Global description
Bolboschoenus maritimus is a vivacious plant with upright stems, tuberous base, which spread along a strong horizontal creeping rhizome. The stems are leafy, trigonal cross-section. The leaves are elongated, pointed at the ends. The inflorescence is usually a very reduced umbel of small yellow to brown oval spikelets underpinned by several leafy bracts with the largest largely exceed it. It can be reduced to a single group of spikelets or even a single spikelet. The fruit is a trigonal, brown to black achene.
Growth habit
Vigorous vivacious plant, with simple erect stems that spread throughout a long creeping rhizome.
Underground system
The underground system is a long creeping network of rhizome, which produces tubers from place to place. Each tuber is the starting point of new rhizomes, it is an organ of resistance for temporary drying of the medium.
Stem
The stem is triangular in section; it measures 30 cm to 1.80 m in height and 3 to 15 mm thick. It has 3-5 regularly spaced leaves.
Leaf
The leaves are simple, alternate, arranged in a tristichous way along the stem. The lamina is elongated, with pointed end. It measures 2 to 12 mm wide and does not or slightly exceeds or slightly the inflorescence. It is flat, scabrous on margins and the keel. Ligule may be absent or present as a small triangular blade.
Inflorescence
The terminal inflorescence is underpinned by 2-5 long leafy bracts that exceed it, the longest usually erect, the other oblique. This is an umbel of spikelets, usually simple, rarely compound, which consists of a set of sessile spikelets and a group of pedicellate spikelets. The inflorescence can be reduced to a single spikelet or a group of sessile spikelets.
Spikelet
The spikelet, ovoid to cylindrical in shape, with pointed tip, measures 8 to 40 mm long and 5 mm in diameter. It is yellowish brown to chestnut brown in colour. The finely marginal scale, bifid at the top, measures 1-3 mm long. It has a long main rib extended in a curved edge.
The flower is made up of 3 stamens and an ovary with trifid style.
Fruit
The fruit is a biconvex to trigonal achene, 2.5 to 4 mm long, brown to black in color with 3 to 6 barbed bristles at the base.