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BIDENS PILOSA COMPLEX (ASTERACEAE) IN NORTH AND CENTRAL AMERICA
Author(s) -
Ballard Robert
Publication year - 1986
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1986.tb10891.x
Subject(s) - biology , asteraceae , achene , botany , taxon , bidens pilosa , sensu , chromosome number , white (mutation) , genus , chromosome , karyotype , biochemistry , gene
Field observations, chromosome counts, flavonoid chemistry, breeding system data, hybridization experiments, and a quantitative analysis of twelve morphological features combine to show that the North and Central American populations of B. pilosa sensu Sherff actually include three distinct species: B. odorata ( n = 12), B. alba ( n = 24), and B. pilosa ( n = 36). All these taxa are square‐stemmed, white‐rayed or discoid annuals with linear, obcompressed‐quadrangulate achenes, but each species can be distinguished morphologically by differences in ray length and width, in outer phyllary length, width and shape and chemically by differences in the chalcones accumulated in their leaves. New combinations are proposed and two varieties, B. odorata var. oaxacensis and B. odorata var. chilpancingensis , are described as new. Descriptions, distribution maps, synonymies, and a key to all taxa are provided.