Senecio websteri

Calvo, Joel, 2021, On the original material of two austral American Senecio species (Compositae) collected during British naval expeditions in 1828, now located in the herbarium of Geneva, Candollea 76 (2), pp. 261-267 : 264-267

Captain Foster’s Expedition and Senecio websteri

Captain Henry Foster received in 1827 the Copley Medal of the Royal Society for his philosophical experiments in the Arctic Regions, and in 1828 was entrusted by the Lords Commissioners of the Admiralty to sail in the Chanticleer for a voyage to the Southern Atlantic Ocean that lasted from 1828 to 1830. The principal objects of the voyage were experiments with the pendulum, and, next to them, the determination of longitude by means of the chronometer. On Saturday 17 January 1835, the two-penny weekly magazine The Mirror of Literature, Amusement, and Instruction (nº 702) dedicated an article to this expedition starting with the following words: “This is, in many respects, one of the most interesting of all the recent voyages of discovery, and its results to science have been more important than many enterprises of our time”. Indeed, the article is a review of the book Narrative of a voyage to the Southern Atlantic Ocean, in the years 1828, 29, 30 […], which was published in 1834 in two volumes and contained a detailed account of the Chanticleer Voyage written by William H.B. Webster (1793–1875), who was the surgeon of the expedition.

The Chanticleer left Portsmouth on 21 April 1828, and on 16 July harboured in Rio de Janeiro after touring the way Madeira, Tenerife, Cape Verde Islands, and Fernando de Noronha. Then, the expedition sailed southward to Cape Horn visiting Staten Island [“for though an island in itself, and not of very large dimensions either, it is called Staten Land” ( WEBSTER, 1834a: 96–97), Fig. 2 ] and Deception Island during the austral summer of 1828 –1829. After a long passage of twenty-seven days of navigation, on 21 June 1829 they reached the Cape of Good Hope. On 13 December the Chanticleer left the Cape towards St. Helena, Ascension Island, and once again to the Island of Fernando de Noronha (June 1830). Thence, they continued along the coast of South America northward to St. Louis (Maranhão, Brazil), Amazon River, Port of Spain ( Trinidad and Tobago), and La Guaira ( Venezuela). They arrived at Porto Bello (Portobelo, Panama) at the end of 1830 to survey the Isthmus of Darien (Isthmus of Panama). On 5 February 1831 Captain Foster fatefully drowned in Chagres River when he fell from his canoe. Due to this tragic event, the expedition left Porto Bello via Jamaica, Cuba, Crooked Island, Bermuda, and arrived at Falmouth ( England) on 17 May 1831 after completing a voyage of more than three years ( WEBSTER, 1834a; see map depicted to face title page).

Although the expedition was mainly meant to attempt more accurate calculations of the shape of the earth and the law of the variation of gravity in different points of its surface, they were entrusted to take advantage of research in several departments of natural history. The report of the committee on which the foregoing voyage was ordered is clear in this respect and concerning the botanical pursuits stated: “[...] they confine themselves to suggesting that an additional person be appointed to serve with the expedition in the character of botanical collector, whose exclusive duty it shall be to procure and preserve botanical specimens and seeds, and whose collections shall from time to time be delivered to the care of the commanding officer, to be transmitted to England as occasion may occur” ( WEBSTER, 1834b: 380). And it continued as follows: “That Mr. Webster, the surgeon of the ship, be directed to attend to the collection and preservation of specimens in zoology, mineralogy, and geology united; and the Committee will hold themselves in readiness to furnish to Mr. Webster and to the botanical collector, such further instructions in detail as may be required” ( WEBSTER, 1834b: 380–381). The presumed botanical collector is not afterwards mentioned by Webster in his account, which makes one think that Webster himself was who finally held such responsibility. In fact, the botanical specimens originated from this expedition were attributed to him and housed in K. This second statement is not mentioned in Webster’s account but becomes logical knowing the royal nature of the expedition. Moreover, Webster’s specimens are mentioned several times in the later Flora Antartica by Joseph D. Hooker (1817–1911), who developed most of his career in Kew.

Hooker honoured the botanical labours of Webster naming Senecio websteri a very distinct species from Staten Island (Isla de los Estados, Tierra del Fuego, Argentina) that the latter collected sometime between 25 October and 21 December 1828. In another sense, he also emphasized in the protologue that “Mr. Webster’s specimens are very insufficient”. Indeed, referring to the original material of S. websteri, Hooker expressed: “Caulis exemplare a me viso manco 4 unc. longa [the stem of the specimen I saw barely is 4 inches long]”. This sentence reveals with little doubt that Hooker based his description on a single, and sparing, specimen. This material, not located for a long time ( CABRERA, 1949; CABRERA, 1971; FREIRE et al., 2014), has been found in G. The specimen perfectly matches the details stated by Hooker and it bears two labels: (1) shows the name “ Senecio Websteri, H.f. ” in Hooker’s handwriting; (2) reads “Staten Island (Detroit de Magellan) M. Webster”, most probably transcribed from the original source into French by the at that time Herbarium Delessert’s curators Antoine Guillemin or Antoine Lasègue ( Fig. 3 ). On this basis, no reason prevents me from considering this specimen the holotype of the name S. websteri .

Because of the calligraphy in French of the second label, it is quite clear that Webster’s specimen arrived at Geneva through Delessert’s herbarium. However, determining which curator made the transcriptions becomes difficult due to the similarity of their respective calligraphies. Likewise, how and when Delessert acquired Webster’s specimens (I also found a specimen of Senecio eightsii Hook. & Arn. from Staten Island) remain unknown.

Senecio websteri Hook. f., Bot. Antarct. Voy. (Fl. Antarct.) 2: 317. 1846.

Holotypus: A RGENTINA. Tierra del Fuego: Staten Island, s.d. [25.X–21.XII.1828], Webster s.n. ( G [ G00432677 ]!) .

= Senecio websteri var. subdiscoideus A. Gray in Proc. Amer. Acad. Arts 5: 141. 1861. Lectotypus (designated here): CHILE. Magallanes Region: Orange Harbor, Fuegia , [55°31'S 68°05'W], Wilkes Exped. s.n. (US [ US00829297 ] image!; isolecto-: GH image!, K [ K000527618 ] image!).

Notes. – The reniform, orbicular, or flabellate leaf laminas make this species very distinctive among other austral American Senecio ; any confusion seems therefore unlikely.

As pointed out by CABRERA (1949), Senecio websteri var. subdiscoideus is a mere form displaying very short ray florets that does not deserve taxonomic recognition. This name is lectotypified here based on the specimen kept at US, which bears a label handwritten by Gray and it is also the most complete material. The duplicates at GH and K also have labels in Gray’s handwriting but are largely meagre. It is important to note that Wilkes’ material represented the nucleus of the US herbarium, institution that currently houses the main set of this important collection ( BARTLETT, 1940; STAFLEU & COWAN, 1988).

Additional material examined. – ARGENTINA. Tierra del Fuego: Isla de los Estados [as IE hereinafter], Bahia Crossley , islet called Faro Le Maire , 17.X.1971, Dudley et al. 380 A ( E) ; IE , Bahia Crossley , near baliza Tte. Palet, 18.X.1971, Dudley et al. 558 ( E); IE , Pto. San Juan del Salvamento, 26.X.1971, Dudley et al. 928 ( E); IE , Puerto Vancouver, 29.X.1971, Dudley et al. 1037 ( E); IE , Bahia Liberty , 2.XI.1971, Dudley et al. 1252 ( E); IE , Bahia Flinders , 6.XI.1971, Dudley et al. 1501 ( E); IE , Puerto Parry, 11.XI.1971, Dudley et al. 1749 ( E); Cabo San Vicente, north of Bahia Thetis , 23.XI.1969, Goodall 2342 ( US).

Figures

Fig. 2. – Pendulum Station at Port Cook, Staten Island. [WEBSTER, 1834a: 99] [© ETH-Bibliothek Zürich, http://dx.doi.org/10.3931/e-rara-73979]

Fig.3.– Holotype of Senecio websteri Hook. f. [G00432677; Conservatoire et Jardin botaniques de Genève]