Myriophyllum verticillatum
Content
Description
Aquatic, sometimes semiterrestrial.
Flowers solitary in the middle and upper leaf-axils, mostly ☿, the upper sometimes ♂, the lower ones often ♀, sessile or subsessile.
Sepals triangular, acute, serrate, c. 1 by 0.8 mm, erect, in ♀ up to 0.3 by 0.4 mm.
Petals c. 3-4 mm long, rose, erectopatent in anthesis, caducous after anthesis, strongly reduced in ♀ flowers and covered by the styles.
Stamens 8;
Fruit ovoid, in section ± quadrangular with dorsally rounded, smooth mericarps, c. 3 by 3 mm.
Distribution
African Mediterranean present, Asia present, Asia-Tropical, Canada, from British Columbia to New Foundland, south to Maryland and California present, Europe present: Iceland (Iceland absent), Greenland absent, North America present, W. New Guinea, Wissel Lakes, north to Lapland present, temperate and boreal, east to Kamchatka and Japan, south to Afghanistan and Kashmir present
Europe (north to Lapland, not in Iceland and Greenland; including the African Mediterranean), Asia (temperate and boreal, east to Kamchatka and Japan, south to Afghanistan and Kashmir), North America (Canada, from British Columbia to New Foundland, south to Maryland and California); in Malesia: possibly found in W. New Guinea (Wissel Lakes, 1600 m).
Notes
The New Guinean collection (EYMA 4733) is sterile. Identification of vegetative plants is extremely difficult in this genus. I share the opinion of SINCLAIR, l.c., that this collection may belong to M. verticillatum, although it is not impossible that it should turn out to belong to M. propinquum.
Flower characters in the description are taken from extra-Malesian material.
Flower characters in the description are taken from extra-Malesian material.