Convolvulus crenatifolius subsp. montevidensis (Spreng.) J.R.I.Wood & R.W.Scotland., 2015

Wood, John R. I., Williams, Bethany R. M., Mitchell, Thomas C., Carine, Mark A., Harris, David J. & Scotland, Robert W., 2015, A foundation monograph of Convolvulus L. (Convolvulaceae), PhytoKeys 51, pp. 1-282 : 93-94

52b. Convolvulus crenatifolius subsp. montevidensis (Spreng.) J.R.I.Wood & R.W.Scotland. stat. nov. Figure 8, t. 25-31

Convolvulus montevidensis Spreng., Syst. Veg. [Sprengel] 1: 604. 1824. ( Sprengel 1824: 604). Type. URUGUAY, Montevideo, Sellow s.n. (B†); [URUGUAY], Montevideo, Sellow 278 (neotype NY 00318926, designated here).

Ipomoea montevidensis (Spreng.) G. Don, Gen. Hist. 4: 276. 1838. ( Don 1838: 276). Type. Based on Convolvulus montevidensis Spreng.

Ipomoea ottoensis Choisy, Prodr. [A.P. de Candolle] 9: 378. 1845. ( Choisy 1845: 378). Type. URUGUAY, Montevideo, Otto s.n. (P, not found).

Convolvulus ottonis Meisn., Fl. Bras. (Martius) 7: 311, t. 113. 1869. ( Meisner 1869: 311). Type. BRAZIL, Minas Gerais, Lindberg 165 and URUGUAY, Montevideo, Otto s.n. (syntypes B†).

Convolvulus montevidensis var. megapotamicus Meisn., Fl. Bras. (Martius)7: 312. 1869. ( Meisner 1869: 312). Type. specimen annotated Convolvulus megapotamicus Spreng. (holotype B†).

Convolvulus crenatifolius var. montevidensis (Spreng.) Hallier f., Jahrb. Hamburg. Wiss. Anst. 16, Beih. 3: 34. 1899. ( Hallier 1899: 34). Type. Based on Convolvulus montevidensis Spreng.

Convolvulus crenatifolius var. argentinicus Hallier f., Jahrb. Hamburg. Wiss. Anst. 16, beiheft 3: 34. 1899. ( Hallier 1899: 34). Type. ARGENTINA, Lorentz & Hieronymus 1057, 945, Lorentz 1538, Kuntze s.n.Dec. 1891 (syntypes B, all†)

Convolvulus montevidensis var. ottonis (Meisn.) Chodat & Hassl., Bull. Herb. Boissier, ser. 2, 5: 699. 1905. ( Chodat and Hassler 1905: 699). Type. Based on Convolvulus ottonis Choisy

Type.

Based on Convolvulus montevidensis Spreng.

Distinguishing features.

Distinguished from subsp. crenatifolius by the more slender stems (c. 1 mm diameter on flowering shoots), 1-3-flowered cymes, relatively long pedicels, so inflorescence appears rather lax, and the larger (1.5-2.5 cm long), almost unlobed cream corollas with stigmas very slender, often exserted. The reddish-brown, somewhat scarious, slightly larger (7-9 mm long) outer sepals are often distinctive too. O’Donell 1959: 271-276 p. p., figure 45 under Convolvulus crenatifolius .

Distribution.

Northern Argentina (Renvoize 3072, Tweedie 379, Tressens et al. 2467, Hawkes et al. 3263); Paraguay (Pedersen 60, Jorgensen 4033, Lourteig 2061, Balansa 1066); Uruguay (St.-Hilaire 2384, 2430); Southern Brazil, particularly Rio Grande do Sul (Rambo 46807) and Parana (Kissmann 7788); Bolivia (Villarroel et al. 1466). 0-?1500 m (Upper limit uncertain). Apparently centred on Paraguay.

Notes.

According to the image in Flora Brasiliensis, Convolvulus ottonis represents a plant with broadly elliptic sepals similar to the neotype of Convolvulus montevidensis . The neotype may or may not represent part of the original collection on which Sprengel’s description was based but was collected by Sellow at Montevideo and originates from the Berlin herbarium. It shows the large corolla and reddish brown sepals so characteristic of this subspecies which is common in parts of Paraguay, southern Brazil, northern Argentina and Uruguay.

There is at least one collection from Paraguay (Hansen 7679 [C, NY]) which shows evidence of introgression with Convolvulus hasslerianus . The calyx is that of Convolvulus crenatifolius subsp. montevidensis but the flowers are solitary and the leaves are very shortly petiolate with subentire margins.