Of the CaOx crystals in plants, five forms have been recognised (Franceschi and Homer 1980)--crystal sand, raphide
, druse, styloid and prismatic.
Idioblasts containing raphides
along the leaf margin region are common (Fig.
The precise assignation of Epilobium species was based on tri-chome and raphides
morphology (Krajsek et al.
Bischoff describes the unique way in which the toxin in these plants works: "These plants contain pointy crystals called raphides
in packets within the cells called idioblasts.
Idioblasts with raphides
in the storage parenchyma and chlorenchyma.
Typical shapes are square (cr), slate-needle (raphides
), globular (druses; dr).
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 it remains inedible until the scaly covering dries and falls away.
Crystals have been classified as crystal sand, druses, raphides
, styloid, and prism .
2001) and the Cannaceae, Costaceae, Marantaceae and Zingiberaceae families would represent a unique clade, based on characters such as reduction of androecia to an only functional stamen, large and conspicuous staminodia, seeds with perisperm, absence of raphides
in parenchymatic tissues and entire, firm and not torn leaves (Judd et al.
Starch granules and raphides
identified as possibly from the aroid Colocasia esculenta (taro) have been found on the surfaces of undecorated Lapita potsherds from Anir, New Ireland (Crowther 2005).
Crystalline inclusions in leaf tissue: (0) absent; (1) sandy; (2) druses; (3) raphides
, as well as other forms; (4) framboids.
What does it do: Friar's Cowl, like most members of the Aracaceae, contains Calcium oxalates, known as raphides
, which are tiny, needle like crystals that cause severe irritation on contact with the eyes and mucous membranes, and in some cases where the juice has been ingested will cause the tongue to swell dramatically, that can in rare cases, lead to suffocation.