Each small unit is called a drupelet. In some, such as the blackberry, the flower receptacle is elongated and part of the ripe fruit, making the blackberry an aggregate-accessory fruit.
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Pyrenes extracted from a single fruit of Crataegus punctata A pyrene dissected to reveal the seed Pyrena or pyrene is the name for the stone within a drupe or drupelet. It consists of a seed surrounded by hard endocarp tissue.
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The fruit is drupaceous and fleshy, forming an aggregate. The fruiting carpel is indehiscent, commonly on a long, spirally twisted peduncle, with each drupelet becoming very long-stalked. The fruit contains one nonendospermic seed with starch. The embryo can be straight or slightly curved.
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OchnaLinnaeus C (1753) Sp. Pl. 1: 513. is a genus comprising 86 species of evergreen trees, shrubs and shrublets belonging to the family Ochnaceae. These species are native to tropical woodlands of Africa, the Mascarenes and Asia. Species of this genus are usually called ochnas, bird's-eye bushes or Mickey- mouse plants, a name derived from the shape of the drupelet fruit.
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The flowers are typically 5-merous with large, white petals and light green sepals, borne in mid-spring. Second-year plants are also capable of growing the fruit which gives the plant's common name, the blackberry. The fruits are compound drupes which change from bright red to black at maturity. Each section (drupelet) of a blackberry contains a single seed.
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However, mulberries, which closely resemble blackberries, are not aggregate fruit, but are multiple fruits, actually derived from bunches of catkins, each drupelet thus belonging to a different flower. Certain drupes occur in large clusters, as in the case of palm species, where a sizable array of drupes is found in a cluster. Examples of such large drupe clusters include dates, Jubaea chilensisC. Michael Hogan. 2008.
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The most likely cause of undeveloped ovules is inadequate pollinator visits. Even a small change in conditions, such as a rainy day or a day too hot for bees to work after early morning, can reduce the number of bee visits to the flower, thus reducing the quality of the fruit. Incomplete drupelet development can also be a symptom of exhausted reserves in the plant's roots or infection with a virus such as raspberry bushy dwarf virus.
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Diagram of a typical drupe (peach), showing both fruit and seed nectarine) type of peach (Prunus persica) over a -month period, from bud formation in early winter to fruit ripening in midsummer In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the pit, stone, or pyrene) of hardened endocarp with a seed (kernel) inside. These fruits usually develop from a single carpel, and mostly from flowers with superior ovaries (polypyrenous drupes are exceptions). The definitive characteristic of a drupe is that the hard, "lignified" stone (sometimes called "pit") is derived from the ovary wall of the flower. In an aggregate fruit, which is composed of small, individual drupes (such as a raspberry), each individual is termed a drupelet, and may together form an aggregate fruit.
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