Therophyte


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therophyte

[′ther·ə‚fīt]
(ecology)
An annual plant whose seed is the only overwintering structure.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Therophyte

 

an annual plant that survives unfavorable seasons—cold or dry seasons—in seed form. Most therophytes are of Mediterranean origin and are characteristic of deserts, semideserts, and southern steppes of the northern hemisphere, where they include many Cruciferae and Papaveraceae. In the forest zone therophytes are represented mainly by field weeds, for example, cornflower, pennycress, and stork’s-bill.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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The high percentage of therophytes in the present study may be related to the seasonal rainfall (Galal and Fahmy, 2012).
Chi-Square tests indicated significant differences in the percentages of chamaephytes, therophytes and phanerophytes species between the caatinga and the cerrado, and between the caatinga and the cerrado-caatinga transition areas.
Studies carried out in the caatinga region have demonstrated the predominance of therophytes over other life forms, at a proportion close to 40%, as underscored by Costa et al.
On the other hand, life form spectrum of grasses showed that therophyte was the dominant one followed by hemi-cryptophytes and phanerophytes.
(1) = Abundance; (2) = Life form; (3) = Leaf size; (4) = Habitat; (5) = Leaf appearance; A = abundance; Ch = Chamaephytes; Cm = Common; D = Dry; G = Geophytes; H = Hemicryptophytes; L = Leptophyll; M = Moist; Mac = Macrophyll; Mes = Mesophyll; Mic = Microphyll; N = Nanophyll; Re = Rare; S = simple; Th = Therophytes. Fig.
Geographic area Sites Species Medicinal species Eastern area 48 76 44 Western area 30 65 33 Middle area 1 10 1 Total 79 151 78 Table 6: Number of species in each life form for all species collected during the collection missions of Mediterranean coast of Libya during the spring and summer of 2009 and 2010 Life form Number of species % Trees 24 16 Phanerophyte (shrubs) 55 36 Chamaephyte (semi-shrubs) 11 7 Annual shrubs 4 3 Perennial forbs 24 16 Perennial grasses 17 11 Biennial forbs 2 1 Therophyte (annual forbs) 11 8 Climbers 3 2 Total 151 100 Table 7.
A therophyte from South America (Argentina, Brazil, Uruguay) (FREIRE & IHARLEGUI 1997: 29), Gamochaeta filaginea was known in the Iberian Peninsula from Caceres province only (GIRALDEZ FERNANDEZ & RICO HERNANDEZ, 1985).
The Trifolion cherleri represents submediterranean therophyte communities in the southern Balkans, classified in the Helianthemetalia guttati Br.-Bl.
The majority of taxa associated with Ageratina luciae-brauniae and/or Solidago albopilosa are phanerophytes (40%) or hemicryptophytes (36%); 2% are chamaephytes, 13% are cryptophytes, and 9% are therophytes. Forbs composed 33% of the taxa; trees were 22%, shrubs 10%, woody vines 5%, graminoids 15%, and ferns 15%.
The life form spectrum in Figure 2 shows that in the investigated areas the proportion of Therophytes (101 taxa) is higher than that of other life forms.
The biological types are: C chamaephyte, G geophyte, H hemicryptophyte, Hy hydrophyte, P phanerophyte, T therophyte. The pollination modes are: An anemophilous, En entomophilous, Hi hydrophilous.