This tall palm can reach 15 to 25 metres in height. Its long, slender stem has a diameter of between 3 and 20 cm and is covered in black spines, which can be very dense.
Palms of this species are clumping palms, meaning they grow in dense, tight, and compact clusters, often with dozens of stems growing from a single base.
The leaves (also called palm fronds) are pinnate and can grow up to 2 or 3 meters in length. They are rigid and bowed and have a short petiole. Both the leaves and the petiole are also covered in spines. Depending on the age of the plant, palm leaves can be made up of between 40 to 80 leaflets, also called folioles.
The inflorescence is protected by a robust and slightly fibrous spathe (modified bract). Male flowers are small and cream-coloured, whereas female flowers are globular, often greenish in colour, and form small clusters at the base of each inflorescence.
The fruits are oblong drupes that are between 3 and 6 cm long. They are yellow-orange and turn bright red when ripe.
Unlike trees, palms are herbaceous plants that don’t grow trunks. Because they do not produce wood, their stems do not get bigger every year.
There are other species in the Bactris genus, including the Bactris glandulosa palm, which is most found in the western Amazon. The name of the species (glandulosa) comes from the presence of glands on the rachis (the leaf’s main axis or stem). This other species of spiney clumping palm is found along riverbanks in tropical lowland rainforests.