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 meadows, pastures, waste places, hedgerows, moist places, and thickets. The habit is erect, the stem rigid, ribbed, with few branches. The plant is smooth or downy. The leaves are shining, linear lance-shaped, with few small coarse teeth, stalkless, and distant. The flowerheads are few, in corymbs, with white florets, those of the disk greenish-white, tubular, bisexual, those of the ray white, 8-12. The fruit is smooth, shining, without pappus. The plant is 1-2 ft. in height. It flowers later than Milfoil, and has larger flower-heads. Sneezewort is a herbaceous perennial.
St. James's Ragwort (Senecio Jacobcea, L.). - The habitat of this plant is pastures, roadsides, waste ground, sand dunes, etc. The habit is erect. The stem is tall, smooth, finely furrowed, rarely cottony, with numerous leaves. The radical leaves are lyrate, divided nearly to the base, with lobes larger towards the extremity, but the terminal one in this case smallest, toothed, the upper clasping, sessile or stalkless, the lower oblong, stalked. The flowerheads are in large corymbs, erect, with spreading rays, yeliow, the fruit of the disk having pappus, that of the ray being smooth. The plant is 1-4 ft. in height, and flowers between June and September, being a herbaceous perennial.
The habitat of this plant is dry fields and pastures, and sandy heaths. The habit is erect. The stem is cottony, stout, branched, with corymbose heads, purplish or yellow. The radical leaves are lance-shaped, spreading, armed with spines, green above, cottony below. The stem-leaves are half-clasping, shorter, numerous. The flowers are purple, the heads many, the corollas all tubular. The outer involucral bracts are divided nearly to the base, and fringed with hairs; the inner are white and linear. The whole plant is spinous, the spines serving as an adaptation to dry-soil conditions and as a protection from cattle and creeping insects. The fruit is brown, silky, with hairs divided into two nearly to the base. The pappus is in 1 row, feathery, united into groups of 3 or 4 at the base. The plant is 6 in. to 1 1/2 ft., and flowers in July till October, being a biennial and herbaceous.
The habitat of this plant is wet meadows, ditches, and moist woods. The habit is erect. The stem is solitary, soft, stout, slightly branched, with many wavy spines, winged. The leaves are spinous, lance-shaped, running down the stem, deeply divided to the base, the lobes 2-3-fid, the segments narrow-pointed, hairy both sides, cottony below. The heads are in terminal, small, leafy clusters, the florets dark-purple or white. The involucre is cottony, ovoid, crowded. The phyllaries are ovate to lance-shaped, closely pressed, the outer blunt-pointed, the inner narrow-pointed, purplish-green. The fruit is pale, narrow, smooth, with a dirty-white pappus. The plant is 2-4 ft. high, flowering between July and September, and is a herbaceous perennial.