Callitriche lechleri (Hegelm.) Fassett (1951: 191–194

Lansdown, Richard V. & Hassemer, Gustavo, 2021, The genus Callitriche (Plantaginaceae: Callitricheae) in South America, Phytotaxa 501 (1), pp. 85-118 : 102-103

12. Callitriche lechleri (Hegelm.) Fassett (1951: 191–194 , t. 1174[18a–b])

≡ Callitriche marginata var. lechleri Hegelmaier (1867: 12–13) . Type: — CHILE. O’HIGGINS: Rancagua, May–June 1828, C.L.G. Bertero 142 (lectotype [designated by Hassemer & Lansdown 2018: 59]

GH barcode 00048932!; isolectotypes BM!, G barcode G00414770!, MO-1913783!, NY barcode 00248745!, P barcode P04214932!,

P barcode P04214934!, W QR code W0122128!).

Description: —Stem and leaf scales present. Leaves joined across stem. Lingulate leaves 4.3–4.7 × 0.9–1.0 mm, expanded submerged or floating leaves spathulate, 2.7–4.5 × 1.1–3.1 mm, petiole 1.8–7.3 mm, venation fairly simple with a few loops and anastomosing veins outside the secondary veins, the apical leaves forming a floating rosette, leaves of terrestrial plants 5.6–8.0 × 0.8–1.5 mm, narrow and almost parallel-sided. Flowers solitary. Bracts hyaline, 0.6–1.7 mm long. StYles erect, ≤ 3.4 mm. Filament erect, ≤ 3.9 mm; anther 0.3–0.4 mm diameter; pollen Yellow. Fruit not strumose, subsessile, isodiametric or slightly wider than long, grey or greyish-brown when mature, 0.8–1.4 × 0.9–1.5 mm wide, wing narrow throughout 0.02–0.10 mm.

Illustrations: —plate 1174(18a–b) in Fassett (1951); Figures 4–5 in Bacigalupo (1979b); Figure 5 (a).

Distribution:— Callitriche lechleri occurs from southern Chile and Argentina north to Uruguay and Peru to Ecuador. Known altitudinal range: 120–4500 m. See map on page 193 in Fassett (1951).

Notes: — Callitriche lechleri has been the subject of some confusion in the past. The original concept of the species

( Fassett 1951) included C. berteroana as a subspecies and within subsp. lechleri included at least some elements of C. concinna and of C. mandonis , although there was also clearly some overlap with his concept of C. rimosa . Bacigalupo (1979b) and Hassemer & O’Leary (2018) both retained C. lechleri subsp. berteroana and included elements of C. concinna , C. mandonis and C. oblongicarpa within their C. lechleri subsp. lechleri . Through review of herbarium material, it has been possible to shed some light on this taxonomic group. As treated here, C. mandonis includes plants with fruit which are winged at the top and top of the side but unwinged at the base, C. oblongicarpa includes plants with orange-brown, mainly pedicellate fruit which are narrowly winged throughout, C. concinna includes plants with fruit which are small (tYpicallY ≤ 1.0 mm diameter), wider than long and broadlY winged throughout and C. lechleri includes plants with fruit which are more less isodiametric and narrowly winged throughout. However, even with this separation, it is clear that C. lechleri includes quite wide variation. For example, plants from southern Chile and Argentina typically have fruit which are blackish when mature and usually 1.0– 1.1 mm long and wide, whereas the type of C. lechleri and more northern plants have fruit which are maroon to dark brown when mature and usuallY ≥ 1.2 mm long and wide. It is possible that this difference may have a genetic basis, but this can only be clarified through study of fresh material, preferably supported by molecular analysis.

Conservation status: — Callitriche lechleri is classed as Least Concern (LC) as it is widespread throughout much of South America and is not known to be threatened in any part of its range.

Additional material studied: — ARGENTINA. BUENOS AIRES: Camino de las Pilotas, Sierra de la Ventana, Tornquist, 6 December 1964, O. Boelcke et al. 11870 (SI-065663); CHUBUT: En mallin[?] proxima a la cabaña, Lago Vuitter, Tehuelches Dept., 2 February 1889, E.G. Nicora 9478 (SI). NEUQUÉN: [illegible], Pinon Hachado, February 1920, L. Hauman s.n. (BR barcode BR000000024933186); remanso, junto al arroyo, Arroyo Primeros Pinos, 7 km al sudeste de Primeros Pinos, Dpto. Picunches, 12 January 2004, H. Troiani & P. Steibel 15747 (SI-063664); curso inferior, arroyo Benitez, extremo norte de la laguna Varvarco Campas, dpto. Minas, 36º 17’ S, 70º 39’W, 31 January 1970, O. Boelcke 14215 et al. (SI-065633). PATAGONIA. In a little lake, Cabezera Lago at the eastern end of Lago Fagnano, 26 March 1940, R. Santesson 698 (K, P barcode P04214871); Estancia Harberton, white cliffs of Lashifashaj River, 4 March 1968, D.M. Moore 2107 ( US); damp area by Rio Lashifashaj above soil cliffs, Campo Brown Grande, Estancia Harberton, Tierra del Fuego, 54º 50’ S, 67º 27’ W, 4 March 1968, D.M. Moore 2107 (K) (mixed with C. antarctica ); mud and sand at edge of Rio Lainez, near sea, Estancia Irigoyen, Tierra del Fuego, 3 January 1971, R.N. Goodall 2943 (K); RÍO NEGRO: en charco en la ladena, Lago Nahuel, Porto Manzano, casa Sr. José Diem, 4 February 1967, N.M. Bacigalupo 26502 (P barcode P04214951); with Myriophyllum elatinoides and Potamogeton lingulatus , Currhue-W, Parque Nacional Lanín, 4 March 1968, Esk & Klein 1554-4 (G); Pto Moreno, Ee San Ramon Lana Grande- Ensayo 4 Dep. Pilcaneyeu, 8 December 1964, Valierini 528 (SI); SANTA CRUZ: Arroyo camino a Lago Onelli, Bahia Onelli Parque Nacional Los Glaciares, Dpto. Lago Argentino, 16 February 2005, C. Guerrido 664 (SI). BOLIVIA. LA PAZ: [illegible], 8250 m, 29 December 1930, O. Buchtien 8486 ( US). CHILE. [illegible] (P barcode P04214977); 1870, [illegible] (G). ARAUCANÍA: Slow stream in forest along Rio Blanco, “Buenavista”, below Volcan Tolguaca, Malleco Province, 23–25 February 1925, F.W. Pennell 12795 (PH-229192, US); BIOBÍO: Costa, 4 November 1920, Claude-Joseph 1232 ( US); Concepción, San Miguel, 11 November 1933, E. Barros 125 (GH); s.d., C.L.G. Bertero s.n. (F-936330 barcode V0308526F); LOS LAGOS: Marsh, Puerto Montt, Llanquihue, 8 January 1947, B. Sparre 1822 (K); LOS RÍOS: Prope urbem Valdivia, 28 November, W. Lechler 285 (G barcode G00414758, K); Hielol, Temuco, Cautin Province, 120 m, 15 December 1935, G. Montero O. 2589 (GH); in insula Valenzuela pr. Valdivia, Dec. m., R.F. Hohenacker s.n. (P barcode P04214975, P barcode P04214937); Escuela Agricola (Nielol), Temuco, Cautín Province, 38º 44’ S, 72º 35’ W, 15 December 1935, G. Montero 2589 (G); SANTIAGO: [illegible], Magallanes Province, 300 m, January 1931, C.M. Hicken 481 (K); Prov. Magallanes, 300 m, C.M. Hicken s.n. (BM); in humidis ad margines rivularis prope circa la isla d. Valenzuela, Guttifer 26a (K) (on sheet with Lechler 1402 and apparently the same handwriting, annotated by Hegelmaier “ C. turfosa Bert. forma [illegible]”); VALPARAÍSO: Pools near shore between harbour and Valle [illegible], Masatiena, Juan Fernández Islands, 5 January 1955, I. Skottsberg & C. Skottsberg 69 (NY); Qillota, C.L.G. Bertero s.n. (P barcode P04214935). ECUADOR: Pond in pasture, Panamerican Highway 10.3 km S of Caňar, Caňar Province, Ecuador, 78º 55’ W, 02º 36’ S, 3550 m, 25 October 1991, B. Øllgard et al. 99387 (P barcode P00886537). PERU. PUNO: Pond, Capachica Peninsula, Lake Titicaca, 12,500 ft., 7 May 1937, T.G. Tutin 1115 (BM). CUZCO: [illegible] Espinar Province, 4200–4500 m, 24 March 1956, C. Vargas 1196 ( US). HUANCAVELICA: Huaytanayocc-Tansiri, 4500 m, 9 May 1956, O. Tovar 2505 ( US). URUGUAY. Banda Oriental del Uruguay, Voyage d’Auguste de Saint-Hilaire, de 1816 a 1821, C. Catal 2286 (P barcode P04214948, P barcode P04214946); sous l’eau, Cuarein, 25 September 1902, M.B. Berro 2851 (C).

Figures

FIGURE 4. Lectotype of Callitriche heteropoda (G. Mandon 1456, BR barcode BR000000696929). Copyright: Plantentuin Meise.

FIGURE 5. Fruits of South American Callitriche: a—C. lechleri, b—C. mandonis, c—C. nubigena, d—C. oblongicarpa, e—C. praetermissa, f—C. quindiensis, g—C. rimosa, h—C. schotsmaniana, i—C. stagnalis, j—C. terrestris, k—C. turfosa.