Horse mulla mulla is an indicator of good pasture condition when plant density is relatively high. When it is restricted to discontinuous patches interspersed with degraded patches, it indicates the pasture condition has declined. Cotton bush is a common, important companion plant. Horse mulla mulla and cotton bush often feature prominently in good to fair condition pastures.
Narrow leaf mulla mulla (Ptilotus drummondii) is a similar plant, but grows in sandplain habitat. It is a good condition indicator when the population is strong. It persists at a lower density in country in fair condition. It is more persistent than the desirable warty-leaf eremophila that is also present in sandplain habitat.
Horse mulla mulla is palatable to livestock, but produces only a small amount of feed.
Shallow soils over hardpan, rocky slopes
Horse mulla mulla is small shrub with a woody base. It has lots of upright, near-leafless stems to about 80cm tall, each carrying one compact flower cluster at the tip. The few narrow leaves at the base of each stem are up to 4cm in length and grow from the woody base. The usually pale pink globular flowers fade to white as the seed matures and progressively sheds.
Narrow leaf mulla mulla is a sandplain plant that resembles horse mulla mulla. Narrow leaf mulla mulla flower heads are cream rather than pink, and are significantly larger and more rounded. The flower stalks are more branched; each flower spike branch extends from the axil of a slender, narrowly elliptic leaf. Each leaf has a tiny spine at the tip.