This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The habitat of this plant is moist shady places, swamps in woods. The habit is the rosette habit. The root is fibrous, oblique. The stem is wavy (hence the specific Latin name). There are few radical leaves, with lobes each side of a common stalk, the lower leaflets rounded, lobed, angled, toothed. The upper leaves have narrower lobes. There are no stipules. The flowers are white, with small erect petals, twice as long as the calyx. There are 6 stamens. The style is slender, long. The flower-stalks are at right angles, the pods erect. The plant is 6-12 in. in height. It flowers from April to September. It is perennial or biennial, or according to some annual, according to situation.
The habitat of this plant is cultivated fields and other similar ground. The plant has the rosette habit. It is intermediate between B. stricta and B. praecox. The stem is tall, with 2 or 3 angles. The lower leaves are ly-rate, the upper pair of lobes equalling the breadth of the heart-shaped to egg-shaped terminal lobe. The upper leaves are divided nearly to the base, with many lobes. The flowers are in a dense raceme. The petals are longer by twice than the sepals. The pods are erect, with a short, conical point, thick, short, angular, 4-6 times as long as the pedicels. The seeds are nearly as long as broad. The plant is 9-18 in. long, flowering from May to August, and is a herbaceous biennial.
The habitat of this plant is waste places, walls. The rootstock is woody. The plant is bushy. The stem is branched, leafy, smooth or hairy, bluish-green, foetid. The leaves are more or less smooth, bluish - green, linear to lance-shaped, acute, wavy, toothed, or deeply divided nearly to the base, the lobes narrow, unequal, linear, with distant teeth. The flowers are large, yellow, with inversely ovate, blunt, long-pointed petals, with a short claw. The pods are narrowed both ends, linear, distant, more or less erect, on long stalks, the valves flat. The style is stout, straight, and cylindrical. The seeds are in 2 rows. The plant is 1-2 ft. high, flowering between June and September, and is a herbaceous perennial.
Alyssum calycinum,L.( = A. alyssoides,L.). - The habitat of this plant is cultivated fields in the east counties on ploughed land, grassy commons in the south counties. The plant is herbaceous. The habit is prostrate, then ascending. The stem is branched below, stellately hoary or downy, rigid, ascending. The leaves are inversely ovate, oblong, lance-shaped, spoon-shaped, narrow below, few, scattered, blunt. The flowers are white or pale-yellow, then white, small, in racemes, lengthening in fruit. The sepals do not fall. The anther-stalks have no teeth. The shorter ones arise from between two bristle-like processes. The pods are numerous, downy, round, borne on short, stiff, spreading stalks, and are swollen, the margins broad, thin, and flat, notched above. There is a short style. The seeds are narrowly winged, there being 1-2 in each cell. The plant is 3-8 in. high, flowering from June to August, and is a herbaceous annual.