In Pinus the only leaves produced on the main stern and the lateral shoots are scales, the acicular leaves of the tree growing from axillary shoots.
Sammetblende or przibramite is a variety, from Przibram in Bohemia, consisting of delicate acicular or capillary crystals arranged in radiating groups with a velvety surface and yellow colour.
Tungsten disulphide, W52, is obtained as soft black acicular crystals by the action of sulphur, sulphuretted hydrogen or carbon bisulphide on tungsten.
Quinine of commerce is the neutral sulphate,C20H24N202 H2S04.8H20, which occurs in commerce in the form of very light slender white acicular crystals.
It crystallizes in white or pale fawn-coloured acicular prisms or silky needles, and is soluble in alcohol and ether, and in loo parts of cold and 3 of boiling water; it is without odour and has an astringent and an acid taste and reaction.
As found in nature, saltpetre generally forms aggregates of delicate acicular crystals, and sometimes silky tufts; distinctly developed crystals are not found in nature.
The haematoidin pigment may vary in colour from yellowish or orange-red to a ruby-red, and forms granular masses, rhombic prisms or acicular crystals.
These are, according to Meyer, acicular crystals, which he calls tricizites.
Elongated, cylindrical, rounded at both ends; thick cuticle with acicular spicules; radula polystichous or wanting.
It is the methyl ester of a neutral body colchicein, which may be obtained in white acicular crystals.