Although the precise toxicity mechanism is unknown, calcium oxalate crystals (raphides) and protease in the idioblast
of the plant are considered to be the causes.
A--Aligned colleters several in the stipules base; B--Three colleter aligned (C); D--Detail of stipular colleter (C); E--Dry Secretion (SE) in stipules (S); E--Stipule idioblast
with raphides (R) on stipule; F--Raphides on stipule with (R).
Mature raphid and raphid idioblast
structure in plants of the edible aroid genera Colocasia, Alocasia and Xanthosoma.
The spongy parenchyma also presented idioblasts
with druses (Figures 2A and 2D-E).
Cote GG (2009) Diversity and distribution of idioblasts
producing oxalate crystals in Dieffenbachia seguine (Araceae).
Calcium deposition in idioblasts
of mulberry leaves.
Mesophyll (Figure 3E) consists of spongy and palisade parenchyma, and often contains druse idioblasts
. As in the cotyledons, the midrib also has only one collateral vascular bundle.
Qualitatively evaluated were the following: (1) idioblasts
; (2) epidermic cells; (3) cuticle; (4) form of the stomata; (5) arrangement of the stomata; (6) form of the guard cells; (7) subsidiary cells; (8) hypodennis; (9) trichomes; (10) mesophyll; (11) vascular and extravascular fibers; (12) vascular bundles; and (13) fungi.
In Plant kingdom, oxalate is a common photosynthetic byproduct (2) and many plants are known to synthesize calcium oxalate crystals which are stored in leaves and organ cells like idioblasts
The midrib and secondary veins of damaged and control leaves characteristically feature druses in the parenchyma and idioblasts
with tannins (Figure 4U, V).
with raphids immersed in pectic matrix (Fig.