The very glossy and richly deep green foliage seem to be so soft and luxuriant. Simple bright white flowers enhance the appeal. However, closer examination of Natal plum, Carissa macrocarpa, reveals impressively nasty thorn structures that are doubly branched into pairs of paired rigid and sharp thorns. That is four thorns each!
To make matters worse, all parts of Natal plum that are not fruit are toxic. But hey, they all work together to be visually appealing, even if really unfriendly. The one or two inch long evergreen leaves are quite round and stiff. The star shaped flowers that bloom as long as the weather is warm are somewhat fragrant in the evening.
Some varieties of Natal plum can reach the eaves, but most stay lower. They do not need much water, and can tolerate a bit of shade. The rosy red fruit would be delightfully colorful if it were not so rare. Manual pollination, preferably with a different pollinator, produces more of the two inch long berries that are something like mildly flavored cranberries.