Carduus Benedictus.
Fig. 4. Centaurea Benedicta. Linn. Blessed Thistle. The body of this seed is about twice as long as it is thick, is round and shaped much like a nine-pin, only instead of being small at the upper end, it has a stricture, from whence arises a beautiful crown of ten angles or points, out of which come also ten aristæ or spiculæ like ivory, about the length of the body of the seed, running taper upward, and set round in an uniform manner. Within the circle of these long spikes there are ten more, which are but very short, and of the same colour and consistence with the others. When these are all plucked off, the vestiges of the circles they form appear in the upper surface of the crown; in the middle of which a little process arises, but very superficially. That part which appears circular is white, and the rest of this surface, of the corona, of the same colour with the rest of the body of the seed, which is a sort of an olive-colour.
The body of the seed is of the sulcated kind, and looks exactly like a fluted pillar, and the surface shines as if varnished with some gummy substance.
At the lower or small end of this seed, there is an opening reaching up above a third of the length of the body of the seed, which discovers a white root, shaped like a cone at the bottom, and rising thicker by degrees till it divides into three limbs; these run taper upwards, till they are lost in the parenchyma of the seed, which at the place of their entrance appears somewhat fungous, but is more compact and clammy through its substance.
The length of the body is more than two eighths of an inch, and the aristæ exactly the same length. The corona is its umbilicus.
Plantago.
Fig. 5. P. Major. Linn. Plantain. By the imperfect idea we have of this seed from its minuteness, it may seem like a flea, as any small speck would, if a little oblong; yet its form is not constant, that is, there are scarce two of them precisely alike, some being perfectly elliptical, some with blunt angles, and some approaching a spheroid. They have a whitish mark on one side, which is the umbilicus of the seed, from whence the first rudiments of the plant spring, and the surface is entirely granulated over, and has a general appearance like some kinds of plumb-stones; the surface also shines a little, as if oiled or moist, and their colour is brown. One of the seeds cut transversely appears to have the shell or covering pretty strong in proportion to its size, which contains a parenchyma that is very porous and succulent. It is about a sixteenth part of an inch long, and a twenty-second broad.
Staphis Agria.
Fig. 6 and 7. Delphinum S. A. Linn. Stavesacre. The seeds of this plant are rough and angular, inclining to a triangle, although imperfectly so. They may be considered as having a basis or apex; the basis is thick and clumsy, and the apex runs to an angular point, which point is the umbilicus of the seed, out of which its first rudiments arise; it also has a convex and a plane or concave side; the former, Fig. 7, is rough, by reason of its being covered all over with porous cells, the ridges of which are also depressed or indented with rough pores, and granulated as if stuck full of sand. The concave surface, Fig. 6, is also rough, but not in the same manner, and so are the sides, which have a little flatness; these also are porous and sandy, and before the microscope, shine, and are coloured like dirty brown sugar-candy. The concave surface, notwithstanding the roughness, has one longitudinal ridge, and sometimes more, running from the basis to the apex, which has the same granulated surface with the rest. It contains a parenchyma, which is of a yellowish grey colour, and is moist and succulent.
This seed is in its natural size about two eighths of an inch long from its basis to the apex, and near as broad; however, some are broader in proportion to their length than others, and they are one eighth of an inch thick.