Of the CaOx crystals in plants, five forms have been recognised (Franceschi and Homer 1980)--crystal sand, raphide
, druse, styloid and prismatic.
Prostratin, colorless raphide
, was prepared from the roots of Euphorbia fischeriana which were collected in Heilongjiang Province, China and the voucher specimen (No.
Elongate, multicellular raphide
sacs form parallel rows in all organs investigated.
Artefact Starch Raphide
'Cooked' Charred number granule size lengths starch interior range ([micro]m) ([micro] m) granules on residue interior 47 1-5 20-30 [check] 56 1-4 10-20 [check] [check] 58 1-5 20-30 59 1-5 10-30 60 1-5 10-20 84 1-4 10-20 [check] [check] 95 1-4 20-31 * 96 1-5 25-50 [check] [check] 99 1-6 14-28 [check] * 2.4 1-4 15-35 [check] 2.5 1-5 10-45 [check] 2.6 1-5 10-20 2.7 1-5 15-35 2.8 1-4 20-45 2.9 1-5 15-32 [check] * 2.10 1-5 20-40 2.11 1-6 22-45 2.13 1-4 10-30 [check] 2.14 1-5 10-20 2.15 1-5 20-30 [check] * * Denotes ambiguous residue.
The identification is based on starch grain and xylem vessel morphology, and raphide
Among all crystal types, raphide
bundles and their enclosing cells present the largest variation in this or any other family and have been subject to more intensive study (Keating, in press a).
The fruits resemble Indian Maize and develop in a sheath; as they ripen they exude an aroma of Jackfruit but because the sheath contains Calcium Oxalates in the form of needle-like crystals (Raphides
) that will lodge in the throat and gums.
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.
(ST = stomata; SC = substomatal chamber; M = mesophyll; AdE = adaxial epidermis; AbE = abaxial epidermis; X = xylem; P = phloem; BPF = bundle of phloematic fibers; BXF = bundle of xylem fibers; Hi = hipodermis; R = raphides
; OC = ornamented cuticle).
In terms of microscopic identification, Dendrobium officinale could be identified by vascular bundle sheath observed under the fluorescence microscopy and the distribution of raphides
under normal light microscopy .