The spiny, thorny and prickly plants in the flora of Israel

Abstract

To examine whether spininess evolved at random or differently in various life forms and plant organs, we characterized spiny, thorny and prickly organs in the entire wild flora of Israel (294 such species). Of the species, 63.3% defended their reproductive organs (the most-defended organ) and 67.0% defended various non-reproductive organs. Ninety-three species defended both their reproductive organs and at least one other part; 48.3% defended their leaves and 36.4% their stems and branches. Spiny wings defended stems and branches only in herbaceous (annual or perennial) species. There were clear differences between the life forms. Annuals and perennial herbs defended mostly their reproductive organs (95.7 and 83.0%, respectively), dwarf shrubs defended mostly their leaves (54.2%) and shrubs and trees mostly their branches (89.7 and 76.2%, respectively). Trees do not defend their reproductive organs by associated sharp appendages. The differences in defence on various organs among different life forms may influence the results of meta-analysis studies of the optimal defence allocation if such differences are not taken into account. We noted spine, thorn and prickle colours for 167 species with yellow, red, orange and white being the dominant, supporting hypotheses about spines being visually aposematic.

Partly transparent young legume pods: Do they mimic caterpillars for defense and simultaneously enable better photosynthesis?

“…Trees in the flora of Israel do not defend their reproductive organs by associated sharp appendages. 17 Ronel and Lev-Yadun 17 proposed that there seems to be a simple evolutionary reason for these dramatic differences in allocation for defense and that the level of importance of seeds in survival selected the level of their defense. Annuals have no other means of genotype continuation, which is the reason for the fact that practically all spiny annual species defend their reproductive structures with spines or prickles.…”

Plant antiherbivore defenses in Fabaceae species of the Chaco

“…Physical defenses, as spinescence, play a more important role to protect stems and branches than reproductive organs (Ronel and Lev-Yadun, 2012). Among the features analyzed, it is worth highlighting that in spinescent species thorns color tends to be a cryptic character, i.e.…”

“…They include the following characters: spinescence, trichome types, and the color of thorns/spines compared to that of branches (Ronel and Lev-Yadun, 2012). Physical characters like spinescence and color of thorns were analyzed on field specimens, while trichome types on herbarium and field specimens.…”

Slug caterpillars ofParasa lepida(Cramer, 1799) (Lepidoptera: Limacodidae) become stuck on rose prickles

“…In addition to their antiherbivore role, these structures are also useful as climbing supports (Darwin 1865;Isnard & Silk 2009), as domatia for mutualistic defending ants (Janzen 1966(Janzen , 1974, for reducing solar irradiation (Mauseth 2006), for seed and vegetative dispersal (epizoochory) (Allen et al 1991, Bobich & Nobel 2001, etc. (Ronel & Lev-Yadun 2012 and references therein). Spines, thorns and prickles can mechanically wound mouths, digestive tracts and external body parts of large herbivores (Janzen & Martin 1982, Janzen 1986), but can also inject pathogenic bacteria and fungi into herbivores' bodies (Halpern et al 2007a, b).…”