This is justicia carnea more commonly known as Jacobinia, Brazilian plume, King’s Crown or Plume Flower. It hails from South America and grows in the U.S. in Zones 9 to 11 but will come back from the root in Zone 8.
It was blooming yesterday next to the steps where I have about 3 plants in filtered shade. I have another 5 or 6 in the Wildflower Bed grouped in a mass planting in deeper shade where it thrives. According to Floridata, there are additional colors in white, pink, red, orange, purple and yellow. I have two colors — pink and pastel pink.
It makes a great passalong plant because it is very easy to root but the stems remind me of bamboo – hollow and jointed.
Here it is in full of blooms and almost-blooms: