Chondrodendron
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Authority
Barneby, Rupert C. & Krukoff, Boris A. 1971. Supplementary notes on American Menispermaceae. VIII. A generic survey of the American Tricilisisae and Anomospermeae. Mem. New York Bot. Gard. 22: 1-89.
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Family
Menispermaceae
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Scientific Name
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Description
Genus Description - Inflorescences usually fasciculate on knotty spurs from old wood, cymose-paniculate, the [female] simpler and fewer-flowered than the [male], sometimes subracemose. Flower [male]: sepals 12 or more, in several strongly graduated cycles, the outermost minute, the 6-12 innermost distally glabrate, membranous, and petaloid, their tips at full anthesis rotately spreading and finally subdeflexed; petals 6, membranous, much shorter than the inner sepals; androecium 3-6-merous, in typical species of 6 separate filaments abruptly dilated distally, incurved through ± 90° just below the anthers and the connective prolonged beyond them as a stout appendage, the anther-sacs tilted forward through 90° and therefore appearing horizontally dehiscent, in one species (C. microphyllum) the androecium reduced to a 3-merous columnar syandrium bearing at apex a ring of 6 erect anther-sacs, the connective narrow and unappendaged; flower [female]: sepals and petals of the [male]; carpels 6; style simple, subulate; torus becoming subglobose, not dilated into ray-like carpophores; drupe (unknown in C. microphyllum) oblong-ovoid, contracted at base into a stipe up to 1/4 the length of the body; exocarp mealy-coriaceous, when dry black, thinly minutely puberulent when young, glabrate in age; mesocarp almost 0, the exocarp therefore fitting closely over and cleanly peeling from the endocarp; endocarp inversely U-shaped, turned abruptly on itself over a vertical, transverse condyle issuing from the base, the testa chartaceous, traversed around its long curve with many subparallel, ± anastomosing fibers, smooth within; embryo clothed in a hyaline seed-coat, of 2 parallel, equal, appressed cotyledons of dense, brittle-bony texture joined at their distal apex by a minute radicle; no endosperm. — Leaves beneath densely and minutely white-felted, the individual trichomes not appearing separate to the naked eye; blades severalnerved from the petiole, often incipiently peltate and with undulately crenulate margins, the costa giving rise to more than 1 pair of major incurved-ascending secondaries, the first of which arises below middle of the blade. — Spp. 3, one sub-Andean on the headwaters of the Amazon, extending north to Panama, the other 2 on the southeast margins of the Brazihan central plateau. — Generitype: C. tomentosum Ruiz & Pavon.
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Discussion
Detandra Miers, Contr. Bot. 3: 18, 364. 1871.
Because we here restrict the scope of Chondrodendron to include only those three species characterized by many-seriate sepals and (so far as known) a stipitate drupe deciduous from a globose torus, we present a revised generic description. When the drupe of C. microphyllum is discovered, the position of that species, which differs from the rest in its trimerous synandrium, will require revision. We follow tradition in disposing of it as an anomalous Chondrodendron, of which it has the staminate perianth and general facies, although the leaf-blades are generally plane and not undulately crisped around the margins. If it proves distinct, the monotypic genus Detandra Miers can be revived for it. Segregation of the 6-sepalate Chondrodendrons as a new genus Curarea is discussed under the next, where the differences in fruit-structure are considered in greater detail.