Teucrium grandiusculum is a species of flowering plant in the family Lamiaceae and is endemic to central Australia.

Teucrium grandiusculum is a perennial herb or shrub that typically grows to a height of 80 cm (31 in) with stems that are square in cross-section and covered with glandular hairs.

The sepals are 6–8 mm (0.24–0.31 in) long and joined along their lower half, the petals are white and there are four stamens.

[2][3] Teucrium grandiusculum was formally described in 1890 by Ferdinand von Mueller and Ralph Tate in Transactions, Proceedings and Report, Royal Society of South Australia.

[6] In 1985, Hellmut R. Toelken described two subspecies of T. grandiusculum and the names are accepted by the Australian Plant Census:[3] This germander grows on rocky slopes and along watercourses in scattered locations on the Tomkinson Ranges near the border between Western Australia, South Australia the Northern Territory.