Hysterionica resinosa (Spreng.) P.L.R.Moraes, 2020

Moraes, Pedro Luís Rodrigues De, 2020, Nomenclatural notes on the taxonomic identity of Sprengel’s Erigeron dubius, E. montevidensis, E. resinosus and E. filiformis (Asteraceae), Phytotaxa 438 (2), pp. 95-106 : 99-100

Hysterionica resinosa (Spreng.) P.L.R.Moraes , comb. nov.

Basionym:— Erigeron resinosus Sprengel (1826: 519) ≡ Polyactis sprengelii Schlechtendal (1835: 475) , nom. illeg. superfl. ≡ Polyactidium sprengelii Candolle (1838: 275) , nom. illeg. superfl. Protolog:—“ Ad fl. magnum Amer. austr. (Rio grande.) Sello”. Type:— BRAZIL. “Rio Grande”, s.d., F. Sellow s.n. (lectotype designated here: P barcode P02484186, ex Herb. Sprengel 1102).

Synonyms:— Erigeron dubius Sprengel (1826: 519) . Protolog:—“ Ad fl. magnum Amer. austr. (Rio grande.) Sello”. Type:— BRAZIL. “Rio Grande”, s.d., F. Sellow s.n. (lectotype designated here: P barcode P02484185, ex Herb. Sprengel 1100).

Diplopappus villosus Hooker & Arnott (1836: 48) , nom. illegit. [non Diplopappus villosus Cassini (1819b: 309) , nec Diplopappus villosus ( Pursh 1814: 564) Hooker (1834: 22) ], syn. nov. ≡ Hysterionica villosa Cabrera (1946: 350) . Type:— BRAZIL. Rio Grande do Sul, loco haud indicato, 1835, M. Isabelle s.n. (holotype: K barcode K000250520, ex Herb. Hookerianum).

Neja nidorelloides Candolle (1836: 325) , syn. nov. ≡ Hysterionica nidorelloides (DC.) Baker (1882: 12) . Type:— BRAZIL. Rio Grande do Sul, loco haud indicato, s.d., F. Sellow s.n. = Herbier Impérial du BRÉSIL N. o 1048 (holotype: P barcode P00742833 [F neg. 37686]; isotype: G-DC barcode G00312711).

The herbarium sheet P02484186 has a single specimen mounted on it, which bears an original label annotated by Sprengel with “ Erigeron resinosus * Sello. Rio Grande”, and by Schultz-Bipontinus with “ Neja resinosa Sz Bip. ”. This specimen must be taken as original material of Erigeron resinosus , thus eligible for lectotypification of the name, since it perfectly matches the protolog. It also has another two labels annotated by Schultz-Bipontinus with “ Neja sprengelii Sz Bip in Seemann (Mex ...) = Polyactidium sprengelii Schldl ”, and “ Polyactidium sprengelii Schldl ! DC. vii. 272. (v 282) / Neja resinosa Sz Bip 7/5 52”. Therefore, Schultz-Bipontinus’s annotation clearly indicates the homotypic synonymy between E. resinosus and Polyactidium sprengelii , which is in agreement with Schlechtendal (1835) and Schultz (1856). Baker (1882: 13) and Nesom (1994a: 171) evidently did not check Sprengel’s material in Paris, resulting that the former treated P. sprengelii as synonym of Hysterionica montevidensis (Spreng.) Baker , and the latter placed P. sprengelii as a homotypic synonym of Neja filiformis (Spreng.) Nees , which are misinterpretations. Candolle (1838) clearly and correctly referred to Schlechtendal’s (1835) statement that specimens of Erigeron dubius and E. resinosus would belong to the same species, which he named “ Polyactis sprengelii ”: “Huc ex specim. authent. Sprengeliano species duas refert cl. Schlectendal”.

The herbarium sheet P02484185 has two specimens mounted on it, which belong to the same taxon and closely match the protolog of Erigeron dubius . It bears an original label annotated by Sprengel with “ Erigeron dubius * Sello. Rio Grande”, and a label annotated by Schultz-Bipontinus with “ Neja dubia Sz Bip. 7/5 52”, which denote it is original material of Sprengel’s name. Its taxonomic identity as the same taxon named by Sprengel as Erigeron resinosus , like indicated by Schlechtendal (1835) and Candolle (1838), is accepted here. When compared, the type specimen of E. resinosus is more vigorous than the type of E. dubius , more leafy, but not taller; it also bears more heads, is more viscous, with more glandular trichomes, intermixed trichomes longer, more frequent in the stems; the leaves are longer and slightly wider, but with the same shape and teeth as found in the latter; and with no important differences in the morphology of heads and fruits. These morphological differences fall within the circumscription of the taxon, being the expression of intra and interpopulational variability found in specimens collected within its geographical range.

The herbarium sheet K000250520 has two specimens mounted on it, which belong to the same taxon and closely match the protolog of Diplopappus villosus Hook. & Arn. Once it is a collection by Isabelle, from Rio Grande do Sul, from Herbarium Hookerianum, and annotated with “ Diplopappus villosus H.&A.”, it is taken as the holotype of this name. This Isabelle collection is clearly the same quoted by Baker (1882: 13), in the material examined under Hysterionica montevidensis (Spreng.) sensu Baker , since the sheet was annotated by Baker with “= Erigeron montevidensis Spreng / compared with type 8/80. ...”. Isabelle’s specimen closely matches the type specimens of E. resinosus and E. dubius at Paris, therefore is taken here as a synonym of them.

The herbarium sheet P00742833 has two specimens and a fragment mounted on it, all belonging to the same taxon, and it was annotated by Candolle with “ Neja nidorelloides DC. ”. The specimens and the original label of the Herbier Impérial du Brésil, i.e. “Province de Rio-Grande ... N. o 1048” perfectly match the protolog: “in Brasiliae prov. Rio-Grande (h. Mus. imp. Bras. n. 1048!)” and “(v. s. in h. Mus. reg. Par.)”, thus representing the holotype of this name. A fragment from P00742833, housed at G-DC (G00312711), which was annotated by Candolle with “n. 1048 h. Mus. Bras. / Neja nidorelloides DC. ”, is an isotype. Therefore, Schneider’s et al.(2013) indication of the fragment at G-DC as the holotype of N. nidorelloides is mistaken. Nevertheless, those authors have correctly recognized the collections of Sellow s.n. (K000250519; annotated with “ Neja sprengelii Schtz Bip ”) and of Isabelle s.n. (K000250520, i.e. the holotype of D. villosus ), as belonging to the same taxon as N. nidorelloides . Here, again, the morphological characters of those specimens closely match the circumscription of E. resinosus and E. dubius , which have equal nomenclatural priority over Neja nidorelloides . Another specimen of the Herbier Impérial du Brésil, N. o 862 (P02484188), was annotated by Candolle with doubt as “ Neja nidorelloides DC. ”. Its general morphological aspect closely resembles that of the type specimen of E. resinosus .

Malme (1931) cited four numbered specimens of Sellow under Hysterionica montevidensis sensu Baker , of which only Sellow d 1696 (“inter Rio Pardo et Bagé) ( US 01684160) has been located, whereas Sellow 3350, 3470, 3579 (“S. Gabriel, forte etiam in parte boreali reipublicae Uruguay ”) have not been located up to the present. Since Sellow d 1696 and Malme I 792 (S16-21760, S16-21763) belong to Hysterionica resinosa , the other collections of Sellow cited by Malme might belong to it also. However, another specimen, Sellow 3579, is known to belong to Heliotropium ocellatum Cham. (B † [F neg. 17335; mounted together with Sellow 3649], BR0000006967314, E00394546, G-DC [G00147693], GH00097724, HAL0071612, K000096805, K000096806, L0004006, LE, M0185296, M0188051, P00610211, US 00110868 [Sellow 3401], W0049646; see Förther 1998), indicating a rare example of a duplicate number by Sellow, or that Malme made a mistake.