Lagarosiphon madagascariensis Casp.

Global description

Lagarosiphon madagascariensis is an emerged plant with linear leaves in whorls, white male flowers emerged and greenish female flowers submerged.
 
General habit

Lagarosiphon madagascariensis is a small grass with dense linear leaves, completely submerged, branched, with appearance of a dense green algae.
 
Underground system

Taproot system
 
Stem
 
The stem is slender, vary in height depending on the depth of water, more or less branched.
 
Leaf
 
The leaves are simple and alternate, small, linear, numerous and more or less grouped in whorls of variable length (from 8 to 25 mm) of 0.8 to 2 mm wide, with small hyaline tines on the margin.
 
Flower
 
Isolated small white flowers, unisexual carried by a long stalk of the size of a hair. The male flowers are white, emerged, with very small perianth, 1.5 to 2 mm in diameter, with very small more or less elongated tube, of 5 to 35 mm; the female flowers are always submerged, also in small perianth with more or less elongated tube, green and less hail.
 
Fruit
 
The fruit has an oval shape, of 2.5 to 4 mm 1 to 2 mm, more or less extended by the tube.
 
Seed
 
Seeds are few (5-6), olive, perfectly elliptical (1.2 mm to 0.5 mm).

https://www.gbif.org/fr/species/2865567