Bacopa salzmannii (Benth.) Wettstein ex Edwall (1897: 181)

Sosa, María De Las Mercedes, Moroni, Pablo & O’Leary, Nataly, 2018, A taxonomic revision of the genus Bacopa (Gratioleae, Plantaginaceae) in Argentina, Phytotaxa 336 (1), pp. 1-27 : 16

9. Bacopa salzmannii (Benth.) Wettstein ex Edwall (1897: 181) . Fig. 9 .

≡ Herpestis salzmannii Bentham (1836: 58) .

Type:— BRAZIL. Bahia, P. Salzmann s.n. (lectotype K 000533400! [designated here], isolectotypes HAL 0115854!, K 000533400!, MO 503753!).

= Bacopa violacea (Pennell) Standley (1925: 460) ≡ Monocardia violacea Pennell (1920: 156) .

Type:— COLOMBIA. Near Villavicenco, wet loam, along trail in forest, 450 m. elev., 28 Aug 1917, F. W. Pennell 1480 (holotype NY 00090826!, isotypes GH 00078967!, K 000533448!, PH 00018342!, US 00122507!).

= Bacopa humilis (Pennell) Standley (1925: 460) ≡ Monocardia humilis Pennell (1920: 157) .

Type:— COLOMBIA. Huila, “seepy place in plain east of Neiva”, 8 Aug 1917, H. H. Rusby & F.W. Pennell 1065 (holotype NY 00090824!, isotypes GH 00078965!, K 000533452!, PH 00018340!, US 00122505!).

= Bacopa lilacina (Pennell) Standley (1936: 174) ≡ Monocardia lilacina Pennell (1920: 72) .

Type:— COLOMBIA. Meta, in forest near Villavicencio, 28 Aug 1917, F. W. Pennell 1476 (holotype NY 00090825!, isotypes GH 00078966!, K 000533449!, PH 00018341!, US 00122506!).

Herbs, annual, 6–20 cm tall, prostrate, stems ascending, densely hispid villose. Leaves opposite, sessile, blade ovate, 12 × 8 mm, apex obtuse or rounded, base rounded to amplexicaul, margin entire, hispid villose in the margin and on the veins of abaxial face. Flowers axillary, solitary, pedicels (6–) 8–20 mm long, villose, bracteoles absent. Calyx 5- lobed, the external dorsal lobe wide ovate, 4.5–5 × 4.8–5 mm, apex rounded, base cordate, the two lateral lobes wide ovate, 4.8–5 × 4.8–5.2 mm, apex rounded, base cordate, hispid villose in the margin and on the veins, the two internal lobes linear, 4.5–4.8 × 0.8–1 mm, apex acute, base truncate, hispid villose. Corolla white, blue, or pale blue color, tube 5.8–6.2 mm long, glabrous; stamens 4; ovary glabrous, style entire, stigmatic apex globose. Capsule ovoid, apex acute, 3.5–3.8 × 1.8–2.1 mm.

Distribution and habitat:—Species broadly distributed found from Mexico to northern Argentina, between sea level and 1000 m elev. It is found on stony grounds and on lagoon banks.

Nomeclatural remarks:— Souza & Giulietti (2009: 57) and Christenhusz (2011) mentioned that the holotype of Herpestis salzmannii is housed at herbarium K. However two sheets annotated “ Herpestis salzmannii ” by Bentham have been located there. Both specimens agree with the diagnosis and the locality cited in the protologue (i.e. Bahia). Thus, the element showing the best quality of preservation of the important diagnostic features of the taxon is here chosen as lectotype of the name.

Taxonomic remarks:— Bacopa salzmannii is easily distinguished by its dense hispid villose pubescence, also present in B. serpyllifolia . However this last is differentiated by its bifid style and presence of long bristles in a ring around the ovary, vs. entire style and glabrous ovary in B. salzmannii .

Specimens examined:— Chaco: Primero de Mayo, Col. Benítez, 1 Jan 1937, Schulz 9149 (CTES). Corrientes: San Cosme, ruta 12, 28 Sep 1981, Krapovickas et al. 37553 (BAB, CTES, LIL). Formosa: “Guaycalée”, Feb 1919, Jörgensen 3282 (LIL). Misiones: San Ignacio, 29 Dec 2010, Keller 9330 (CTES).

Figures

FIGURE 9. Bacopa salzmannii. A. Plant aspect. B. Detail of nodes. C. Calyx. D. Gynoecium. E. Corolla opened, showing stamens. F. Dorsal lobe, internal view. G & H. Lateral lobes, external views. I & J. Internal lobes (from Arbo 8786, CTES).