Bacopa monnierioides (Chamisso) Robinson (1909: 614)

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 : 9-11

5. Bacopa monnierioides (Chamisso) Robinson (1909: 614) . Fig. 5 .

≡ Ranaria monnierioides Chamisso (1833: 31) ≡ Herpestis ranaria Bentham (1836: 57) nom. illeg. superfl. ≡ Bacopa ranaria Chodat & Hassler (1904: 288) nom. illeg. superfl. ≡ Monniera monnierioides (Cham.) Kuntze (1891: 463) .

Type:— BRAZIL. F. Sellow s.n. (lectotype K 000533423! [designated by Souza & Giulietti 2009: 27], isolectotype HAL 0115853!).

= Bacopa ranaria var. guaranitica Chodat & Hassler (1904: 288) .

Type:— PARAGUAY. “In palude pr. Tobaty, Sep 1900, E. Hassler 6412 (lectotype G00229874! [designated here], isolectotypes BM 000098488!, G 00229872!, G 00229873!, K 000533422!, MPU 020754!, NY 00067876!).

= Caconapea appressa Pennell (1920: 152) .

Type:— COLOMBIA. Meta, moist depression in llano east of Villavicencio, 26 August 1917, F. W. Pennell 1460 (holotype NY00067933!, isotypes CAS0001555!, GH 00078025!, F 0072320F!, K 000533455!, PH 00010106!, US 00122508!).

= Bacopa conferta (Pennell) Standley (1936: 174) ≡ Caconapea conferta Pennell (1920: 153) .

Type:— COLOMBIA. Moist depression, in llano E of Villavicencio, Meta, 1917, F. W. Pennell 1435 (holotype NY 00067934!, isotypes CAS 0001556!, F 0072321F!, GH 00078026!, GH 00078027!, K 000533453!, MO 150748!, PH 00010107!, US 00122509!).

= Bacopa parviflora Standley ex Williams (1972: 118) .

Type:— PANAMA. Prov. Panamá, Tecumen River, vicinity of Juan Díaz, 9 Nov 1017, E.P. Killip 3420 (holotype F 0093089F!).

Herbs, perennial, 5–30 cm tall, erect, branched towards the apex, sub-glabrous. Leaves opposite, sessile, blade elliptic, 8–31 × 8–12 mm, apex rounded or acute, base amplexicaul, margin entire, exceptionally slightly serrate, glabrous or slightly puberulous. Flowers axillary, 2–3 per axil, exceptionally solitary, sessile or with a brief pedicel up to 2 mm long, glabrous; bracteoles two, linear, ca. 1 mm long, glabrous. Calyx 5-lobed, the external dorsal lobe ovate, 1.5–2.5 × 1–1.5 mm, apex obtuse, base rounded, the two lateral lobes ovate, 1–2 × 0.8–1 mm, apex obtuse, base rounded, glabrous, the two internal lobes linear, 1.8–2 × 0.45–0.55 mm, apex acute, glabrous. Corolla white, rarely blue or violet color, tube 1.5–2 mm long, glabrous; stamens 4; ovary glabrous, style entire, stigmatic apex globose or smooth. Capsule ovoid, apex acute, 1.5–2 × 0.85–1 mm.

Distribution and habitat:—This species grows from Panamá to northeastern Argentina, Brazil and Paraguay. It is found in flood plains. It grows between sea level and 500 m elev.

Nomenclatural remarks:— Christenhusz (2010) designated the sheet K [barcode] K000533423 as lectotype of Ranaria monnierioides , not taking into account a previous typification of the species name by Souza & Giulietti (2009). Therefore Christenhusz’s designation should be treated as superfluous.

Chodat & Hassler (1904) mentioned the specimen Hassler 6412 in the protologue of Bacopa ranaria var. guaranitica . Four sheets belonging to this collection were found at herbarium G, where Hassler’s collections from Paraguay are kept ( Stafleu & Cowan 1979). Thus, the specimen showing the best quality of preservation of the important diagnostic features of the taxon is here chosen as lectotype of the name (Art. 9.17).

Taxonomic remarks:— Bacopa monnierioides could be confused with B. paraguariensis (Moore) Hass. or B. scabra (Benth.) Descole & Borsini var. scabra . The three are perennial herbs, branched, erect, with presence of bracteoles. However B. monnierioides is sub-glabrous, and has sessile or briefly petiolate flowers, up to 2 mm long vs. slightly strigose or puberulous plants with floral pedicels longer that 4 mm in both B. paraguariensis and B. scabra var. scabra .

Selected specimens examined:— Corrientes: Ituzaingó, 10 Dec 1973, Krapovickas 24190 B (CTES). Misiones: San Javier, 22 May 1951, Cabrera et al. 282 (CTES).

Figures

FIGURE 5. Bacopa monnierioides. A. Plant aspect. B. Detail of node with two leaves and an axillary flower. C. Flower. D. Corolla opened, showing stamens. E. Calyx with dorsal lobe opened. F. Fructiferous gynoecium. G. Bracteoles. H. Dorsal lobe, external view. I & J. Lateral lobes, external views. K & L. Internal lobes. M. Caspule (from Krapovickas et al. 24190B, CTES).