This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The flowers are pale-yellow (hence the first part of the English name), in paired and crowded terminal heads, tinged with purple. The bracts equal the calyx, and the keel is acute (hence the generic name, from the Greek). The pods are finely hairy, with six or more joints, netted, and imperfectly 2-celled.
This plant is dwarf, at most 6 in. The flowers appear in June and July. The plant is perennial.
The flower is conspicuous, yellow and purple, with a tubular calyx, and a general arrangement of parts much as in Lotus, but the petals have long claws or stalks, the carina or keel is erect and has a recurved tooth at the tip, and the upper tenth stamen is free for insertion of the insect's proboscis. The stigma is minute, and the ovule is stalkless.
Seeds of this plant are dispersed by the plant's own mechanism. The pod is 2-celled, and by contraction the seeds are thrown from it to short distances by an explosive motion.
Being a rock plant, this plant grows on a rock soil derived from older barren schistose or granitic rocks.
A beetle, Coccinella 22-punctata, a moth, Xylina conspicillaris, and a fly, Cecidomyia giraudi, feed on the plant.
The name Oxytropis is from the Greek, oxys, sharp, tropis, keel, in allusion to the narrow keel. The second Latin name refers to the habitat, in fields.
Essential Specific Characters:85. Oxytropis campestris, D.C. - Stem woody, leaflets lanceolate, leaves as long as flower-stalks, erect, downy, flowers yellow, purplish, pods hairy.
Yellow Mountain Oxytropis (Oxytropis Campestris)
Sainfoin (Onobrychis Viciaefolia, Scop.)
The distribution of this plant in the North Temperate Zone is West and S. Europe and Northern Asia, and it is unknown before this period in early beds. In Great Britain it is found in Somerset, Wilts, Dorset, Hants, and in the Thames district; it is absent from S. Kent, but occurs throughout Anglia except in Hunts, and not in West Gloucestershire, Monmouth, or Stafford, in the Severn district; in Wales it is found only in Glamorgan, and elsewhere is introduced. Watson regards it as doubtfully indigenous in Mid and S.-E. England, and it is usually a relic of cultivation. It is a plant of hilly, rocky ground, and is a feature of the south country and the eastern counties, dispersed by farming operations, but as a fodder plant turns up, or is likely to do so, wherever quarrying is in progress.
The stems are long, suberect, rather rigid, with numerous leaves, with leaflets each side of a common stalk, consisting of 3-12 oblong or linear lance-shaped leaflets, shortly stalked, and with a blunt point, entire, practically smooth, dark-green, with an odd or terminal one.
The flowers are in close racemes, rose-red, with dark veins. The tube of the calyx is silky, and it is short with awl-like teeth. The wings of the flowers are very short. The pods are dark-brown, netted, rough, roughly semicircular, downy, and contain one seed.
The Sainfoin grows to a height of 18 in. It flowers during June, July, and August. It is a most beautiful perennial which is quite worthy of cultivation by the horticulturist.
The flower resembles those of Melilotus and Trifolium repens, but in the Sainfoin the carina or keel does what the alae or wings did with it in the latter case, springing back after being pressed down. The alae are reduced and just cover the claw of the carina, not allowing the removal of honey laterally. The insect settles on the carina, which is a lever for downward rotation, and its elasticity causes it later to recoil. The stigma is prominent and when the flower is visited by a bee it touches the bee's abdomen, in older flowers protruding 1 1/2 mm. beyond the carina. Cross-pollination is accomplished, the flowers being attractive, and the calyx tube is short (2-3 mm.). The vexillum is broad and ascends obliquely, being a fulcrum or lever for the bee's head when pushing back the carina with its legs. Honey and pollen are both accessible to short-lipped bees. The visitors are Hymenoptera (Apidae), Diptera(Syrphidae); Lepidoptera, Green-veined White Butterfly (Pteris napi), Lycaena, Zygoma, Euclidia glyphica, Plusia gamma.
The pod is winged and crested, spiny, and may be dispersed by aid of the wind or animals, or merely by dehiscence or falling when ripe. Sainfoin is a chalk plant indulging in a lime soil, and found also on oolitic rock soils, or where fodder has been grown, where it may, when on cold clay soil, etc, persist for a short period.
Photo. H. Irving - Sainfoin (Onobrychis Viciaefolia, Scop.)
The fungi, Rhytisma onobrychidis, Ramularia onobrychidis, Sainfoin leaf-spot, infest it, and it is galled by Cecidomyia onobrychidis', whilst a beetle, Bruchus canus, also lives on it.
Onobrychis, Dioscorides, is from the Greek, onos, ass, and brucho, bray, the animal being said to bray for it. The specific name viciae-folia means vetch-leaved.
Sainfoin is from the French, sain, wholesome, foin, hay. Cinque-foil, Cock's-comb, Cock's-head, Lasting Grass, Meadow Fatch, Medick Fitch, French Grass, Hen's Bill, Lucerne are the only names.
To expatiate on the value of this plant a pamphlet was published upon it in 1671, when it was spelt Saint Foine. It was said to be found among the herbs and grass in the manger where our Lord was born. It suddenly opened its flower to form a wreath around His head. This gave rise to the practice of decking mangers at Christmas with moss, sowthistle, cypress, and holly. It was introduced into this country as a fodder plant in the seventeenth century from the Continent, where it had lone been cultivated, and excellent hay is made from it.
Essential Specific Characters:88. Onobrychis viciaefolia, Scop. - Stem tall, erect, leaves paired, pinnate, leaflets entire, 12-15; flowers crimson, in a raceme, with pink and white lines, on long peduncles, calyx woolly, pod twice as long as the latter.