Visiting Moorten Botanical Garden in Palm Springs is a step back in time, and worth the visit not just for the plants but the commentary from its gregarious, white-haired proprietor, Clark Moorten, who usually greets visitors at the entrance. This quirky, endearing garden is one of the last remnants of old Palm Springs, when there was time to watch little birds flit fearlessly among the thorns, marvel at a palm that grows sideways about 8 feet before it grows up and listen spellbound to Moorten’s wonderful and seemingly endless stories. The garden itself is small — roughly an acre of mature, artfully arranged cactuses and desert plants along shady dirt paths with hand-lettered signs, decaying desert artifacts and the famous “cactarium,” a word invented by Moorten’s mother, Patricia, who with his father, Chester “Slim” Moorten, began expanding the garden, established in 1938, after they bought the property in 1955. The cactarium, by the way, is a small weathered Quonset hut stuffed with weird and rare cactuses — some of which wind along the ground like …