Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

Classification of the Euphorbiaceae

Grady L. Webster
Annals of the Missouri Botanical Garden
Vol. 81, No. 1 (1994), pp. 3-32
DOI: 10.2307/2399908
Stable URL: http://www.jstor.org/stable/2399908
Page Count: 30
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
Classification of the Euphorbiaceae
Preview not available

Abstract

The family Euphorbiaceae appears to be monophyletic, despite proposals for segregate families. The Euphorbiaceae display a great variety of growth forms, including at least 17 "models" of Halle. Anatomical characters particularly useful for classification include wood structure, laticifer type, trichomes, and stomata. Inflorescences are basically dichasial, and pseudanthia have evolved several times. Pollen nuclear number and exine structure provide useful criteria for characterizing genera, tribes, and subfamilies. Structure of the seed coat is characteristic for the family and does not provide evidence for a polyphyletic origin of the family. Pollination is prevailingly entomophilous, and seed dispersal by ants is important in many taxa. Geographic distribution patterns of genera show a concentration of primitive taxa in Africa and Madagascar, although in subfamily Crotonoideae there is evidence of a neotropical center. Disjunctions between Africa and South America are common. Bentham's hypothesis of an Old World origin of the family appears well supported. The basic distribution patterns appear to reflect early (Cretaceous and Paleogene) dispersal across land or narrow water barriers and spectacular but rather trivial instances of long-distance dispersal in the late Tertiary and Pleistocene; Tertiary high-latitude dispersals via the Bering land bridge appear to have been relatively insignificant.

Page Thumbnails

  • Thumbnail: Page 
[3]
    [3]
  • Thumbnail: Page 
4
    4
  • Thumbnail: Page 
5
    5
  • Thumbnail: Page 
6
    6
  • Thumbnail: Page 
7
    7
  • Thumbnail: Page 
8
    8
  • Thumbnail: Page 
9
    9
  • Thumbnail: Page 
10
    10
  • Thumbnail: Page 
11
    11
  • Thumbnail: Page 
12
    12
  • Thumbnail: Page 
13
    13
  • Thumbnail: Page 
14
    14
  • Thumbnail: Page 
15
    15
  • Thumbnail: Page 
16
    16
  • Thumbnail: Page 
17
    17
  • Thumbnail: Page 
18
    18
  • Thumbnail: Page 
19
    19
  • Thumbnail: Page 
20
    20
  • Thumbnail: Page 
21
    21
  • Thumbnail: Page 
22
    22
  • Thumbnail: Page 
23
    23
  • Thumbnail: Page 
24
    24
  • Thumbnail: Page 
25
    25
  • Thumbnail: Page 
26
    26
  • Thumbnail: Page 
27
    27
  • Thumbnail: Page 
28
    28
  • Thumbnail: Page 
29
    29
  • Thumbnail: Page 
30
    30
  • Thumbnail: Page 
31
    31
  • Thumbnail: Page 
32
    32