Pachystachys.
From Central and South America there are 12 (The Plant List) to 18 (Kew) species.
They are evergreen shrubs 1 to 2 m high with a woody base and can climb up to 3 m.
The opposite and decussate leaves are on petioles.
They can be elliptic, oblong, spatulate or ovate and from 8 to 15 cm long.
Some have a wavy edge.
Inflorescences are erect terminal spikes from 6 to 20 cm long.
The opposite and decussate flowers are subtended by large bracts and small bracteoles.
The bracts are modified leaves from 1.5 to 4.5 cm long and 6 to 18 mm wide.
They can be ovate, narrow or widely elliptic, lanceolate or oblanceolate.
Some have a 1 mm long mucro on the rounded tip.
They can be dark or yellowish green or green with a purple or brownish tip.
The main veins on the lower surface may or may not be prominent.
Some have dense hairs, sometimes glandular while others only have a few.
The bracts are important in differentiating the species.
The tiny linear bracteoles are up to 8 mm long and 1.5 mm wide.
The calyx has a tubular base with 5 triangular to lanceolate lobes.
Lobes are 3 to 12 mm long by 0.5 to 1 mm wide.
The bilabiate corolla is from 4 to 8 cm long.
It has a narrow curved obconic base with widely spreading lips.
The narrow upper lip, erect or curved back has 2 lobes with rounded tips.
Lobes are 1 to 1.5 mm long and 0.5 to 1.2 mm wide.
The lower lip has 3 oblong or ovate lobes that are of slightly different sizes.
The corolla can be white, crimson, pink or an orange-red.
The outer surface has some hairs.
The 2 stamens insert near the base of the corolla tube.
They are about the same length as the upper lip under which they lie.
The anthers have thecae or pollen sacs of equal size and no appendages.
There is a nectiferous disc around the base of the ovary.
There are no hairs on the ovary which has 2 locules.
There is a single long style that extends to or past the upper corolla lip.
The fruit are capsules with seeds ejected by a retinaculum or jaculator.
Three species, P. Lutea and the red-flowered P. spicata and P. coccinea are seen in gardens.
J.F.
