Drimia comprises bulbous, mostly deciduous herbs, the perennial bulbs varying much in size, sometimes forming clumps as in the photo. The ovoid to globose bulbs consist of loose scales that overlap each other. The roots under the bulb are often swollen and branched.
Drimia flowers have subtending bracts that are spurred, outgrowths on the lower side near the bract base. The lower flowers in the raceme have larger spurs. Each flower lasts for about a day.
Drimias grow one to fifteen leaves annually, usually after flowering. The leaves are highly variable. In shape they may be terete (cylindrical), linear (narrowly oblong) or strap-shaped.
The clump of large-bulbed plants in picture were seen in southern Namaqualand during August. Their broad, grey-green leaves taper to acute tips, the blades longitudinally lined with fine undulations.
Three South African Drimia species were found bearing broad leaves somewhat similar to the ones shown here:
Drimia capensis may occur in the area (Manning, 2007) or only in the Eastern Cape (http://redlist.sanbi.org). It clumps, the erect, broad leaves may be shaped roughly as in picture, the colour variable, some similar to what is shown here (iNaturalist).
D. altissima, the tall white squill, previously D. barteri and D. paolii, also housed botanically in Urginea and Scilla in the past, is found from the Western Cape to Limpopo. Its leaves vary from bright green to blue-grey, also in width and the angles at which they are borne.
D. elata, previously D. robusta (and more), is reported in http://redlist.sanbi.org to grow in all provinces but the Western Cape. It has a variety of leaf shapes: some broad but short, some prostrate, others with wavy margins and several in shades of grey. Overlap between D. elata and D. altissima, or a lingering grey area between their identities is likely.
The input given here does not yield a definitive answer. Have fun with the inconsistencies in the reported information. Plant identities are sometimes fraught with mystery and enigma, driving the need for certainty and precision in some people. Answers and mistakes can look so similar when information is incomplete.
Comparing flowers will yield better answers, requiring revisits in the appropriate seasons. An improved answer will arrive tomorrow or the day after. That is what hope and persistence keep promising.
These plants have been here for a long time. They can wait and play with you (Manning, 2007; Leistner, (Ed.), 2000; Lowrey and Wright, 1987; iNaturalist; http://redlist.sanbi.org).