Eastern Santa Cruz County's Virtual Community Meeting Place
The Patagonia Pollinator Notebook is a 'work in progress' and still in an experimental phase. It is meant to be a resource for identifying common flowers in the Sonoita Creek watershed and learning about their pollinators. The notebook will feature photos and accounts of the common pollinator plants in our region, giving information on species identification, flowering time, and pollination biology of each species. There are a few example species accounts shown below.
If people find the notebook useful, new species accounts will be added and there will be an interactive component to allow participants to comment and add information about plant locations and flowering dates. If there is no interest, the notebook will be discontinued but if it proves to be useful to those wanting more information about local pollinator plants, it will be continued and will grow to include accounts of most or all of the nectar producing plants in our area.
Agastache Giant Hyssop or Horse Mint
If (alas!) I had to pick just one plant for my pollinator garden, it would be Agastache rupestris. This southern Arizona native flowers profusely from June to October. The anbundant, long (20-30 mm), thin, rose-purple flowers attact hummingbirds (see photo), bees, moths, and butterfies. The plants my garden grow to 3 feet high and almost three feet diameter. What more could you ask of a plant.
There are six species of Agastache in our area, three of which occur in the Santa Cruz drainage. Agastache Wrightii has short (3-5 mm) rose-colored flowers and occurs mostly north (Pima county and northern Santa Cruz county) and East (Chochise County) of Patagonia. A. Barberi is the most widespread of the local species and is the only Agastach known to grow in the Patagonia mountains. It has long rose-purple flowers like A. rupestris but rupestris has long linear leaves and those of Barberi are more triangular (deltoid).
Hummingbird visiting Agastache rupestris
Among the visitors to Agastache rupestris are carpenter bees (Xylocopa spp.). These large, black bees are too big to reach the nectar through the corolla tube, so they bite a hole into the base of the flower and "steal" the nectar- I say steal because they take the nectar but do not pollinate the plant. In my garden, I have seen hummingbirds visit flowers already pierced by a carpenter bee and, you guessed it, the hummingbirds take the easy route, also stealing the nectar.
Kallstroemia grandiflora or Arizona poppy
There is no better place to start than with Kallstroemia grandiflora, the plant that has put a golden glow on our hillsides for the past month. Known as Arizona poppy, Kallestroemia is in the Zygophyllacae or caltrop family, the same family as creosote bush, Larrea tridentate.
Kallestroemia is pollinated by bees but is capable of self-pollination when no bees visit it. M. Osorio-Beristain and colleagues at the Universidad Nacional Autónoma de México studied pollination efficiency in this species in northern Mexico to determine if native or exotic bees were more effective pollinators. They found that the Africanized honey bee transfers 2.5 times less pollen per visit than the native bee Trigona nigra. But the honey bees visited the flowers 2.65 times more frequently so that overall exotic bees and native bees appear to be equally efficient pollinators.
Amoreuxia palmatifida or Mexican yellowshow
Only a few plants flowering in late summer in Patgonia can easily be confused with Kallestroemia granidifora. One of them is Amoreuxia palmatifida, sometimes called Mexican yellowshow. Though superficially similar, the two species are not closely related and can be easily distinguished by their leaves. Kallestroemia has compound leaves that look rather like pea leaves, but, as the name implies, Amoreuxia palmatifida has palmate leaves, as can be seen in the photo below.
Amoreuxia are visited by bees but are reported to produce no nectar, so the only reward for a visitor is pollen. Both Amoreuxia and Kallestroemia fold up their flowers as darkness approaches. This is common in bee-visited plants and is thought to prevent nectar robbing by night visitors. But remember Amoreuxia produces no nectar, making this explanation dubious.
The fruit is a large, 3-celled capsule said to have been used by native Americans for food, as were the roots. However, another name for this plant is “throw-up flower,” suggesting at least some parts are distasteful.
Ipomea hederacea and Ipomea coccinea
Ipomea is the morning glory genus. Two species, I. hederacea (shown below) and I. coccinea, are common, but indeed glorious, sights on late August and September mornings in the Patagonia area. Besides being strikingly beautiful, one brilliant blue and the other scarlet red, together they afford us a chance to ask the question, “Are pollinator syndromes real?”
In order to reach the nectar of some flowers, pollinators have to probe or even crawl into a corolla, a long “whorl” or tube made of fused petals. Ever since Darwin’s time, evolutionary biologists have argued that flowers with long, thin, red corollas attract hummingbirds as pollinators and that plants with blue flowers, especially those with wide, “open mouth” corollas, are adapted to attract bees.
Recently Wolfe and Sowell studied four species of morning glories (2006 International Journal of Plant Sciences 167: 1169-1175) to see if Ipomea species with strikingly different floral morphologies attracted different kinds of pollinators as predicted. Ipomea hederacea and I. trichocarpa fit the ‘‘bee’’ syndrome -- they produce blue and purple flowers that have large corolla openings and they secrete small volumes of concentrated nectar. The other two, I. quamoclit and I. hederifolia (both very similar to I. coccinea) have the ‘‘bird’’ syndrome – they secrete a large volume of dilute nectar and have long red flowers with narrow, tubular corollas. The local pollinator fauna consisted of 11 species of Lepidoptera (butterflies), several species of bees, and one hummingbird species.
They found that the hummingbirds fed only on the red flowered I. hederifolia and I. quamoclit and that bumblebees foraged exclusively on the blue-flowered I. hederacea and I. trichocarpa. Other bees and butterflies were common flower visitors but they showed little to no preference for flowers of one type or the other. The authors concluded their article by stating “the Ipomoea species tended to be quite specialized in their use of pollinators… (the) results support the notion that pollination syndromes do aid in partitioning the pollinator fauna.”
Of course, one study, by itself, does not prove or disprove that pollinator syndromes are real. If you are still not convinced, test it out for yourself. Ipomea hederifolia and I. coccinea are both relatively common around Patagonia. Keep an eye out for them and record the pollinators you see visiting them. Let us know what you find out by writing a note in the comments section below.