Ceratolejeunea cornuta (Lindenb.) Steph., 1895

Pócs, Tamás & Chantanaorrapint, Sahut, 2015, Ceratolejeunea tahitensis, a new synonym of C. cornuta (Lejeuneaceae, Marchantiophyta), Phytotaxa 207 (2), pp. 213-214 : 213-214

Ceratolejeunea cornuta (Lindenb.) Steph. in Engler, Pflanzenwelt Ost-Afrikas. Theil C: 65. 1895.

≡ Jungermannia cornuta Lindenb., Acta Nova Acad. Caes. Leop.-Carol. Suppl. 14: 23. 1829. Type:— Jamaica, on Grammitis serrulatus, Swartz s.n. (holotype: W)

= Ceratolejeunea calabariensis Steph. , Hedwigia 34: 234. 1895. Type:— NIGERIA. Niger-Gebiet: Neu Calabar, ad truncos, 8 October 1884, Mönkemeyer 5 (holotype G00045144, isotype JE!), synonymized by Pócs (2011: 133).

= Ceratolejeunea tahitensis Steph., Sp. Hepat. [Stephani] 5: 444. 1913. Type:—TAHITI. s.d., Nadeaud s.n. (lectotype G00069754 !, designated here); PHILIPPINES, Luzon, Prov. Tayabas [Quezon Province]: M. Binnang, August 1909, Robinson s.n. (syntype JE!) syn. nov .

For further synonyms, see Dauphin (2003) and Pócs (2011).

Ceratolejeunea cornuta is a very variable species, concerning both the length of perianth horns and its leaf morphology. The main features include 1) orbicular to reniform underleaves with cordate bases, 2) the lateral leaves bearing 1–2 isolated basal ocelli, 3) small leaf lobules about 1/6–1/5 as long as the leaf lobes, 4) large trigones of leaf cells, and 5) a perianth with four well-developed horns, often highly variable in length. Ceratolejeunea tahitensis falls very well within this variability.