The pulp within a cactus fruit contains hundreds to thousands of seeds. Unfortunately, very few of these seeds will ever germinate, and probably less than 0.1 percent of these seed will ever grow to mature plants. Life is just too dangerous and for the seed and young plants. The first problem a cactus seed faces is also a blessing. The succulent flesh of a cactus fruit is like a magnet during the bitterly dry and hot summer. Birds and animals gorge themselves on these fruits as a rich source of moisture and nutrients. As they eat the fruit though, many, if not most of the seeds are also eaten. This isn't such a bad thing, as long as the seeds are not crushed by chewing. The seeds are especially adapted to remaining intact and passing directly through the digestive tract unharmed. With most cactus fruit being brightly colored and located high on the plant, these fruits are especially enticing to birds, which may be the only organisms capable of reaching the fruits on taller cacti. For example, the saguaro cactus holds its fruits tens of feet off of the ground, only allowing birds to access it. Being birds do not chew food, instead swallowing it whole by the beak-full, most of the seeds can pass through the digestive tract unharmed and be deposited in their fecal matter. Kind of a disgusting start to life but true never-the-less.
|Young Saguaro Cactus growing under the canopy of a Palo Verde.|