In the genus Stylidium, the style and filaments of the flower are fused into a single column. In most
species the column, when stimulated mechanically, undergoes a fast firing movement followed by a slow
resetting movement. This movement is produced by changes in shape of a normally curved region of
the column, the bend. In a wide range of species, the bend has a specialised anatomy and consists
essentially of a longitudinal central layer of cells with two distinctive multi-celled layers of thick-walled
cells on either side. The thick-walled cells are rich in cytoplasm with amyloplasts and vacuoles of varying
sizes, and have non-lignified walls whose cellulose fibrils are arranged approximately transversely. Within
the bend, the phloem occurs as discrete small groups of cells separated by some distance from the xylem.
In species from the subgenus Centridium both the morphology and the internal structure of the bend
differ somewhat from those in most species of Stylidium, and in two species of Stylidium with nonmoving
columns, the characteristic cellular anatomy of the bend is entirely absent.
The specialised anatomy of the cells and tissues in the bend are clearly associated with the movement
of the column. Changes of shape and size of these cells are almost certainly responsible for the change
in shape of the bend.
Novel fast firing method to synthesize tetracalcium phosphate
