Allelopathy

Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy) or detrimental (negative allelopathy) effects on the target organisms.

Allelopathy is characteristic of certain plants, algae, bacteria, coral, and fungi.  Allelopathic interactions are an important factor in determining species distribution and abundance within plant communities, and are also thought to be important in the success of many invasive plants.

List of allelopathic plants

Shrubs

Adenostoma fasciculatum ( chamise )

Allaiaria petiolate ( garlic mustard )

Artemisia californica ( California sagebrush )

Asparatus officinalis ( asparagus )

Bassia scoparia ( burning bush )

Centaurea maculosa ( spotted knapweed )

Chromolaena odorata ( Siam weed )

Cyperus rotundus ( nut grass )

Encelia farinose ( brittlebush )

Forsythia spp

Helianthus annuus ( sunflower )

Lantana camara ( bunga tahi ayam )

Rhododendron spp

Salvia leucophylla ( purple sage )

Sambucus spp ( elderberry )

Solidago spp ( goldenrod )

Trees

Ailanthus altissima ( tree of heaven )

Arctostaphylos uva-ursi ( Manzanita )

Casaurina equistifolia ( rhu pantai )

Delonix regia ( red flame )

Eucalyptus spp

Juglans nigra ( black walnut )

Pinus spp ( pines )

Prunus laurocersus ( cherry laurel )

Crops

Avena spp ( oats )

Coffea Arabica ( coffee )

Hordeum vulgare ( barley )

Nicotina tabacum ( tabacco )

Oryza sativa ( rice )

Secale cereal ( rye )

Triticum aestivum ( wheat )

In the wilder area, oaks have little growing underneath..this was a eerie, foggy morning.

Casuarina equisetifolia litter completely suppresses germination of understory plants as shown here despite the relative openness of the canopy and ample rainfall (120 cmyr) at the location

 Eucalyptus have rather suppressed other vegetation spp. through allelopathic affect

Manzanita ‘circle’ can be easily seen and means “Don’t plant here!”