Adromischus phillipsiae is confined to the Escarpment Mountains between Verlatenkloof Pass near Sutherland in the Western Cape and northwards to Steinkopf in the Northern Cape. It grows in rocky regions, often on steep slopes and cliffs. When associated with rocky regions away from the cliff, it usually grows below karoo shrubs where it is well camouflaged. It also grows on difficult to reach, sheer cliffs. The substrate varies from mud-rock, sandstone and shale (Adelaide subgroup, Beaufort Group of the Karoo Supergroup) (Johnson et al. 2006).

Rainfall in its habitat occurs mainly during autumn, winter and spring, ranging from 100-150 mm per annum, mainly as cyclonic winter rain, with occasional thunder showers during spring or autumn. The summers are hot with temperatures frequently above 30°C. The winters are cold with frost and occasional snow especially along the southern section of its distribution.

Fig. 4. A south-facing cliff face north west of Steinkopf where Adromischus phillipisiae was discovered by Florent Grenier, and a close-up of Adromischus phillipsiae growing at the base of a species of Mitrophyllum in shade on the cliff.

Near Steinkopf, in its northernmost habitat, Adromischus phillipsiae grows on cooler, south-facing cliffs among lichens, towards the mountain tops which receive frequent fog. Its shares its habitat with succulents such as Crassula tomentosa, Crassula elegans, Mitrophyllum sp. and a yellow flowered species of Conophytum.

Fig. 5. A small cluster of Adromischus phillipsiae growing with Crassula tomentosa on a south-facing cliffs north-west of Steinkopf, the numerous lichens are an indication of fog and dew.

On the escarpment mountains south-east of Calvinia, it grows on sheer cliffs together with a species of Adromischus, a pendent cluster-forming species of Crassula (cf C. lasiantha), Asplenium cordifolium and Haemanthus coccineus.

Fig. 6. Adromischus phillipsiae growing with Crassula lasiantha on a sheer cliff south-east of Calvinia.

West of Calvinia, Adromischus phillipsiae was found on top of the plateau growing in small clusters below Pteronia incana and other low growing karoo shrubs, at an altitude of about 1 600 m above sea level. The soil consists of fragments of mudstone. The plants grow close to the ground, forming compact tufts; they produce lateral subterranean branches to form new rosettes where they protrude from the leaf litter. When not in flower, plants are very difficult to detect below the shrublets. Other succulents commonly encountered in this habitat include Crassula muscosa, Crassula tetragona subsp. connivens, Stomatium pyrodorum (particularly on sand-filled bedrock), Crassula deltoidea, Cotyledon orbiculata and Tylecodon wallichii.

Fig. 7. A cluster of Adromischus phillipsiae growing below a nurse shrub, Pteronia incana in this instance, on a mudstone plateau west of Calvinia (Northern Cape), its leaves are well camouflaged underneath the nurse shrub and its colourful orange-red flowers protrude above it to attract the attention of sunbirds, the main pollinator.