Fruit drupe attached to the receptacle. In some bramble fruits (such as blackberry) the receptacle is elongated and part of the ripe fruit, making the blackberry an "aggregate-accessory" fruit. The strawberry is also an aggregate-accessory fruit, only one in which the seeds are contained in achenes. In all these examples, the fruit develops from a single flower with numerous pistils. A multiple fruit is one formed from a cluster of flowers (called an "inflorescence"). Each flower produces a fruit, but these mature into a single mass. Examples are the pineapple, fig, mulberry, osage-orange, and breadfruit. In the photograph on the right,
Boletellus ananas the trunks of the tropical tree "Dicymbe corymbosa" (subfamily Caesalpinioideae), associated with ectomycorrhizas within humic accumulations. It is rarely found fruiting on the ground on heavily decayed, root-penetrated wood. Rolf Singer suggested that the fungus was not mycorrhizal, noting that as well as occurring under or on the bases of both pine and oaks, it occurred in scanty humus and debris accumulated on rock walls. Singer concluded that the species prefers to grow on hard surfaces. Harry D. Thiers, in his study of the bolete flora of Texas, wrote that "B. ananas" was a rare species that often fruited abundantly