The World Flora Online

Shrubs , deciduous, rhizomatous, aromatic. Leaves opposite, without stipules, petiolate. Leaf blade : margins entire or, on fast-growing shoots, occasionally with a few teeth. Inflorescences terminal on short, leafy branches of current growth, solitary flowers. Flowers bisexual. Hypanthium urn-shaped; tepals and stamens perigynous; inner tepals, stamens, and staminodes with succulent, white food bodies at tips. Tepals 15-30, fleshy, petaloid, spirally inserted on outside of hypanthium. Stamens 5-30, spirally inserted at top of hypanthium; staminodes 10-25, on inner surface of hypanthium; locules opening by longitudinal slits. Pistils 5-35, 1-carpellate, spirally inserted within hypanthium; ovules 2 per locule, distal ovule abortive, submarginal; style elongate, filiform; stigma dry, decurrent. Fruits achenes, 1-35, dark reddish brown, cylindric, pubescent, enclosed within enlarged, fibrous persistent hypanthium (pseudocarp). Seeds : endosperm absent.

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Shrubs or small trees, deciduous or evergreen. Branchlets dichotomous, quadrangular to subterete, with oil cells; buds covered with scales or naked and hidden [or not hidden] by base of petiole. Stipules absent. Leaves opposite, simple, petiolate; leaf blade pinnately veined, margin entire or subentire. Flowers bisexual, axillary or terminal on branchlets, usually solitary, radially symmetric, usually fragrant, generally appearing before leaves for deciduous taxa, undifferentiated into calyx and corolla but sometimes tepals of more than one form. Pedicel short. Tepals 15-27[-30], yellow, yellowish white, or white flushed pink [or brownish red], spirally arranged on outer surface of a cup-shaped or urceolate receptacle, shape variable, outer usually bractlike, inner petaloid. Stamens numerous, spirally inserted on apical surface of receptacle, in 2 series, outer series fertile, inner series aborted; fertile stamens spirally arranged; filaments short and free; anthers 2-locular, incumbent against connective, extrorse, dehiscing lengthwise by slits; connective exserted, apex apiculate; staminodes linear, linear-lanceolate, or oblong, pubescent or puberulous. Carpels few to numerous, distinct, spirally arranged on basal inner surfaces of hollow cuplike receptacle, 1-loculed; ovules 2 per carpel but usually 1 abortive, anatropous; styles filamentous and extended. Pseudocarp polygynaecial, fleshy when young but becoming dry and sometimes woody, composed of achenes contained within an expanded torus, apex with appendages from persistent staminodes. Achenes 1-seeded; endosperm little or absent; embryo large; cotyledons convolute, foliose.

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• 2
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Fls perfect, regular, perigynous, the hypanthium urceolate or campanulate; perianth of numerous (15–30) more or less petaloid tepals spirally arranged on the outside of the hypanthium; stamens 5–20, spirally arranged at the top of the hypanthium; filaments short or none; connective prolonged beyond the extrorse anther; 10–25 staminodes present internal to the stamens; pollen-grains dicolpate; pistils 5–35, distinct, spirally arranged within the hypanthium cup; style elongate, filiform, with decurrent stigma; ovules 2, but one abortive; achenes enclosed in the enlarged, fleshy hypanthium; embryo with 2 spirally twisted cotyledons; endosperm none; aromatic shrubs with opposite, simple, petiolate, entire, exstipulate lvs and solitary fls short-pedicelled at the end of short leafy branches. 3/5.

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• 5
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SELECTED REFERENCES

Nicely, K. A. 1965. A monographic study of the Calycanthaceae. Castanea 30: 38-81. Wood, C. E. Jr. 1958. The genera of the woody Ranales in the southeastern United States. J. Arnold Arbor. 39: 296-346.

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• 1
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