Callitriche deflexa A.Braun ex Hegelmaier (1864: 58)

Lansdown, Richard V., Glen, Rene & Hassemer, Gustavo, 2017, Notes on the genus Callitriche (Plantaginaceae) in South Africa, Phytotaxa 317 (3), pp. 219-225 : 224

Callitriche deflexa A.Braun ex Hegelmaier (1864: 58)

Lectotype (designated here):— BRAZIL. RIO DE JANEIRO: 1859, F. Rudio s.n. ( STU; isolectotypes G, GH [3 sheets: 110020570.48927, 110073465.48928 and 110076391.48929], K-000470002, NY, STU).

Note: Hegelmaier (1864) cited three further syntypes (Arkansas, Engelmann s.n. 1835; Pennsylvania, in udis ad M. Conolstown, s.n., herb. Vindob.; Philadelphia, ad ripas fl. Lecha, Moser 1832, pro parte), but considered the Brazilian material to represent the typical form. Consequently a duplicate of the Brazilian collection investigated by him is here designated as the lectotype.

Description: —Plant always terrestrial. Stems terete, creeping and rooting at the nodes. Leaves (1.0–)2.0–4.0 × 0.8– 2.3(–3.0) mm, elliptic; petiole 2.07–3.25 mm × 1.04–1.39 mm; petiole 0.58–1.40 mm, 3 veined, 1 central vein and 2 secondary veins originating near the base of the blade. Generally one male and one female flower together in most or all leaf axils; occasionally a solitary male in one of a pair of axils. Bracts lacking. Styles persistent, 0.4–1.6(–1.8) mm, recurved. Filaments erect, ≤ 0.5 mm. Anthers reniform, 0.19–0.35 mm wide. Pollen yellow, subspherical. Fruits wider than long, sessile or on peduncles up to 6.6 mm ( Bacigalupo 1979); ripe fruits black, 0.7–1.0 mm wide × 0.56–0.80 mm long, winged throughout.

Ecology and distribution: —This is a species of the coastal region of south-eastern Brazil, Uruguay and northeastern Argentina ( Bacigalupo 1979). It occurs as a non-native in Australia, Mauritius, Morocco, Portugal, Reunion, Taiwan and Tanzania ( Schotsman 1977, Cook 2004, Lansdown 2006a, Lansdown 2006b, Bean 2007). In South Africa it has been recorded from various localities in Gauteng, Kwa-Zulu Natal and Mpumalanga Provinces, including the Botanical Garden, Durban, a coastal area at the Raphia Palm Monument, Mtunzini, nurseries at Pietermaritzburg and just outside Amsterdam. In its native range, this species occurs in low-lying, humid areas such as sandy beaches and dry river beds, outside its native range it occurs in a wide range of seasonally or permanently moist conditions such as irrigated areas of nurseries, ornamental beds and greenhouses in botanical gardens, low lying disturbed soil in areas such as un-metalled parking areas and on roadsides.

Additional material studied: — Gauteng: Disturbed clay soil over sandstone in runoff from shade houses, Rosslyn. Malanseuns Nursery, Pretoria District , 10 September 1992, H.F. Glen 3051 ( PRE 782504 ). Kwa-Zulu Natal: On damp soil forming dense mat, Carters Nursery, Pietermaritzburg, 20 Oct 1969, K.D. Gordon-Gray 6258 ( NU) ; abundant along path sides and on ornamental beds, Durban Botanical Garden , 29º 50’ 50.79” E, 31º 00’ 29.16” S, 18 October 2016, R.V. Lansdown & R. Glen ; on the margin of an unmetalled car park, Raphia Palm Monument, Eshowe , 28º 57’ 27.37” E, 31º 45’ 40.61” S, 7 October 2016, R.V. Lansdown, M, H.F., & R. Glen. Mpumalanga: Nugro Seedlings, just outside Amsterdam on the road to Paulpietersburg, Mpumalanga, 2001, C.D.K. Cook s.n. ( NMW), Western Cape: weed of flowerpots, Somerset West, Stellenbosch Division, 13 September 1953, R.N. Parker s.n. ( BOL 4908 ; K) Schotsman (1977) ; weed of wet ground, Faure, Stellenbosch Division , 27 September 1953, R.N. Parker 4915 ( BOL, K) .