Senecio banksii Hook.f.
S. odoratus Hook. f. Handbk N.Z. Fl. 1864, 160 non Hornemann Hort. hafn. 2, 1815, 809.
Hooker's description is: "The S. Banksii in its usual form is a rather slender, branched, perfectly smooth plant, with flexuose, leafy, grooved stems and shining foliage. Leaves all sessile, 3-5 inches long, linear-oblong, acuminate, irregularly toothed, below deeply two-lobed, and embracing the stem with two rounded auricles. Corymbs lax, branching, of rather small heads, on slender pedicels. Involucre 1/6 inch long, of slender, blunt [acutis in Latin diagnosis], smooth or sparingly pubescent scales, much shorter than the pappus, which is white, very soft, and of slender hairs. Ray florets few, with short ligulae. Achenia long and slender for the size of the capitulum, nearly as long as the involucral scales, grooved and pubescent.-The varieties ß [velleia] and γ [scabrosus] may belong to different species, but my specimens of them are very indifferent. Var. ß is a very thickly leathery-leaved plant, with stout stem and branches of the corymb, which bears very numerous broader heads, that have much shorter achenia. Var. γ again is a more rigid plant, covered on the stem and under surface of the leaf with hispid scattered hairs."
"Hab. Northern Island. East Coast, Banks and Solander, Colenso."
Cheeseman lists coastal localities from Mokohinau Id, Mercury Bay and East Cape to Gisborne, and inland at Taupo. N. L. Elder reports finding related plants as far south as Taradale and as far inland as Te Haroto on the Taupo Rd, and the northern tip of the Ruahine Range.
In the Handbk 1864, 160 Hooker refers his sp. to S. odoratus Hornemann and does not refer to vars. In the Handbk 1867, 734, he adds specimens from "Banks Peninsula, Haast" and readopts the name S. Banksii. The Banks and Solander types, presumably at BM, have not been examined.
There has been much dispute as to the circumscription of S. banksii and especially of the status of S. pumiceus Col. which was described (T.N.Z.I. 21, 1889, 89) as follows: "A suberect glabrous perennial herb, 2 ft.-3 ft. high . . . slender and sub-flexuous . . . leaves . . . sessile, half-clasping: the lower ones on main stems close, oblong, 41/2 in. long, 11/2 in.-2 in. broad . . . margins grossly serrate and slightly revolute; tip acute; base cordate: the upper leaves on flowering stems linear-oblong (sometimes lanceolate), 2 in.-3 in. long, 1/2 in.-1 in. wide, sparingly toothed (teeth very small) and entire . . . Involucre . . . lobes 13, oblong-ovate, about 1 line wide, suddenly subacuminate . . . Ray-florets 10, ligulate, 31/2 lines long . . . achenes linear, 1/10 in. long . . . 'Face of pumice rocky boulders near the sea, Whangawehi' (cliffs, north side of Table Cape, East Coast); January, 1888: Mr. A. Hamilton." Colenso suggests that his sp. may be the var. ß velleia of Hook. f.
Kirk (Stud. Fl. 1899, 342-343) accepts, probably rightly, S. banksii Hook. f. and S. pumiceus Col. as separate spp. and refers Hooker's var. velleia to the latter. He describes var. angustatus of S. pumiceus giving S. banksii var. γ scabrosus Hook. f. as a synonym. Kirk's key (loc. cit. 337) is:
Stem zigzag. Leaves glaucous, oblong-ovate, amplexicaul. Heads 1/4 in. broad. Rays about 10......S. Banksii
Stem erect, 2 ft.-5 ft. high. Leaves 2 in.-4 in. long, 11/2 in. broad, amplexicaul, broadly oblong; veins prominent beneath. Heads ⅓ in. broad S.
Leaves lanceolate, acute or acuminate......var. angustatus
Cheeseman (Man. N.Z. Fl. 1925, 1018) accepts only S. banksii Hook. f., placing S. pumiceus Col. as a synonym. He places var. angustatus under S. banksii, giving as synonyms S. banksii var. scabrosus Hook. f. and S. pumiceus var. angustatus Kirk. Why the epithet scabrosus is dropped is not explained. Cheeseman supports his treatment by the statement: "A series of the Tolaga Bay plant, which is that collected by Banks and Solander, shows that this distinction [between S. banksii and S. pumiceus] cannot possibly be maintained, some of the specimens exactly matching the types of S. pumiceus in Mr. Colenso's herbarium, while others show a regular gradation to more slender and membranous forms. An examination of the ripe achenes of both varieties also proves that the supposed difference in size and shape does not exist."
However, there is some field evidence that there exists a complex group connected by hybridism, and there is need for a thorough revision.
