Yarrow Broomrape (Orobanche Arenaria, Borkh.)

This plant is parasitical upon Achillea Millefolium, which grows in fields and by the wayside. The stem is simple and leafless. The corolla is tubular, curved in front, the tube flattened at the back in the central part, the throat expanded, glandular on the outside, the lobes of the lip blunt, with edges bent back. The tubular calyx is glandular, downy, has 5 sepals, with awl-like teeth. The stigma is nearly 2-lobed, the style glandular. The smooth filaments have hairs below. The side bracts are awl-like, the intermediate ones lance-shaped, narrow above. The plant is 12-18 in. high, flowering in July and August, and is perennial, parasitic, never green, but brown.

Knapweed Broomrape (Orobanche Elatior, Sutton)

The habitat of this saprophytic parasite is that of the host-plants Centaurea Scabiosa, Knautia arvensis, Carduus lanceolatus, meadows and pastures, roadsides, and waste places. The stem is erect, yellow, the bracts not so long as the corolla, which is glandular outside, curved, tubular, flattened at the side above, the upper lip 2-lobed, toothed, the lobes bent inwards. It is at first rose-yellow, then pale or dull. The sepals are divided into two nearly to the base, glandular, hairy all over, as long as the tube. The stigma is 2-lobed, yellow, and the anthers white when dry. The anther - stalks are slender below, smooth above. The plant is 9-24 in. in height, flowering from June to August, and is perennial.

Clove-scented Broomrape(Orobanchecaryophyll-acea, Sm.). - The habitat of this plant is that of the host-plants Galium Mollugo, G. verum, and Rubus fruticosus. The habit is erect, the stem brown, the flower more or less bell-shaped, or tubular, curved on the back, the sepals divided into two nearly to the base, shorter than the tube, the 3 lobes of the lower lip nearly equal, wavy and toothed, the upper 2-lobed. The stamens are inserted above the base of the tube, which is hairy below, glandular above. The stigma is purple, with 2 lobes nearly separate. The plant is 6-12 in. in height, and flowers between May and July, being perennial.

Common Broomrape (Orobanche Minor, Sm.)

The habitat of this plant is that of the host-plants Clover and Crepis virens. The stem is erect, yellowish-brown or purple, slender, the corolla yellowish-white, with violet or black veins, the tube narrow in the middle, the sepals many-veined, the tube erect or curved downwards, the limb white or yellow, the lobes of the upper lip spreading, the lower toothed, nearly equal, wavy. The stigma is purple, bilobed, the lobes hardly connected, the anthers yellow when dry. The stamens are inserted below the middle of the tube, smooth, with scattered hairs, below the style also smooth, with only a few hairs anteriorly. The plant is 6-24 in. high, flowering from June till August, and is annual.

Purple Broomrape (Orobanchepurpurea, Jacq.)

The habitat of this plant is grassy pastures, where the host-plants, Achillea Millefolium, etc. grow. The habit is erect, the stem blue-purple, tough, not swollen below, downy, like the scales, bracts, calyx, and corolla. There are 3 bracts. The calyx is bell-shaped, with 4 teeth or lobes, which are shorter than the tube, lance-shaped or triangular. The tube is curved, the lobes of the lips acute, the upper lip 2-lobed, the lobes pale-blue with darker veins. The stigma is white, hardly divided, the anther-stalks smooth. The middle of the tube is narrow. The capsule has the valves free above. The plant is 4-12 in. in height, and flowers in June and July, being-perennial.

Picris Orobanche (Orobanche Picridis, F. Schulze)

This is a native plant, with a predilection for Picris hieracioides and Crepis as host-plants, being- found in disused quarries and elsewhere. The habit is erect, the stem slender, hairy, glandular, the plant very pale. The corolla is erect or at right angles afterwards, the bracts white with purple veins, 1-nerved. The sepals are entire, slightly curved at each end, the corolla nearly straight, and the upper lips of the corolla are not notched but have the tip bent in. The stigma is purple, the lobes touching, the stamens hairy below within, and inserted below the middle of the corolla-tube. The anthers are pale-purple, brown, or yellow. The plant is 6-18 in. in height, flowers from June to August, and is perennial.

Ivy Broomrape (Orobanche Hederae, Duby)

This plant is parasitic on the Ivy, and found in the habitat of the latter in woods and fields, in hedgerows, etc. The habit is erect, the stem purplish. The corolla is violet-brown, the sepals i-veined, the spike loose, the upper lip egg-shaped, entire, folded, notched, the corolla bent, the middle lobe of the lower lip longest, the lobes of the stigma partly attached, yellow, the anthers brown, paler when dry, the stamens inserted below the middle of the tube, smooth, with hairs below, the style with hairs above, purple-tinged. The plant is 6-24 in. in height, and is in flower between July and August, being a perennial.

Yellow Broomrape (Orobanche Ritro, Gren. And Godr.)

This plant is found where Cat's Tail grows in pastures, etc. The habit is erect. The flowers are yellow, the corolla hairy and very glandular, like the whole of the plant, and downy. It is 4-9 in. in height, and flowers in June and July, being a perennial.