Ottelia ulvifolia (Planch.) Walp.

Global Description

Ottelia ulvifolia is an aquatic, sub-acauline grass of freshwater, in dense clumps as high as the depth of the waters in which they grow, forming genuine aquatic meadows. The leaves are radical, submerged or free-swimming, with lamina of variable shape and dimensions, with undulated edges, base attenuate into long petiole. Solitary and hermaphrodite yellow flowers blossom on the surface of the water. Each flower is held in a compressed spathe, 3 to 6 cm long, with long flat peduncle, consist of 3 green narrow sepals, 3 yellow obovate fragile petals.
 
Growth habit

Ottelia ulvifolia is an annual, sub-acauline aquatic grass of freshwater, forming dense clumps of size proportional to the depth of the water.
           
Underground system

The roots are fibrous.
 
Stem

The plant is almost stemless.
 
Leaf

The leaves are all radical emerging from a bulbous base. They are submerged or floating on the surface, with lanceolate blade of very variable size, reaching up to 23 cm long (average 15 cm) by 13 cm wide in the middle (average: 5 cm), with wavy margin, attenuated at the base in a long petiole and shortly-acuminate at the apex. Both sides are glabrous.
 
Inflorescence

The flowers are solitary, axillary (1-4 per plant)
 
Flower
 
The flowers are usually hermaphrodites. Each flower is in a compressed spathe, 3 to 6 cm long, with winged edges, at the end of a long flat peduncle. Each flower consists of:
- 3 membranous, green, oblong, sepals, 15 to 20 mm long and 3 to 6 mm wide, fairly rigid;
- 3 yellow petals broadly obovate, much larger than the sepals, 3 cm wide and high, very fragile;
- 6 to 8 short epigynous stamens, with more or less expanded filament: the anthers are oblong, with lateral dehiscence;
- 1 inferior ovary with 6 carpels, very slightly spiral bulkheads, with 6 bifid styles, longer than the stamens.
           
Fruit

The fruit is a sort of oblong-cylindrical berry, somewhat swollen in club at the top, 4 to 6 cm long and 1 to 2 cm wide, which remains in the spathe. It contains many seeds.
 
Seed

Seeds are small, numerous, oblong, grayish, amid a mucilaginous pulp.