This may explain its disastrous spreading. It is of course also possible that those parts which are not removed by cutting have a chance to set seed which makes new plants the next year. In which of these two ways Alfalfa Dodder is spreading in Canada is not yet known.
YELLOW LUCERNE (Medicago falcata L.)
Botanical description: Yellow Lucerne is closely related to Alfalfa. It is strongly perennial with a deep taproot and numerous stems. The stems are quite different from those of Alfalfa. They are seldom strictly upright, but are ascending or often even decumbent. They are more slender than the stems of Alfalfa and more woody, especially toward the base. The leaves are similar but generally have narrower leaflets. The flowers are in a cluster shaped like the inflorescence of Alfalfa but generally shorter and containing a smaller number of flowers. They are bright yellow and somewhat smaller than Alfalfa blossoms. The fruit is not twisted like that of Alfalfa but only slightly curved like a sickle—hence the name Sickle Medick, sometimes used by English writers.
Geographical distribution: Yellow Lucerne is indigenous to the Old World where it is rather common. It occurs in England, through western and central Europe, in southern and central Scandinavia and Russia, and in practically all parts of Asia north of the Himalayas.
Habitat and cultural conditions: It generally occurs in poor, sandy or gravelly soil and stands drought and severe cold better than Alfalfa; it is thus better suited to an adverse climate and a poor soil.
Agricultural value: It will never be as valuable as Alfalfa because of its decumbent or even creeping tendency and its comparatively low yield. It is a poor seed producer as a rule, the small quantity developed being considerably diminished by shattering.
Yellow Lucerne consists of a large number of different types which vary greatly in their mode of growth and are therefore of different agricultural value. As, however, they all have the above-mentioned drawbacks more or less pronounced, none of them, as far as is known at present, can compete with Alfalfa. In spite of this, Yellow Lucerne is of great agricultural importance, as will be readily understood from the description of Variegated Alfalfa.