The Other Side of Beekeeping
The Other Side of Beekeeping - May 2013
Some Wild Members of the Bean Family
The Genus Astragalus
Many species of Astragalus growing in North America have been described. By my count (2013) the USDA Plants website lists 426 species. In addition, it also lists numerous subspecies and varieties of these species. The differences between some of these species is most likely very small and it would take a specialist to be able to distinguish them all. The task would be beyond most of us, and often all that is recorded in the beekeeping literature is simply the genus “Astragalus.” The cases reported below represent some of those that are reported in the North American beekeeping literature.
Oertel, from his questionnaires, found the genus Astragalus to be important in ND, CO, IA, ID and TX. From their questionnaires, Ayers and Harman found the genus to be of some importance in CO, AZ, TX, and WY. The only species that Crane et al. mention in their ‘Directory of Important World Honey Sources’ is Astragalus sinicus (Chinese milkvetch), which they consider to have a high honey flow of 30 kg (~66 lbs) per colony.
Canadian milkvetch, milkvetch
Scientific name: Astragalus canadensis
Synonyms: Astragalus brevidens, Astragalus carolinianus, Astragalus halei, Astragalus mortonii (all apply to what are currently considered to be particular varieties of Astragalus canadensis).
Origin: North America and perhaps also into Central America. Gleason and Cronquist indicate that the species is found in Siberia. Perhaps it has a circumpolar origin. The distribution map provided by the USDA Plants Website, however, doesn’t show the species in Alaska.
Plant description: Astragalus canadensis is an erect, rhizomatous, usually robust perennial with stems to 150 cm (~4.9 ft) long. The lanceolate to deltoid stipules1 are fused (connate) and about 3 to 18 mm (~0.12 to 0.71 in) long. The leaves consist of 15 to 35 oblong or elliptic2 leaflets 1 to 4 cm (~0.39 to 1.57 in) long that are strigosebeneath with malpighian hairs.3
The inflorescences are racemes4 on relatively long 5 to 15 cm (1.97 to 5.9 in) peduncles5 that hold the spreading or downward bent, white, yellowish white or greenish cream colored 12 to 17 mm (0.05 to 0.67 in) flowers.
The 10 to 15 mm (~0.39 to 0.59 inch) pods are numerous, crowded, and erect, almost round in cross section, and have a prominent longitudinal ridge (keel) on the ventral surface. They are generally glabrous6, but infrequently are covered with short hairs.
Distribution: Gleason and Cronquist who deal with Northeastern U.S. and adjoining Canada, state that the species is found in open woods, on river-banks and shores, usually in moist soil. In Iowa, Pammel and King state that the species is common on black prairie soils and clay soils along borders of woods.
Blooming period: Gleason and Cronquist provide a blooming date range of June to August in the Northeastern parts of the U.S. and contiguous parts of Canada. Pammel and King provide a blooming date range of July and August for Iowa.
Importance as a honey plant: Pammel and King report observations made on A. canadensis on July 13, 1914, during which it was cloudy with a north wind. Insects working the plants included a fly, an ant, two bugs and a bee. The type of bee was unclear. A second set of observations was labeled only July 1914. During the second set of observations, one spike was visited during one hour by one fly, one ant, one bee (type unidentified) two bugs and a bumble bee. Despite the fact that the flowers had a pleasant odor, and the authors claim the nectar was “secreted in abundance”, they conclude that the species is not an important honey plant. Based on their admittedly limited observations, I would tend to agree, but there is no indication of either the size or flowering density of the observed patch.
chickpea milkvetch, cicer milkvetch, mountain chickpea, astragale pois chiche
Scientific name: Astragalus cicer
Plant description: Gleason and Cronquist describe the species as a diffuse leafy perennial with prostrate or weakly ascending stems 25 to 70 cm (~9.8 g to 27.6 inch) long. The stipules are connate7 in at least the middle and upper leaves and are lanceolate, narrowly pointed and usually bent downward.
The compound leaves usually contain 17 to 29, occasionally 31, lance-elliptic8 or oblong leaflets 0.5 to 3.5 cm (~0.20 to 1.4 in) long that are pubescent9 at least on the undersurface. The inflorescence stems (peduncles) are 4 to 11 cm (~1.6 to 4.3 in) long and are shorter than the leaf immediately beneath it.
The individual flowers are yellowish white or cream colored and 12 to16 mm (~0.47 to 0.63 in) long. The fruit is a hairy, short-stemmed, firm-walled, broadly ovoid or subglobose10 structure, 6 to 14 mm (~0.24 to 0.55 in) by 5 to 8 mm, occasionally 10 mm (~0.2 to 0.32 in, occasionally 0.39 in).
Distribution: Gleason and Cronquist indicate that the species has been “casually introduced” into disturbed moist places in the Western U.S. and has been more rarely established eastward. They indicate that for some reason the species has become especially common in Ingham county, Michigan. Rabeler and Crowder suggest that this is at least in part related to the Grand Trunk Western Railway, which runs through the Michigan State University campus. Voss agrees, stating that the species has been well established along the railroad since at least 1974 and that it has “doubtless escaped from cultivation”.
Blooming period: McGregor reports that the species blooms at Fort Collins, CO during June and July.
Importance as a honey plant: Ramsay in her book Plants for Beekeeping in Canada and Northern USA mentions Astragalus cicer and indicates that it is attractive to honey bees, “but (the) specific value is unknown”.
Additional Information: Ramsay notes that the species may be useful in irrigated and dry land areas as a soil improver or forage crop, but that it is not commonly cultivated in North America.