Pachystachys lutea

Pachystachys lutea.

Native to Peru it is commonly known as the Golden candle or Shrimp plant a name it shares with Justicia brandegeeana.
They are evergreen shrubs often around 1 m high but they can reach 2 to 2.5 m.
They have multiple thin stems from the base and the nodes are swollen.
Stems are brown and woody with pale lenticels and vertical streaks.

Leaves, up to around 16 cm long and 5 cm wide are opposite (subopposite) and decussate.
They may have a very short petiole but commonly the blade forms wings down the sides of it.
The wings, up to 1 cm wide have a small lobe at the base.
The dark green blades are elliptic to oblong, spatulate or lanceolate with a pointed tip and a smooth edge.
Veins are prominent on the lower surface and the edge may be wavy.
There are short hairs on the lower midrib and cystoliths on both surfaces.

Terminal inflorescences are dense erect spikes up to 10 or 12 cm long.
Flowers along the spike are in opposite and decussate pairs.
Inflorescences are racemes with the lower flowers opening first.
Each flower is surrounded by ovate bracts and smaller lanceolate bracteoles.

Flowers have an outer (anterior) and inner (posterior) bract with those at the base of the spike being the largest
    at up to 2.5 cm long and 1.5 cm wide.
The bright yellow or orange bracts overlap those above.
They have a round to heart-shaped base and a short pointed tip (mucro).
There are glandular hairs especially on the edges.

The 2 bracteoles, at right angles to the bracts are up to 12 mm long and 4 mm wide.
They have similar hairs to the bracts.

The white flowers, up to around 6 cm long are partly hidden by the bracts.
The calyx is about 1 cm long with 5 sepals forming a bell-shaped base with long pointed lobes.
There are some hairs on the outer surface.

The fused bases of the 5 petals form a narrow, curved funnel-shaped tube with 2 widely spreading lips.
There are hairs on the outer surface.
The upper lip is almost 2 cm long and 5 mm wide with 2 very small lobes.
It forms an erect or curved hood over the stamens.
The 3 lobes in the lower lip are around 3 mm long and 2 mm wide with rounded tips.

There are 2 stamens with 5 cm long filaments that lie under the upper lip of the corolla.
They insert low down in the corolla tube and there are hairs near the filament base.
The anthers have two similar 5 mm long bright green thecae.
The basal lobes of the pollen sacs are long but there are no appendages.

The smooth green 3 to 4 mm long ovary is slightly laterally compressed.
It has 2 locules and ovules with axile placentation.
The fruit are club-shaped capsules around 1.3 cm long with one seed in each chamber.
The 4 mm flattened seeds are forcibly ejected by a 2 mm long retinaculum or jaculator.