Cleistocactus straussii features cylindrical, grey/green stems that grow upright, forming dense clumps over time.
The stems have prominent ribs adorned with white woolly areoles, from which spines emerge.
The spines are usually brownish or reddish and can vary in length, providing a visually appealing contrast against the silvery-white wool.
The stems can reach heights of up to 1-1.5 metres and spread to around the same.
During the flowering season, which typically occurs in late spring to early summer, it produces vibrant red or orange tubular flowers that emerge from the top of the stems.