Thelocactus lloydii Britton & Rose, Cact. 4: 11 (1923).

   Plants simple, depressed-globose, 8 to 12 cm. broad, pale bluish green, strongly tubercled and strongly armed; tubercles conspicuous but low, often wider than long, sometimes 4 cm. wide; flowering groove rather conspicuous but narrow, extending from spines to about half-way to axil of tubercle; spines usually 8, sometimes with a smaller accessory one, all ascending from base and curved outward from middle, terete or somewhat angled at base, often highly colored below with sharp yellowish-crimson tips, the longer ones 6 cm. long; outer perianth-segments very pale purple, never deep purplish pink; filaments white; anthers deep yellow; style yellowish, pinkish at top; stigma-lobes pinkish yellow.