Revision of Nectandra (Lauraceae taxonomy) from Sat, 2015-07-04 05:49

General description: 

Evergreen trees or shrubs.  Terminal buds not perulate.

Leaves alternate or rarely opposite, penninerved.

Inflorescences thyrso-paniculate, rarely botryoid, not involucrate.

Flowers trimerous, bisexual, 3-17 mm in diameter.  Tepals 6, equal or the inner 3 slightly smaller, united at the very base (usually falling off as a ring after anthesis), papillose on the adaxial surface, usually brilliant white.  Fertile stamens 9, in 3 whorls, sessile or with distinct filaments, at least apically usually papillose, often with a triangular, sterile apex, the outer 6 equal, sometimes slightly adnate to the tepals, introrse, the inner three different in shape, with a pair of glands at the base, extrorse or latrorse.  Anthers 4-locular, pollen sacs arranged in a horizontal arc, rarely almost in two superposed pairs.  Staminodes of the fourth androecial whorl usually distinct, often apically glandular on adaxial side, at the base often united with the inner stamens, very rarely absent or completely united with the adjacent glands.  Receptacle flat to deeply urceolate.  Ovary free from the receptacle but often completely enclosed.  Fruit ellipsoid to globose, usually black or brownish purple at maturity, subtended by or partially enclosed in an often red receptacular cupule.

Throughout tropical and subtropical America.  About 120 species in the current circumscription.

Nectandra is usually recognized by perfectly rotate, brilliant white flowers, which are often large for the standards of Lauraceae (i.e., often ca. 1 cm or more in diameter).  The tepals are usually distinctly papillose on adaxial side, as if they were covered with frost.  After anthesis, they fall off as a ring, together with the stamens and staminodes.  The anthers are also very characteristic: their four pollen sacs are arranged in a shallow arc or almost in a horizontal row, and in many species the anthers are prolonged beyond the pollen sacs, forming a more or less triangular sterile tip.

Molecular analyses do not support Nectandra as monophyletic.  The Nectandra coriacea group may form a distinct evolutionary lineage, but so far the resolution and the support values in the Cinnamomeae are too low to reach any definite conclusions.

Further information:

Rohwer, J.G. 1993.  Lauraceae: Nectandra.  Flora Neotropica monograph 60.  New York, The New York Botanical Garden.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith