Dymondia margaretae bears alternate, stalkless, oblong to oblanceolate leaves with bluntly pointed or rounded tips on short, branched stems. The thick, spreading blades are channelled, pale green to blue-grey on top and hairless, while whitish felted below. The margins may have a few shallow teeth or only appear wavy, otherwise entire.
The flowerheads are solitary, stalkless daisies comprising several rows of involucral bracts with woolly tips, forming a bell-shaped cup. Above that the yellow head consists of a whorl of spreading, strap-shaped ray florets around a compact disc of tiny, tubular florets that widen at the top. The rays are female, the disc florets bisexual. Flowerhead diameter is about 2,5 cm.
Flowering happens all year round, peaking in spring and early summer. The plant serves and is supported by various insect visitors.
The fruit is a hairless cypsela. It is attached to a pappus with two rings of short hairs or scales that facilitate floating on the wind when ripe and freed from flowerhead bondage (Leistner, (Ed.), 2000; Bond and Goldblatt, 1984; iNaturalist; http://pza.sanbi.org).