Echinocereus viridiflorus is the green-flowered hedgehog cactus of the US Great Plains and intermountain west, the northernmost Echinocereus, with small lemon-scented green flowers and exceptional cold-hardiness to −20°C dry. Cactaceae.
Echinocereus triglochidiatus is the claret cup hedgehog of the US Southwest and northern Mexico, a clumping cactus with scarlet hummingbird-pollinated flowers and exceptional cold hardiness. Cactaceae.
Echinocereus knippelianus is the soft-bodied dwarf hedgehog of the Coahuila and Nuevo Leon limestone grasslands, with weak spination, dark green skin, and magenta flowers near the crown. Cactaceae.
Echinocereus rigidissimus is the rainbow hedgehog cactus of the Sonoran borderlands, with dense pectinate radial spines that band ruby through pink to white as they age and large rose-pink flowers. Cactaceae.
Echinocereus pectinatus is the comb-spined hedgehog cactus of the central Mexican Plateau, with flat pectinate radials in pink-banded rows and large magenta funnel flowers in late spring. Cactaceae.
Pseudolithos caput-viperae forms multi-stemmed clumps from roughly 12 months, a freely branching habit rare in the genus. Native to northeastern Somalia. Apocynaceae, not Cactaceae.
The most recently described species in the genus (2001), Pseudolithos mccoyi grows on Tertiary limestone along the Dhofar coast of Oman and adjacent southern Yemen. Freely-branching quadrangular stems form small finger-like clumps unlike any other member of the genus. Described in Asklepios 82 by Lavranos & Mies.
Type species of the genus Pseudolithos and the rounded pebble mimic of NE Somalia; the stone-mimicking milkweed that anchors every Pseudolithos collection. Cultivation notes, CITES status, and seed-grown care for the easiest stapeliad in the genus.
Pseudolithos cubiformis is a cube-shaped stapeliad endemic to northeastern Somalia. Body geometry, carrion-scented flowers, stone-mimicry ecology, and the temperature-gated cultivation regime that keeps seed-grown plants alive in collections.
Gymnocalycium mihanovichii f. rubra is the chlorophyll-free moon cactus behind the global Hibotan trade, an obligate graft that cannot photosynthesize and survives only on a green rootstock. Commercially released by Eiji Watanabe in 1948, it is now among the most widely sold cacti in the world, with South Korea producing roughly 70 percent of global supply. CITES Appendix II with Annotation #608 exempting grafted colour mutants on approved rootstocks from permit requirements.
