Hieracium tenuiflorum Arv.-Touv

Fainelli, Federico, Gottschlich, Günter & Orsenigo, Simone, 2024, Nomenclatural notes on some names in the Hieracium tenuiflorum group (Asteraceae) of the Alps, Phytotaxa 645 (2), pp. 131-148 : 145-146

34. Hieracium tenuiflorum Arv.-Touv . in Bicknell (1896: 173)

≡ Hieracium sylvaticum subsp. tenuiflorum (Arv.-Touv.) Zahn in Reichenbach (1905: 18).

≡ Hieracium murorum subsp. tenuiflorum (Arv.-Touv.) Zahn in Schinz & Keller (1914: 420).

Ind. loc.: —“In the woods and on the slopes of Monte Bignone, Monte Ceppo and Monte Arpetta”.

Type: —[ ITALY, Liguria, Prov. IM] “nei boschi presso Monte Arpetta a 1400 m, 10 Jun 1894, C. Bicknell” (lectotype, designated here: Herbarium Bicknell 25b–56-3!) ( Fig. 1 ).

Syntypes: —[ ITALY. Liguria, Prov. IM] “nei boschi di Monte Bignone, sopra Croce di Para , 28 Mai 1894, C. Bicknell ” (Herbarium Bicknell 25b–56-4!) ; “nei boschi di Monte Ceppo, 13 Oct, 1893, C. Bicknell ” (Herbarium Bicknell 25b–56-5!) ; “ Cima di Monte Ceppo, 1600 m, sopra Baiardo , 24 Jun 1892, C. Bicknell ” (Herbarium Bicknell 25b–56-6!) .

Remarks:—Clarence Bicknell (1842–1918) published the name Hieracium tenuiflorum attributing the species to Jean-Maurice Casimir Arvet-Touvet (1841–1913), with a short diagnosis provided by Arvet-Touvet (“ This is distinguished by M. Arvet-Touvet from the latter species by its smaller flower heads, and its acute involucral bracts, and is perhaps only a form or variety of H. murorum ”) and the habitat (“ in the woods ”).

Few years later Arvet-Touvet confirmed the validity of this species: ” Le H. tenuiflorum (equivalent au H. murorum δ microcephalum Greml. ) nous parait avoir une valeur bien superiéure aux races démembrées du H. murorum d’après la forme des feuilles et l’indument. It se reconnait à ses calathides et périclines presque de moitié plus petites que dans le H. murorum ” [ H. tenuiflorum (equivalent to H. murorum δ microcephalum Greml. ) seems to have a much higher value than the dismembered races (i.e. varieties) of H. murorum recognized according to the shape of the leaves and the indumentum. It can be distinguished by its flower heads and phyllaries almost half the size of those in H. murorum ] ( Briquet 1899).

We traced four specimens in Museum Clarence Bicknell in Bordighera ( Italy) where Bicknell’s herbarium is preserved. Each specimen bears a number handwritten in pencil on the upper angle of the sheet; this number represents a univocal identification code of the specimens. All the specimens were collected by Bicknell between 1892 and 1894 and have annotations handwritten by Arvet-Touvet (“ Hieracium tenuiflorum Arv. T. ?” “var.?” or “forma?”), denoting probably that at the beginning Arvet-Touvet was unsure about the separation of this species from H. murorum L., as stated also by Bicknell in the protologue. All the four specimens can be safely considered as original material. Among these, we select “25b–56-3” as a lectotype of H. tenuiflorum , since it is the richest collection among the original material, consisting of five plants collected in one of the localities cited in the protologue (Monte Arpetta). They are showing the typical features of this species, especially small flower heads with acute phyllaries. All the plants have a single stem with few (2–3) capitula.

Three out of the four specimens bear some additional handwritten annotations by Saverio Belli (1852–1919), Italian hieraciologist, which contain several considerations on the specimens and on the new species described by Arvet-Touvet. On the label attached to the designated lectotype, Belli added: “ Altra forma che dovrebbe appartenere al H. tenuiflorum ma già un po’ differente da quelli di Bajardo. Questa varietà (o forma) è più simile alla mia che raccolsi nei colli Torinesi e in quelli di Como ” [“Another form that should belong to H. tenuiflorum , slightly different from Bajardo specimen. This variety (or form) is more similar to the one that I collected in the hills of Turin and Como”].

The summit of Monte Arpetta falls into the French territory; however, the Italian border runs on the eastern side less than 1 km far from the summit, more or less along the 1400 m contour line. According to the map published by Bicknell in his Flora of Bordighera and San Remo (1896), the collection was made probably in what is today considered the Italian territory.

Current name: — Hieracium tenuiflorum Arv. -Touv.

Figures

FIGURE 1. Lectotype of Hieracium tenuiflorum Arv.-Touv. (10 Jun 1894, C. Bicknell, Herbarium Bicknell 25b-56-3).