Achiote, native to Central America is the source of an orange-red pigment.
They are shrubs around 2 to 5 m or small trees 10 to 15 m high with a trunk 15 cm or more across.
They are widely cultivated around the world but can be invasive.
Usually evergreen they may loose some leaves in summer.
New and small branchlets are densely covered in rust coloured scales.
Scales are peltate with a short stalk attached near the centre of the scale.
Older branches have no scales but do have some lenticels (small nodules).
The alternately arranged leaves are on a petiole that can up nearly 15 cm long.
It has a swollen pulvinus at each end allowing the blade to fold and the leaf to move.
The petiole and pulvini are covered in reddish scales.
The stipules, around 1.5 cm long, fall early leaving a green scar with 2 glands.
Blades, up to around 25 cm long and 17 cm wide are triangular or, with a cordate base they are heart-shaped.
There is a long tapering pointed tip and the edge is smooth.
The 5 main veins from the base (palmate) are very prominent on the lower surface.
The upper surface is green to dark green and the lower is paler.
New leaves are rust-coloured with dense peltate scales on both surfaces.
Scales rub off easily and adult leaves have few or none.
Terminal inflorescences are clusters of a few to many flowers.
The midrib is rust-coloured with scales like those on the leaves.
Bracts up to 1 cm long at the base of the peduncles and bracteoles on the pedicels all fall early.
The midrib, and the up to 1 cm long pedicels have dense rust coloured scales.
The 5 obovate sepals, around 1 cm long have peltate scales on the outer surface.
There are a few glands at the base of the purplish sepals.
The 5 (7) flaring petals form a corolla up to 5 cm across.
The obovate petals may be unequal in size or shape.
The are a bright pink, mauve or white with red veins and streaks.
The many stamens have filaments up to 1.5 cm long.
The violet or red anthers open through an apical pore.
The roughly spherical superior ovary is a few mms long.
It is covered in sparse to dense reddish bristles.
The style, up to 1.5 cm long is thicker towards the end.
The fruit are clusters of capsules up to around 4.5 cm long and slightly narrower.
Shape varies but most are roughly spherical or ovoid with a pointed tip.
The brown to bright red capsules are typically covered in dense soft spines.
Spines at the base are the longest at up to 12 or 15 mm.
Capsules split into 2 sections or valves starting at the tip and spreading to the base.
The around 40 seeds are on a stalk (funiculus) a few mms long that widens where it joins the seed.
The slightly flattened obovate 5 mm long seeds are attached at their narrow end.
At the blunt (distal) end is a dark brown spot surrounded by a pale brown disc.
From the disc a pale groove runs down one side.
The dark black-brown surface is covered in tiny bright red glands.
J.F.
