Arecaceae (Palmae)

Arecidae: Arecales. The Arecaceae are woody shrubs, vines, or trees comprising about 200 genera and 3,000 species that are further characterized by having large or very large leaves, each with a tubular sheathing base that typically splits open on one side at maturity. The leaves are alternate, petiolate, and palmately or pinnately cleft to once or twice compound. The inflorescence is usually paniculate and is typically subtended by one or more bracts or spathes that may become woody at maturity. The flowers are actinomorphic, generally small, and are bisexual or more often unisexual. The perianth usually consists of two whorls of 3 distinct or connate segments each, often distinguished primarily by size, the outer series or calyx being the smaller. The androecium consists typically of 6 distinct stamens in two whorls of 3 each but sometimes comprises up to several hundred variously connate or adnate stamens. The gynoecium is syncarpous or apocarpous. Syncarpous forms consist of a single compound pistil of usually 3 carpels, 1 or 3 styles, and a superior ovary with 3 locules, each containing a single basal, axile, or apical ovule. Apocarpous, forms consist of usually 3 simple pistils, each with a superior ovary containing one locule with a single basal to apical ovule. The fruit is usually a drupe.

Each "thumbnail" image below is linked to a larger photograph.

Cocos nucifera, coconut palm or niu. This is an example of a feather palm with pinnately compound leaves. Several inflorescences of various ages can be seen, each associated with a woody bract or cymba. The large flower buds with overlapping perianth at the top of the upper right photo are female. The smaller, more numerous flowers with the valvate corollas are male. Careful attention to the unopened male flowers will reveal the very short calyx lobes at the base of the larger, valvate petals. Seedlings are illustrated in the lower right photo.
Arecaceae, unknown species. These flowers appear to be functionally male with six stamens and a rudimentary gynoecium.
Arecaceae, unknown species. These flowers have a well-developed, apparently apocarpous gynoecium, and appear to be functionally female.
Roystonea regia, royal palm.
Metroxylon amicarum, ivory nut palm.
Pritchardia martii, loulu hiwa. This is an endemic Hawaiian fan palm with palmately cleft leaves.

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