Rumex uliginosus, , Gussone, 1826

Iamonico, Duilio, Domina, Gianniantonio & Conti, Fabio, 2023, On the identity of Rumex uliginosus and the occurrence of R. dentatus in Italy (Polygonaceae), Phytotaxa 619 (1), pp. 105-110 : 106-107

Typification of Rumex uliginosus

Gussone (1826: 151‒152) provided detailed diagnosis and description, and reported the habitat and provenance (“In humentibus huliginosis Aprutii; presso le sponde del lago Fucino” = “In humid and dusty places of Abruzzo [a region of central Italy]; near the banks of the lake Fucino”); moreover, a synonym from Boccone (1697: “ Lapanthum aquaticum luteolae folio ”) was cited and it refers to an illustration (“ t. 104 ”) which is original material for the name Rumex uliginosus . To note that Boccone’s illustration was cited by both Smith (1800: 394) as synonym of R. palustris (see above under the paragraph “ Typification of Rumex palustris ”) and by Linnaeus (1753: 335) as synonym of R. maritimus L. So, Gussone (1826) interpreted Boccone’s illustration as a separated species, not only from R. palustris (as discussed above; see “ Typification of Rumex palustris ”) but also from R. maritimus (see discussion below).

We traced two specimens included in Gussone’s collection at NAP (see HUH Index of botanists 2013b) bearing plants collected at “ San Benedetto al Fucino ” (“ San Benedetto ”, currently known as San Benedetto dei Marsi, is a small town of Abruzzo region located on the eastern side of the Fucino plain, an Apennine basin which was am endorheic lake up to 1878 when was drained) in september 1823 (barcodes NAP0002063 and NAP0002066). These two NAP specimens are part of the original material for the name Rumex uliginosus .

Among the original material found (Boccone’s illustration and specimens NAP0002063 and NAP0002066), we prefer to consider the herbarium specimens which are better choice against the illustrations because of their potential ability to provide large number of additional characters (micro-morphological, chemical, molecular, etc.) that cannot be matched by images (see Jarvis 2007: 21–22). Since NAP0002066 appears to be better preserved and includes more leaves, whose features are important diagnostic characters for the genus Rumex ( Akeroyd 1993, Galasso 2018), we here designated it as the lectotype of Rumex uliginosus . Note that NAP0002066 bears three plants, but they are clearly part of the same gathering.

Concerning the identity of Rumex uliginosus, Gussone (1826: 152) discussed this new species in comparison with R. maritimus from which would differ, according to the author, being an annual or biennal plant (vs. perennial for R. maritimus ), basal leaves petioled (vs. sessile), and fruiting valves ovate-lanceolate (vs. deltoids). However, R. maritimus is an annual to perennial species (not only perennial as stated by Gussone 1826: 152). Actually, this author stated: “Icon Bocconi superius citata hanc speciem exacte refert, quamvis a Willd., et a Lin., ad R. maritimus , et inde cl. Smithio l. c. ad R. palustre sit relata. Interim fateor, quod dubius adhuc haereo, an haec species sit a R. maritimo revera diversa, cum nec specimina exsiccata, nec iconam bonam adhuc viderim.” (= Boccone’s iconography refers to this species [ Rumex uliginosus ] although Willdenow and Linnaeus reported it as R. maritimus and Smith as related to R. palustris . Meanwhile, I admit that I have still doubts if this species [ Rumex uliginosus ] is different from R. maritimus , since I did not still seen neither collected specimens nor a good illustration). So, Gussone (1826: 152) did not well know R. maritimus and his proposal refers, in fact, to a comparison with a Smith’s description (“Quantum ex descriptione Smithii consequi licet ...” = As we can deduce from the description by Smith ...”). According to the current concept in Rumex (see e.g., Akeroyd 1993, Galasso 2018), we can exclude R. maritimus which displays valves up to 3 mm long (vs. 3–5 mm in R. uliginosus ) with teeth 1.5–3.0 times longer than the width of the valves (vs. as long as the width of the valves), and tubercules much narrower than the width of the valves (vs. as wide as the valves). Concerning R. dentatus and R. palustris , their morphological differences regard the basal leaves (2–3 times longer than wide in R. dentatus vs. 4–6 times in R. palustris ) and the teeth of the fruting valves (3–6 mm vs. 1.0–2.0 mm). Rumex uliginosus has basal leaves about 6 times longer than wide and teeth of the fruiting valves up to 2 mm long (as in R. palustris ). We also verified the characters of valves in the lectotype of R. dentatus [LINN no. 464.12 (designated by Graham 1958: 9, available at https://linnean-online.org/4151/#?s=0&cv=0&z=0.3754%2C0.7302%2C0.1762%2C0.1586] where teeth are 3 mm long on average (clearly longer than the width of the valves).

Rumex uliginosus Gussone (1826: 152) does not seem match with R. dentatus (as reported, e.g., by Galasso 2018: 83) and despite the small size and that, according to Gussone, it can behave as annual, due to the other characteristics related to the morphology of the valves and leaves must to be considered synonym of R. palustris (as reported, e.g., by POWO 2023).

Rumex palustris Sm., Fl. Brit. 1: 394. 1800 ≡ Lapathum palustre (Sm.) Gray , Nat. Arr. Brit. Pl. 2: 275. 1821 (published in 1822) ≡ Rumex limosus var. palustris (Sm.) Rouy in G.Rouy & J.Foucaud, Fl. France 12: 79. 1910.

Lectotype (designated here):— GREAT BRITAIN. England, Norfolk, 1781, Pitchford s.n. (LINN-634.5!, plant no. 1); image of the lectotype available at https://plants.jstor.org/stable/viewer/10.5555/al.ap.specimen.linn-hs634-5-1.

= Rumex uliginosus Guss., Pl. Rar.: 151. 1826 ≡ Rumex palustris subsp. uliginosus (Guss.) Arcang. , Comp. Fl. Ital.: 585. 1882.

Lectotype (designated here):— ITALY. Abruzzo, San Benedetto al Fucino, september 1823, Gussone s.n. (NAP0002066!, Fig. 1 ).

Notes: —The occurrence in Italy of Rumex dentatus is based on an old record of R. uliginosus by Lojacono - Pojero (1907: 298) at “Luoghi acquitrinosi, Palermo a Boccadifalco” (= humid places, Palermo at Boccadifalco”, where “Boccadifalco” is a locality now included in the city Palermo, NW-Sicily). In fact, Galasso (2018: 83) listed the Gussone’s name as an heterotypic synonym of the Linnaean R. dentatus . However, as discussed in the present paper, R. uliginosus cannot be ascribed to R. dentatus . Moreover, R. uliginosus was described from Abruzzo (a region of central Italy), not from Sicily (southern Italy) as indicated by the Italian authors. To note, also, that Gussone (1842), in his Florae siculae synopsis, did not list R. uliginosus . We checked the Herbarium PAL, that was studied by Lojacono-Pojero, but the specimens by Agostino Todaro collected at Boccadifalco reported by Lojacono-Pojero was not found. All things considered, R. dentatus is to be excluded from the flora of Italy. According to our observations, R. uliginosus is considered as synonym of R. palustris . On the other hand, the occurrence of R. palustris is doubtfully in Sicily [Boccadifalco, based on Lojacono - Pojero (1907: 298, sub S. uliginosus )] (no specimen was found for this region).

Other specimens examined: — ITALY. Abruzzo, San Benedetto al Fucino, Sep 1823, Gussone s.n. (NAP0002063!).

Figures

FIGURE 1. Lectotype of the name Rumes uliginosus, NAP (barcode NAP0002066!).