Sagittaria guyanensis Kunth.

Common Name : Guyanese arrowhead
Family : Alismataceae

HABIT

IT IS A LACTIFEROUS HERB WITHOUT STOLONS.

STEMS

10-80 CM HIGH.

LEAVES

THE LEAVES ARE FLOATING AND SIMPLE, THE MARGIN ENTIRE, BROADLY ARROW-HEAD SHAPED AND OVAL IN OUTLINE, AND 3-12 X 2.5-11 CM. THE LEAF TIP IS
OBTUSE-ROUNDED, AND THE BASE IS DEEPLY CORDATE AND SAGITTATE WITH TWO BROAD DIVERGING LOBES; THE PETIOLE IS USUALLY ABOUT 15-30 CM LONG, SEPTATE, WITH AIR-DUCTS; THE BASAL PART HAS A BROAD, MEMBRANOUS SHEATH.

FLOWERS

THE INFLORESCENCE IS A RACEME; THE PEDUNCLE IS
FLACCID, 10-30 CM LONG, WITH SEVERAL WHORLS OF FLOWERS ATTACHED TO THE MAIN AXIS. FLOWERS ARE MAINLY UNISEXUAL; BISEXUAL FLOWERS ARE USUALLY IN LOWER WHORLS.

FRUITS

FRUIT IS A NODDING AGGREGATE ON A STRONGLY THICKENED PEDICEL. THE FRUIT AGGREGATE IS ABOUT 10-15 MM IN DIAMETER.

SEEDS

THE SEEDS ARE BROWN, 1.5 MM LONG; THE EXOCARP HAS A BLUNT, BROAD SPINY CREST.