Najas Marina

Jun, Jul, Aug, Sep, Oct, Nov

Stems up to 150 cm. long, up to 2 mm. in diameter, mostly armed with spines., Herb

Annual

Male flower 2-5 (including spathe-neck) × 0.8-3 mm.; neck of the spathe 0.5-1 mm., tapering at the top, bearing brownish spine-cells at the apex; inner envelope protruding 0.2-0.7 mm. above the anther; anther 1.2-4 × 0.7-2.5 mm. Female 2-5 mm. long; ovary 1-3.5 × 0.3-1.9 mm.; style and stigma 0.3-1.6 mm.; stigma (2-)3(-4)-lobed.

Fruit with persistent membranous pericarp and remnants of style., Seeds not recurved, reddish brown.