American Bee Journal • October 2016 Vol. 156 No. 10 • The Other Side Of Beekeeping

Historically there has been considerable controversy over the nectar production of lupines. This may at least be in part because some may produce nectar and others may not, or they may produce only very small amounts of nectar. It may also result from variations in observational technique used to provide an answer to the question. Below I provide a review of this question. The reader needs to be forewarned not to expect a final definitive answer. The first three references deal with a common topic, the structure of the staminal column, each reference adding a potential bit on insight into the question of nectar production. Beyond that, the remainder of the references are provided in the chronological order that they appear in the literature.

1926: John Lovell[9] seems to offer a way of distinguishing nectar-producing Lupinus species versus those that produce only pollen. He claims that in the nectariferous species, nine of the ten stamens of the flowers are united to form a tube, but that the tenth stamen remains free, allowing a bee to insert her tongue into the nearly closed-off tube by inserting it into the otherwise sealed tube on either side of the free stamen. In the species where all ten stamens are joined together they produce a closed cylinder and the bee cannot insert her tongue to obtain the nectar of the flower. Interestingly, while this seems such a reasonable explanation of at least some of the variation in the production of nectar by lupines, in the beekeeping literature, I found it mentioned only by Harvey Lovell[8] and Lawrence Goltz[5] in their honey production booklets (see below). The keys of Martin Wojciechowski[20] seem to indicate that John Lovell was correct about the variation in staminal structure and that it might therefore provide a partial answer to why there seems to be so much variation in the literature concerning lupine honey production. The Wojciechowski keys (group 3) found in the Jepson Manual (second edition) seem to indicate that at least in California, with the words “filaments of all stamens fused” (page 721) that in California all the native lupines have all of their ten stamens fused. If both this statement and John Lovell’s statements are correct, none of the California lupines should produce nectar. I have no verification of this, however.

1966: Harvey Lovell[8] adopts his father’s view and adds to it that in the case where all the stamens are joined together there are also no nectaries.

1977: The Lawrence Goltz[5] version of the Harvey Lovell publication repeats Lovell’s suppositions that some lupines have a closed staminal tubes and in these cases, there are also no nectaries. Primarily referring to the Texas blue bonnet (Lupinus subcarnosus) he seems to agree with the closed stamenal tube and no nectaries story. He goes on to say that while the distribution of Lupinus is general, they seem to be most common in Texas and surrounding states where bees collect pollen, but are rarely reported as collecting nectar. He then adds “In Oregon bees have been seen collecting nectar from L. nanus, L. albicaulis and L. laxiflorus (which) have (also1) been reported as pollen plants.” This seems to disagree with Burgett, Stringer and Johnson[2] who state “Bees are known to use L. bicolor as a nectar source and L. laxiflorus as (a) pollen source.”

1908: Sanborn and Scholl[16] writing about L. subcarnosus (one of the Texas bluebonnets) as a Texas bee forage state “honey yield good; also pollen of very bright and orange colors.”

1911: Richter[14] in one location places Lupinus affenis in the category honey plants not known to yield a surplus (presumably nectar) and in another section tells where in California the species grows, that it blooms January to April but seemingly contradicts the information in the first section, stating that there is “honey from the flowers.”

1921: Coleman[3]: In his pieced-together set of articles concerning California honey plants and writing apparently about L. albifrons says, “As a general thing, the Lupines are nectar producers, but on account of the deep flowers are only visited by bumblebees.” In this case (presumably L . Albifrons) and also a few other species, the flowers are small and, therefore, the nectar is available to honey bees.

1939: Oertel[11] from his extensive set of questionnaires reports the genus Lupinus and three species of Lupinus as having some importance in six states. There was no indication concerning whether the importance resulted from nectar and/or pollen production.

1941: Vansell and Eckert[19] indicate that apparently most of the lupines are not very attractive to bees. They indicate that while lupines are sometimes credited with a crop of honey, there is some doubt concerning the reliability of such reports. Certain species also supply a brownish-red pollen for bees. In their summarizing table under Lupinus sp. They label the values for both nectar and pollen as “questionable.”

1957: Milum [10] in his Illinois Honey and Pollen Plants mimeograph places Lupinus perennis (his only mention of the genus) into his group of Illinois plants producing pollen but little or no nectar.

1975: Robinson and Oertel[15] in their chapter ‘Sources of Nectar’ in the 1975 edition of The Hive and the Honey Bee separated North America into eight regions and indicated that lupines provided nectar in their Southern, Mountain, Southwestern, and Pacific regions.2 Interestingly, and to this author, incorrectly, Robinson and Oertel provided no indication that lupines provided pollen.

1978: Pellett[12] indicated that there was some controversy over whether lupines produce both nectar and pollen or only pollen. Using the name Lupinus subcarnosus (Texas bluebonnet) he indicates that the species is considered by some to provide nectar and also presumably pollen while others felt that it provided only pollen. In his review of the subject he Indicates that Von Mueller in his ‘Select Extra-Tropical Plants’ considered lupines to be among the most important sources of nectar and that “some, if not all lupines can be counted among (the) honey plants.” This author has been able to verify the latter quote From Von Mueller’s 1891 publication, but was unable to verify that Von Mueller considered “lupines to be counted among the most important sources of nectar.” The 1895 Von Mueller work I used was voluminous (654 pages) and perhaps I simply missed it. There appears to have been eight different editions of this title, so perhaps it was in another edition that Pellett found his information.

1979: Howes[6] writing about bee forage in the British Isles, regards most lupines as being nectarless. The lupines are in his opinion of “little account so far as the beekeeper is concerned.” He provides as a reference Knuth’s ‘Handbook of Flower Pollination’ 1906-1908.

1987: Ramsay[13] writing about Canadian bee forage generally considered the flowers of Lupinus to be nectarless and of little value to the beekeeper.

1989: Burgett, Stringer and Johnson[2] indicate that there are many Lupinus species in Oregon but they are rarely reported as honey sources. Bees are known to use L. bicolor as a source of nectar and L. Laxiflorus as a source of pollen.

1992: Ayers and Harman[1] from their questionnaires, found the genus to be of at least some importance in parts of Colorado, Arizona and in Canada, Prince Edward Island. In the breakdown of the responses concerning the relative importance of nectar and pollen, three responders indicated both nectar and pollen, one pollen and one with the use of question mark, possibly some nectar, and two, pollen only.

2012: Kirk and Howes[7] writing about lupines in the British Isles, under the heading ‘Honey’ provide a “NO”, suggesting that there is no honey produced by the lupines about which they are writing. For attractiveness to honey bees they rate it as a “2” on a 3 point scale. This seems to suggest that if there is nectar, there is not very much and that the major part of the attractiveness is probably for pollen.

Because of the inconclusiveness of the above, I made two telephone calls to individuals who had clearly made observations on bees working bluebonnets. My first telephone conversation was with Joe Marcus, the NPIN program coordinator at the Lady Bird Johnson Wildflower Center in AustinTexas. He indicated that he feels certain that the Texas bluebonnets do produce some nectar, perhaps just not large amounts of it. His evidence for that is that bees do come to the flowers but that the wildflower flora of the area is very diverse and the bluebonnets are not as attractive as some of the other wildflowers. The question then becomes could the bees be coming for only pollen? There is probably some nectar there based on the flowers’ attractiveness to some species of butterflies. He mentioned specifically a group of small butterflies called hair-streaks and perhaps some others as well . There would be no reason for them to come to the plants for pollen because they have no way of ingesting it. This suggests to him that the butterflies might be feeding on nectar produced by the lupine flowers but that it is small enough to not be of much interest to bees especially when the flora of the area is so rich with many of its members producing sufficient nectar to interest bees.

The second phone call was to Valerie Bugh who has a local reputation as a good naturalist. When she is making observations, she works extensively with a camera. She has taken thousands of photographs of insects that collect nectar on flowers including bluebonnets. Her photographs indicate that honey bees are the most common daytime feeders on bluebonnet flowers and when doing so, have their “face buried deep into the flowers.” Other daytime feeders that her photographs show include butterflies including the hairsteaks mentioned above and flies belonging to the family Syrphidae (syrphid flies). It seems a little odd to her that she doesn’t see more insects on the flowers because of their usual copious seed set. Because of the observed seed set, in addition to the insects mentioned above, she speculates that there are also nighttime feeders, most likely moths.

While I recognize that my two interviewees viewed the attractiveness of bluebonnet flowers to bees somewhat differently, my final conclusion is that the bluebonnets produce nectar, maybe even fair amounts of it. Concerning lupines in general: All I can say is that some probably produce nectar and others may not or only produce small amounts of it. Unfortunately I found no references in the beekeeping literature I searched that provided actual quantitative chemical analysis of nectar production within the lupines. Such literature may exist, but it would probably be in literature dealing primarily with plant physiology and biochemistry which, I did not search.

A number of plants in the Texas area in the genus Lupinus are generally referred to as bluebonnets. Apparently the shape of the blue petals are thought by some to resemble the bonnets worn by pioneer women to protect them from the sun, hence the name bluebonnet.

En mass, they are quite showy and in the spring can dominate the local landscape. It seems fitting that they should be selected as the Texas state flower. Over the years, however, there has been some political wrangling about which bluebonnet should be chosen for the honor. In 1901 the Texas state legislature declared the Texas State Flower to be Lupinus subcarnosus. There are, however, bluebonnet species in Texas which are bigger, bolder and more showy than that original choice. Most of the general public, however, not trained in the taxonomy of the group, was probably happy to simply call them all bluebonnets. In 1971 the Texas state legislature and the governor, probably not wishing to offend the Lupinus subcarnosus supporters, expanded the definition of the official state flower to include what were considered the Texas bluebonnets in general. The list currently includes: Lupinus subcarnosus, Lupinus texensis, Lupinus havardii, Lupinus concinnus and Lupinus plattensis. Today if you google ‘state flower of Texas’ you get a return of “Lupinus sp.”

Space prevents me from dealing with all the bluebonnet species. I have chosen to deal with Lupinus texensis largely because I was so impressed with the plantings of this species in the Lady Bird Johnson Wild Flower Center located in Austin TX. It currently seems to be the most common of the bluebonnet species, perhaps in part, because it is encouraged by the state highway department.

Plant description: Lupinus texensis is a winter annual that grows to about 60 cm (~ 24 in) in height. The stems bear long, soft, appressed or ascending straight hairs. The leaves have relatively long petioles (stems), are palmately compound with 4 to 7 lanceolate or oblanceolate3 leaflets that are essentially hairless on the upper surface and terminate somewhat bluntly or more or less pointedly. The flowers are distributed in erect terminal racemes4 with conspicuous white tips that result from whitish unexpanded hairy buds. The individual leaflike structures of the calyx5 are 6 to 8 mm (~ 0.24 to 0.31 in) long. The petals are almost always a deep blue but rarely may be white. The large upper petal initially has a white center that becomes purplish-reddish with age and possesses yellow-greenish spots. The wing petals are not inflated6, and when viewed from the front are nearly straight. The fruits are quite hairy and 2.5 to 4.2 cm (~0.98 to 1.6 in) long.[4] This species is often planted by The Texas Highway Department and is quite common in parts of Texas.

Blooming period: At the Lady Bird Johnson Wild Flower Center located in Austin, TX, the species generally starts blooming in mid- March with the peak bloom occurring in mid-April.

Importance as a honey plant: The bluebonnets appears to be at least a reasonably good honey plant though there may be better ones to be found in the area in which they grow. John Lovell[9] appears to think that the bluebonnets yield only pollen. This is also what his son Harvey Lovell[8] felt and also appears in the Lawrence Goltz[5] version of this work.. Sanborn and Scholl[16] in their bulletin ‘Texas Honey Plants’ say of Lupinus subcarnosus that the honey yield is good. Pellett[12], using Lupinus subcarnosus as an example of the bluebonnet group, indicates that some say that it yields only pollen, while Scholl (no reference provided but see the previous reference above) lists it as a source of honey.

Pollen: Clearly the bluebonnets produce pollen, but how important this is or could be to the area’s honey bees is unclear since there are large numbers of other attractive plants in the area.

Origin: Eastern North America Plant description: The sundial lupine is a bushy, many-stemmed, much-branched, hairy, erect perennial that can grow up to a meter (~39 in) in height but is more generally 2 ft or under.

The compound leaves have 7 to 11 leaflets radiating out from the main stem like the spokes of a wheel. They are narrow and oblanceolate7 to obovate, terminate in an abrupt tip, and have a continuous unbroken margin (no teeth or lobes etc.)

The flowers are about 1 cm (~0.39in) long and are generally blue or violet but rarely are pinkish or white and are borne on short floral stems (pedicels) in loose terminal racemes.8 The standard petals9 are nearly round with the sides turned back. The wing petals completely cover the curved keel (the lower two fused petals). The calyx10 is distinctly two-lipped and very hairy. There are 10 stamens where the filaments11 are united into a tube for about half their length. The pistil is solitary and the ovary is attached above the attachment point of the petals and calyx (superior ovary) and is covered with long soft silky hairs. The elongated portion of the pistil is capped by a terminal fringe (the stigma). The seed pods are 3 to 5 cm (~1.2 to 2.0 in) long and upon opening form coils.[17]

Distribution: See map. In Michigan the species is found mainly in open woods and clearings, usually in dry sandy soil.[17]

Importance as a honey plant: Oertel[11] from his questionnaires found Lupinus perennis to be of at least some importance in New Jersey. Ramsay[13] indicates that it is the most common species of the genus in Southern Ontario. In a review of the beekeeping literature, Lupinus perennis was found by Milum[10] to produce little or no nectar in IL. Oertel[11] from his questionnaires listed L. perennis as well as L. subcarnosus as being of some importance to beekeepers.

The author wishes to express his appreciation for the ability to view and photograph specimens in the Michigan State University Herbarium and also for the use of its library. He is especially appreciative of the considerable amount of time given to him by Alan Prather concerning the staminal situation in the lupines.

1. Ayers, G. S. and J. R. Harman. 1992. Bee Forage of North America and the Potential for Planting for Bees. In: The Hive and the Honey Bee (J. M. Graham, Ed.) Dadant and Sons. Hamilton IL.

2. Burgett , D. M. , B. A. Stringer and L. D. Johnston. 1989. Nectar and Pollen Plants of Oregon and the Pacific Northwest. Honey Stone Press. Blodgett, OR.

3. Coleman, G. A. 1921-1922. Beekeeping in our California National forests No.II. Honey flora. The Western Honey Bee. The article was published in parts February 1921 to January 1922. The material reorted on in this article was published August 1921, page 248.

4. Diggs, G. M., JR., B. L.Lipscomb, and R. J. O’kennon. 1999. Ilustrated Flora of North Central Texas. Botanical Research Institute of Texas. Fort Worth, TX.

5\ Goltz, L. R. 1977. Honey Plants. A revised edition of the original Honey Plants Manual of Harvey Lovell. Pub. By Rev. Ed. Pub. Gleanings in Bee Culture, Medina, OH.

7. Kirk W. D. J. and F. N. Howes 2012. Plants For Bees. A Guide to the Plants that Benefit the Bees of the British Isles. International Bee Research Association. Cardiff, United Kingdom.

8. Lovell, H. 1966. Honey Plants Manual. A Practical Field Handbook for Identifying Honey Flora. The A. I. Root Co.

10. Milum, V. G. 1957. Illinois Honey and Pollen Plants. Contribution from the Departmentj of Horticultue, University of Illinois, Urbana, Illinois.

11. Oertel, E. 1939. Honey and Pollen Plants of the United States. U. S. D. A. Circular 554. U. S. Government Printing Office. Washington, D. C.

13. Ramsay, J. 1987. Plants for Beekeeping in Canada and the Northern USA. International Bee Research Association. London.

14. Richter, M. C. 1911. Honey Plants of California, College of Agriculture, Agricultural Experiment station. Berkeley, CA.

15. Robinson, F. A. and E. Oertel. 1975. Sources of Nectar and Pollen. In the 1975 Edition of The Hive and the Honey Bee. Dadant and Sons. Hamilton, IL.

16. Sanborn, C. E. and E. E. Scholl. 1908. Texas Honey Plants. Texas Agricultural Experiment Stations Bulletin 102.

17. Smith, H. V. 1966. Michigan Wildflowers. Cranbrook Institute of Science. Bloomfield Hills, Mi.

18. USDA, NRCS. 2016. The PLANTS Database (http://plants. Usda.gov, 26 June 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA.

19. Vansell, G. H. and J. E. Eckert. 1941. Nectar and Pollen Plants of California. Bulletin 517. University of California. Berkeley, CA.

20. Wojciechowski, M. F. 2012. Fabaceae (Leguminosae) Legume family. In The Jepson Manual (Second Edition). Bruce G. Baldwin Convening Editor. University of California Press. Berkeley, CA.