Plants of this subspecies of forget-me-not are perennial rosettes which form stoloniferous mats, with long, ebracteate, erect inflorescences, and white corollas with exserted stamens.

dysis was collected from Lake Otuhie, Western Nelson, by Michael Thorsen and is housed at the herbarium of the Museum of New Zealand Te Papa Tongarewa (WELT SP089878).

brockiei is found at higher elevations in montane and subalpine in habitats with limestone or other calcicolous or ultramafic substrates.

brockiei by three minor characters, i.e. its habit (stoloniferous mats instead of single rosettes or tufts instead), obtuse apices of the lower cauline leaves, and lack of retrorse (backward facing) hairs on the scape below the flowering portion of the inflorescence.

The rosette leaf blades are usually 15–50mm long by 4–20 mm wide (length: width ratio 2.5–3.6: 1), oblanceolate or rarely narrowly obovate, widest at or above the middle, with an obtuse apex.

The upper surface of the leaf is densely covered in mostly flexuous, some curved, patent to erect, antrorse (forward-facing) hairs that are oriented oblique to the mid vein.

Each rosette has 1–6 erect, usually once-branched (sometimes unbranched), ebracteate inflorescences that are up to 385 mm long and are bifurcating in an open, forked 'V' shape near the tips.

It is found on faces or ledges of limestone cliffs, on sites with a lowland climate near the coast, and is considered to be an obligate calcicole.

brockiei (a) (CHR 497375; Lake Otuhie)) under the New Zealand Threatened Classification system for plants, with the qualifier "OL" (One Location).