Echinocactus platyacanthus (Biznaga de dulce)

Echinocactus platyacanthus Link & Otto 1827

Biznaga de dulce, biznaga gigante, giant barrel cactus, giant biznaga, large barrel cactus

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Caryophyllidae	Cacti, many other succulents, carnivorous plants, and leadworts
Order	Caryophyllales	Includes cacti, carnations, amaranths, ice plants, and many carnivorous plants
Family	Cactaceae	Succulent (water-storing) plants, often spiny
Genus	Echinocactus	From echinos, “hedgehog or spine,” and cactus
Species	platyacanthus	From Latin platy, "flat, broad or wide," and acanth, "spiny bush" (from Stearn's Botanical Latin)

About plant names...

Biznaga de dulce (roughly “sweet thorny cactus”) is native to northern and central Mexico.

Identification: These cacti are generally spherical in shape, though they may appear more columnar or barrel-shaped. They reach 20-98" (50-250 cm) in height, and 16-31" (40-80 cm) in diameter. The number of ribs varies from as few as 5 to 60, with spine groups of 8-10, each 1-1½" (3-4 cm) long. Spines are yellowish or reddish, darkening as they age. Multiple yellow flowers appear on the top of each cactus, each 1¾-2½" (5-7 cm) in diameter. Dry, oval-shaped fruits are 1¾-2½" (5-7 cm) long. The primary identifying feature is the large size.

References:

Anderson, Edward F., The Cactus Family, Timber Press, 2001, p. 228

Online References:

Echinocactus platyacanthus on Desert-tropicals.com

Echinocactus platyacanthus on Cactus Art: the World of Cacti & Succulents

Echinocactus platyacanthus on CactiGuide.com

Echinocactus karwinskii Zuccarini 1837

Echinocactus ingens Zuccarini ex Pfeiffer 1837

Echinocactus heliophorus Lemaire 1839

Echinocactus visnaga W. J. Hooker 1851

Echinocactus grandis Rose 1906

Echinocactus palmeri Rose 1909