822: 231) and included in the new genus as indirect
citations/references (Art.10.2 & Art.10.3). Montagne (1846: 109-110)
discussed only *Cryptonemia lactuca* without selecting a generitype.
Subsequently, Agardh (1851-1852: 224-228) divided *Cryptonemia* into the
subgenera *Cryptonemia *and* Acrodiscus*, maintaining in the autonym "*Cr.
lactuca"* for Atlantic thalli and *Cr. lomation* (Bertoloni) J. Agardh
(1851-1852: 227) for Mediterranean thalli (= *Cr. lactuca* J. Agardh 1842).
The name *Cryptonemia lactuca* was originally created as a new combination
(J. Agardh 1842), based upon *Sphaerococcus lactuca *C. Agardh (1822) and
is a superfluous (illeg.) epithet change of *Fucus palmetta* S.G. Gmelin
(1768) (Woelkerling et al. 2019a,b) - while C. Agardh (1822) was obliged to
change the epithet to avoid *Sphaerococcus palmetta* C. Agardh (1817), J.
Agardh (1842) had to re-use it.

            In *Species Algarum*, however, Agardh (1851-1852: 659)
excluded *Fucus
palmetta* S.G. Gmelin (= *Cr. lactuca* J. Agardh 1842) from
*Cryptonemia *referring
Gmelin's species as a putative synonym of *Nitophyllum laceratum* (S.G.
Gmelin) Greville. Therefore, the accepted "*Cr. lactuca"* by J. Agardh
(1851-1852: 227) must be treated as a new/later (illeg.) homonym (Art.
48.1). Because *Cryptonemia dichotoma* was simultaneously assigned to the
subgenus *Acrodiscus* J. Agardh (1851: 225), *Cryptonemia (Fucus) lomation *is
the only species name maintained from the protologue of *Cryptonemia* (J.
Agardh 1842)*,* and hence it is implicitly the unequivocal lectotype of the
(sub)genus *Cryptonemia* (Art.7.6).

            The crucial points that reject Woelkerling et al.'s (2019b)
interpretation lie in Art.37.5 that treats Agardh's (1851-1852) *Species
Algarum* as a single publication (where *Fucus palmetta* S.G. Gmelin,
including Gmelin's illustrations of this species, were excluded from
*Cryptonemia*), and in Art.10.2-10.3 that accept an indirect reference to a
species as part of the protologue of a genus.

            Woelkerling et al. (2019a) further considered *Fucus palmetta*
S.G. Gmelin to be referable to *Cryptonemia lomation,* but they did not
offer new evidence and this synonymy remains to be investigated using
modern techniques (e.g. image analysis of Gmelin?s illustrations).

            References to the above citations can be found in the 5th
addendum [Botanica Marina 65(2): 141-151. 2022] and in Phycologia Europaea
Rhodophyta (Athanasiadis 2016).



A. Athanasiadis

G?teborg