SHARP-EATMAN
NATURE
PHOTOGRAPHY
National Butterfly Center
IMPORTANT POLLINATOR PLANTS OF THE LOWER RIO GRANDE VALLEY
& The Bees That Pollinate Them
Below is a shortlist of 42 pollinator plants that are essential to maintaining a diversity of bee species at the National Butterfly Center. Most are native to the Lower Rio Grande Valley. Notably, some of the NBC plants most important to wild bees are fairly humble "weeds" allowed to sprout undisturbed -- scrub mallows like Rio Grande abutilon and spiked malvastrum; unobtrusive groundcovers like frog fruit and erect spiderling; and self-seeding wildflowers like silverleaf nightshade, common sunflower, Texas snout bean and alamo vine.
Native bees divide into two groups: "generalists" that forage on a broad array of plants, and "specialists" that feed on a particular plant genus or family. A diverse wild bee population requires a mix of plants that sustain both generalist and specialist bees. At the NBC, mallows, cacti and aster-family flowers serve as important food sources for specialist bees. Essential generalist bee plants include many native flowering shrubs that are well-established in NBC gardens for the benefit of butterflies. Chief among these are crucita, shrubby blue salvia, whitebrush, wax mallow, scarletbush, Berlandier's fiddlewood and guayacan. Intermingled with these are regionally common native trees that appeal to bees that forage on pea-family flora, among them ebony, retama, tenaza, huisache and honey mesquite.
Aster-family plants with long bloom periods -- daisies, blanket flowers, resinbush, Mexican hat and hierba del marrano -- are also key food sources for generalist bees at the NBC. Ornamentals with long bloom periods such as esperanza and golden dewdrops, both native to the neighboring Mexican state of Tamaulipas, serve the pivotal function of maintaining generalist bee populations during periods of flower scarcity caused by drought or unseasonable cold snaps.
Pollinator - Plant Associations
Abutilon hypoleucum
Common Name: Rio Grande Abutilon
Plant Family: Malvaceae
Associated Bee Species
Aztec cuckoo leafcutter bee (Coelioxys azteca)
Honey-footed exomalopsis
(Exomalopsis mellipes)
Honey-tailed agapostemon
(Agapostemon melliventris)
Snow's exomalopsis (Exomalopsis snowi)
Notes: This native plant begins blooming in June. It is a primary attractor of leafcutters, cuckoo leafcutters, and Exomalopsis.
Aloysia gratissima
Common Name: Whitebrush
Plant Family: Verbenaceae
Associated Bee Species:
Worthy long-horned bee (Florilegus condignus)
Ringed exomalopsis (Exomalopsis anillis)
Slosson's sand-dwelling cuckoo Leafcutter
(Coelioxys slossoni arenicola)
Snow's exomalopsis (Exomalopsis snowi)
Zaptlana leafcutter (Megachile Zaptlana)
Notes: In the Lower Rio Grande Valley generally, this plant is a key attractor of the rare Texas mesoxaea (Mesoxaea texana) and glorious protoxaea (Protoxaea gloriosa). Whitebush is also visited by a spectrum of other native bees, including Agapostemon (striped sweat bees), Anthophorula, leafcutters, cuckoo leafcutters, Exomalopsis, and Florilegus long-horned bees.
(Anisacanthus quadrifidus var. wrightii)
Common Name: Flame acanthus
Plant Family: Ericaceae
Associated Bee Species:
Aztec sweat bee (Augochlora azteca)
Griswold's carpenter bee (Xylocopa griswoldi)
Parkinsonia carpenter bee
(Xylocopa tabaniformis parkinsoniae)
Southern carpenter bee (Xylocopa micans)
Notes: At the NBC, flame acanthus (also called Wright's desert honeysuckle) is a favorite of multiple species of carpenter bees.
Arctostaphylos glauca
Common Name: Big berry manzanita
Plant Family: Ericaceae
Associated Bee Species:
Black-footed oil-digger bee
(Centris atripes)
California digger bee
(Anthophora californica)
Notes: This plant is a great attractor of centris and digger bees during its bloom period in April. Rarely seen through most of the year, black-footed oil-digger bees mob big berry manzanita in such large numbers in mid-April that the manzanita seems to buzz with life when you walk by it.
Argemone aenea
Common Name: Golden prickly poppy
Plant Family: Papaveraceae
Associated Bee Species:
Golden green sweat bee
(Augochlora aurifera)
Lasioglossum (Dialictus) metallic sweat bee
Littoral cactus wood-borer bee
(Lithurgopsis littoralis)
Rincon chimney bee (Diadasia rinconis)
Silver-tailed petal-cutter (Megachile montivaga)
Notes: Golden prickly poppies provide pollen for chimney bees, sweat bees and cactus wood-borer bees in late March and early April. Male chimney bees and wood-borer bees sleep in the poppies and seek refuge in them during bad weather. Silver-tailed petal-cutter bees trim off pieces of the poppies' delicate petals and use them to line their nests.
Argemone sanguinea
Common Name: Red prickly poppy
Plant Family: Papaveraceae
Associated Bee Species:
Compact Anthophorula (Anthophorula
compactula)
Lasioglossum (Dialictus) metallic sweat bee
Little prickly pear long-horned bee
(Melissodes opuntiellus)
Littoral cactus wood-borer bee
(lithurgopsis littoralis)
Rincon chimney bee (Diadasia rinconis)
Notes: Like the golden prickly poppies shown above, red prickly poppies provide pollen for chimney bees and cactus wood-borer bees in late March and early April. Male chimney bees, long-horned bees, Anthophorula and wood-borer bees sleep in the poppies and seek refuge in them during bad weather.
Bidens alba
Common Name: Romerillo
Plant Family: Asteraceae
Associated Bee Species:
Aztec cuckoo leafcutter (Coelioxys azteca)
Heriades resin bee (Heriades variolosa)
Honey-footed exomalopsis
(Exomalopsis mellipes)
Ligated furrow bee (Halictus ligatus)
Similar Exomalopsis (Exomalopsis similis)
Notes: Bidens alba attracts a multitude of small bee species during the fall. It is one of two plants on which the rare Aztec cuckoo leafcutter has been found at the NBC.
Boerhavia erecta
Common Name: Erect spiderling
Plant Family: Nyctaginaceae
Associated Bee Species:
Green metallic bee (Augochloropsis metallica)
Notes: This dainty and easily-overlooked native plant is a favorite of sweat bees on NBC grounds. It grows in untended areas along the borders of the front gardens.
Chromolaena odorata
Common Name: Crucita
Plant family: Asteraceae
Associated Bee Species:
Golden-green sweat bee (Augochlora aurifera)
Honey-footed exomalopsis (E. mellipes)
Honey-tailed agapostemon (A. melliventris)
Ringed exomalopsis (Exomalopsis anilis)
Shining oil-digger bee (Centris nitida)
Singular cuckoo bee (Leiopodus singularis)
Snow's exomalopsis (Exomalopsis snowi)
Notes: Crucita blooms throughout the fall at the NBC. In late November, after most plants have succumbed to cold, crucita serves as the most reliable food source for many NBC generalist bee species.
Crucita is one of the few plants at the NBC on which the very uncommon singular cucoo bee (Leiopodus singularis) has appeared.
Citharexylum berlandieri
Common Name: Berlandier's fiddlewood
Plant Family: Verbenaceae
Associated Bee Species:
California digger bee (Anthophora californica)
Four-banded nomia (Nomia tetrazonata)
Honey-tailed agapostemon
(Agapostemon melliventris)
Notes: During the fall (Sept. - Nov.) this plant is the principal source of pollen and nectar at the NBC for the honey-tailed agapostemon. Berlandier's fiddlewood is also an important food source for spring bees. It is the only spring plant at NBC on which the four-banded nomia has been spotted.
Croton humilis
Common Name: Low croton
Plant Family: Euphorbiaceae
Associated Bee Species:
Birkmann's cellophane bee (Colletes birkmanni)
Chichimeca leafcutter bee (Megachile
chichimeca)
Snow's exomalopsis (Exomalopsis snowi)
Zaptlana leafcutter bee (Megachile zaptlana)
Notes: This plant is an important pollen source at the NBC for the Chichimeca leafcutter and Birkmann's cellophane bee.
Duranta erecta
Common Name: Golden dewdrops
Plant Family: Verbenaceae
Associated Bee Species:
Black-footed oil-digger bee (Centris atripes)
California digger bee (Anthophora californica)
Capistrata digger bee (Anthophora capistrata)
Tepanec long-horned bee (Melissodes tepaneca)
Worthy long-horned bee (Florilegus condignus)
Notes: This verbena-family plant is a key or sole pollen source for a variety of generalist bees during the fall at the NBC. Without this steadfast hardy bloomer at hand, the bee species listed here would struggle for survival at the NBC during periods of unusual autumn drought or cold.
Duranta erecta is native to Tamaulipas, the Mexican state directly south of the National Butterfly Center.
Ebenopsis ebano
Common Name: Ebony tree
Plant Family: Fabaceae
Associated Bee Species:
Chichimeca leafcutter (Megachile chichimeca)
Honey-footed exomalopsis (E. mellipes)
Western honey bee (Apis mellifera)
Notes: Texas ebony blooms in June and July at the NBC, when its flowers are mobbed by honey bees. This tree also attracts leafcutters and Exomalopsis.
Gaillardia pulchella
Common Name: Blanketflower
Plant family: Asteraceae
Associated Bee Species:
American bumble bee (Bombus pensylvanicus)
Ligated furrow bee (Halictus ligatus)
Parallel leafcutter bee (Megachile parallela)
Red-faced triepeolus cuckoo bee
(Triepeolus rufoclypeus)
Notes: This is one of the preferred plants at the NBC for the endangered American bumble bee.
Guaiacum angustifolium
Common Name: Guayacan
Plant Family: Zygophyllaceae
Associated Bee Species:
California digger bee (Anthophora californica)
Parkinsonia carpenter bee
(Xylocopa tabaniformis parkinsoniae)
Western honey bee (Apis mellifera)
Notes: This singular plant,
a hardwood evergreen native
to the Lower Rio Grande Valley,
is an important pollen source in
early spring (February-March), when
few plants are in bloom. It attracts
bees of multiple genera. Guayacan
is a member of the same plant
family as creosote bush.
Hamelia patens
Common Name: Scarletbush
Plant Family: Rubiaceae
Associated Bee Species:
Strand's carpenter bee (Xylocopa strandi)
Notes: During the fall at the NBC, firebush is an essential food for Strand's carpenter bee, a species found within the U.S. only in southern Texas.
Havardia pallens
Common Name: Tenaza tree
Plant Family: Fabaceae
Associated Bee Species:
Common little leafcutter bee
(Megachile brevis)
Western honey bee (Apis mellifera)
Notes: When tenaza trees bloom in June and July at the NBC, they are mobbed by honey bees and by common little leafcutter bees.
Helianthus annuus
Common Name: Common sunflower
Plant family: Asteraceae
Associated Bee Species:
Scaly cuckoo leafcutter bee (Coelioxys editus)
Ligated furrow bee (Halictus ligatus)
Sunflower chimney bee (Diadasia enavata)
Tepanec long-horned bee
(Melissodes tepaneca)
Texas agapostemon (Agapostemon texanus)
Triepeolus rufoclypeus cuckoo bee
(Triepeolus rufoclypeus)
Notes: At the NBC, large stands of common sunflowers sustain a multitude of wild bee species. Many of these are species that show a preference for aster-family plants.
The common sunflower is the only plant on which the sunflower chimney bee,
the Texas agapostemon and the Coelioxys edita cuckoo leafcutter bee have been documented at the NBC.
Leucophyllum frutescens
Common Name: Cenizo, Texas sage
Plant family: Scrophulariaceae
Associated Bee Species:
Birkmann's exomalopsis
(Exomalopsis birkmanni)
Honey-footed exomalopsis Exomalopsis mellipes)
Honey-tailed agapostemon (A. melliventris)
Andrena (Opandrena)
Notes: Texas sage is a documented pollen source for Exomalopsis, mining bees and sweat bees. In fall, 2018, this plant was visited by the generalist pollinator known as the honey-footed Exomalopsis. This beautiful wild bee rarely appears within the U.S. outside of south Texas.
Malpighia emarginata
Common Name: Barbados cherry
Plant family: Malpighiaceae
Associated Bee Species:
Black-footed oil-digger bee
(Centris atripes)
Shining oil-digger bee (Centris nitida)
Notes: Bees of the genus Centris use the oils from Malpighia to line the walls of their nest chambers. In early May, these bees can be seen buzzing happily through the Barbados cherry in large numbers.
Malvastrum americanum
var. Americanum
Common Name: Spiked Malvastrum
Plant Family: Malvaceae
Associated Bee Species:
Golden green sweat bee (Augochlora aurifera)
Ochraceous chimney bee (Diadasia ochracea)
Portly long-horned bee (Melisoptila pinguis)
Tropical chimney bee (Diadasia tropicalis)
Notes: At NBC, this plant is essential to the survival of the rare Messiloptila pinguis long-horned bee. In early November 2019, hundreds of female Melissoptila pinguis appeared on a single stand of Malvastrum americanum. The plant opens its flowers in late afternoon; thus pollinators arrive to feed on it at that time as well.
Malvaviscus arboreus var. drummondii
Common Name: Wax mallow, Turk's cap
Plant Family: Malvaceae
Associated Bee Species:
Griswold's carpenter bee (Xylocopa griswoldi)
Strand's carpenter bee (Xylocopa strandi)
Notes: Wax mallow is a principal food source for carpenter bees at the NBC.
Melochia tomentosa
Common Name: Teabush
Plant Family: Malvaceae
Associated Bee Species:
California digger bee (Anthophora californica)
Worthy long-horned bee (Florilegus condignus)
Globe mallow bee (Diadasia diminuta)
Little prickly pear long-horned bee
(Melissodes opuntiellus)
Mason bee (Osmia sp.)
Tepanec long-horned bee (Melissodes tepaneca)
Tropical chimney bee (Diadasia tropicalis)
Notes: Teabush sustains a broad array of bee genera in April at the NBC.
Merremia dissecta
Common Name: Alamo vine
Plant Family: Convolvulaceae
Associated Bee Species:
Apiform Crooked-legged bee
(Ancyloscelis apiformis)
Aztec sweat bee (Augochlora azteca)
Cobalt ceratina (Ceratina cobaltina)
Metallic sweat bee (Lasioglossum (Dialictus))
Marginate chimney bee (Melitoma Marginella)
Notes: At the NBC, Alamo vine is the sole or principal pollen source for species of chimney bees and crooked-legged bee that are rarely seen in most of the United States. Alamo vine blooms at the NBC throughout the fall into late November.
Nama sp
Common Names: bristly nama, wavyleaf nama
Plant Family: Boraginaceae:
Associated Bee Species:
Golden green sweat bee (Augochlora aurifera)
Honduran calliopsis (Calliopsis hondurasica)
Mission fairy bee (Perdita missionis)
Texas small carpenter bee (Ceratina texana)
Notes: Nama is an important food source throughout the Valley. It is closely associated with the Mission fairy bee and the Honduran calliopsis.
Opuntia engelmannii var. lindheimeri
Common Name: Texas prickly pear
Plant family: Cactaceae
Associated Bee Species:
Aztec sweat bee (Augochlora azteca)
Compact anthophorula (A. compactula)
Rincon himney bee (Diadasia rinconis)
Little prickly pear long-horned bee
(Melissodes opuntiellus)
Littoral cactus wood-borer bee
(Lithurgopsis littoralis)
Faintly-banded mason bee (Osmia subfaciata)
Tepanec long-horned bee (Melissodes tepaneca)
Notes: In March and early April, when Texas prickly pear blooms, it attracts a variety of generalist bees and is the sole food source for many specialist bees. The mason bee Osmia subfasciata uses plant materials from prickly pear cactus to build its nests.
Palafoxia texana
Common Name: Texas palafox
Plant family: Asteraceae
Associated Bee Species:
Affiliated masked bee (Hylaeus affinis)
Hercules sphecodes cuckoo (Sphecodes heraclei)
Panamanian masked bee (Hylaeus panamensis)
Notes: In November, small bees
like furrow bees, Hercules sphecodes and masked bees congregate in large numbers on the blossoms of Texas palafox.
Parkinsonia aculeata
Common Name: Retama
Plant family: Fabaceae
Associated Bee Species:
Parkinsonia carpenter bee
(Xylocopa tabaniformis parkinsonia)
Tepanec long-horned bee
(Melissodes tepaneca)
Notes: Retama is a principal food source of the Tepanec long-horned bee and the Parksinonsia carpenter bee during the spring. During April at the NBC, a single retama tree can be mobbed by dozens of female Tepanec long-horned bees. Parkinsonia carepnter bees, which derive their name from this plant, like to visit the topmost flowers of retama trees.
Passiflora sp.
Common Name: Passionflower
Plant family: Passifloraceae
Associated Bee Species:
Griswold's carpenter bee (Xylocopa griswoldi)
Mexican feather-tongued bee (Ptiloglossa mexicana)
Parkinsonia carpenter bee
(Xylocopa tabaniformis parkinsonia)
Notes: Several varieties of passionflower grow at the National Butterfly Center. This plant is a favorite of carpenter bees. It is among a handful of plants that attract the rarely-seen Mexican feather-tongued bee (shown here), which feeds in early morning and evening.
Phyla nodiflora
Common Name: Texas frog fruit
Plant family: Verbenaceae
Associated Bee Species:
Honduran calliopsis (Calliopsis hondurasica)
Red-faced Triepeolus (Triepeolus rufoclypeus)
Notes: This little plant is easy to overlook. It is a groundcover that grows throughout the NBC. During the fall, Texas frog fruit flowers are visited by an array of small bees and by Triepeolus cuckoo bees.
Prosopis glandulosa
Common Name: Honey mesquite
Plant Family: Fabaceae
Associated Bee Species:
Swenk's cellophane bee (Colletes swenki)
Texas agapostemon (Agapostemon texanus)
Zaptlana leafcutter (Megachile zaptlana)
Notes: This tree is an important source of pollen for several bee species, in early spring before many plants have begun blooming (February - March).
Quincula lobata
Common Name: Purple groundcherry
Plant Family: Solanaceae
Associated Bee Species:
Swenk's cellophane bee (Colletes swenki)
Texas cellophane bee (Colletes texanus)
Notes: This small plant blooms in April. It is the principal flora on which Swenk's cellophane bee appears at the NBC.
Ratibida columnifera
Common Name: Mexican hat
Plant family: Asteraceae
Associated Bee Species:
Worthy long-horned bee (Florilegus condignus)
Frisky long-horned bee (Svastra petulca)
Hercules sphecodes cuckoo bee
(Sphecodes heraclei)
Ligated furrow bee (Halictus ligatus)
Tepanec long-horned bee (Melissodes tepaneca)
Texas agapostemon (Agapostemon texanus)
Notes: Mexican hat attracts both generalist pollinators and long-horned bee species that specialize in pollinating aster family flowers.
Rhynchosia senna var. texana
Common Name: Texas snout bean
Plant Family: Fabaceae
Associated Bee Species:
Slender resin bee (Megachile exilis)
Toluca leafcutter bee (Megachile cf. toluca)
Notes: Texas snout bean is the sole documented NBC plant visited by the leafcutter species identified as Megachile cf. toluca. This bee was discovered at the NBC in fall, 2018 -- the only record of this species (and its entire subgenus) inside of the U.S. Slender resin bees also feed primarily on this plant at the NBC.
Planting more of this perennial in other areas of the NBC could add to the security of the NBC's Megachile cf. toluca and resin bee populations.
Salvia ballotiflora
Common Name: Shrubby blue salvia
Plant family: Laminaceae
Associated Bee Species:
California digger bee (Anthophora californica)
Masked sage digger bee (Anthophora capistrata)
Mournful long-horned bee (Melissodes tristis)
Slender resin bee (Megachile exilis)
Solanum exomalopsis (Exomalopsis solani)
Notes: Shrubby blue salvia is a key attractor in the Valley of the rare Texas Mesoxaea (Mesoxaea texana) and the glorious protoxaea (Protoxaea gloriosa). It is also the sole plant on which the masked sage digger bee and the mournful long-horned bee have been sighted at the NBC. The masked sage digger bee is rarely seen north of the Mexican border, but at NBC it is was a frequent visitor to this plant from late April through November.
Solanum elaeagnifolium
Common Name: Silverleaf nightshade
Plant family: Solanaceae
Associated Bee Species:
American bumble bee (Bombus pensylvanicus)
California digger bee (Anthophora californica)
Green metallic bee (Augochloropsis metallica)
Griswold's carpenter bee (Xylocopa griswoldi)
Mexican feather-tongued bee (Ptiloglossa mexicana)
Similar exomalopsis (Exomalopsis similis)
Notes: During early fall, the endangered American bumble bee is a frequent visitor of silverleaf nightshade at the NBC.
This plant requires "buzz" or vibratile pollination, and thus attracts bee species that are buzz pollinators.
Solidago sempervirens
Common Name: Seaside goldenrod
Plant family: Asteraceae
Associated Bee Species:
Golden green sweat bee (Augochlora aurifera)
Honey-footed exomalopsis (E. mellipes)
Honey-tailed agapostemon (A. melliventris)
Ligated sweat bee (Halictus ligatus)
Baker's dieunomia (Dieunomia nevadensis bakeri)
Similar exomalopsis (E. similis)
Texas cuckoo leafcutter bee (Coelioxys texana)
Notes: Seaside goldenrod is a magnet for small bee in the fall. It is the sole NBC flower on which Baker's dieunomia has appeared.
Symphyotrichum subulatum
Common Name: Hierba del marrano
Plant family: Asteraceae
Associated Bee Species:
Dwarf epeolus cuckoo bee (Epeolus pusillus)
Green metallic bee (Augochloropsis metallica)
Honey-tailed agapostemon (Agapostemon
melliventris)
Ligated furrow bee (Halictus ligatus)
Notes: Hierba del marrano is the sole plant at the NBC that has been documented as a nectar source for the beautiful, violet-eyed dwarf Epeolus cuckoo bee. Small numbers of this plant appeared at the NBC in November, 2018: all were visited by multiple specimens of this cuckoo species.
Tecoma stans
Common Name: Esperanza
Plant Family: Bignoniaceae
Associated Bee Species:
American bumblebee (Bombus pensylvanicus)
Apiform crooked-legged bee (Ancyloscelis apiformis)
Marginate chimney Bee (Melitoma marginella)
Metallic green bee (Augochloropsis metallica)
Parkinsonia carpenter bee (Xylocopa
tabaniformis parikinsoniae)
Strand's carpenter bee (Xylocopa strandi)
Notes: Esperanza provides food for both generalist and specialist bees during periods of drought and cold when few other plants are in bloom. Esperanza is a pivotal food source at NBC for carpenter bees and chimney bees; without esperanza, some carpenter bee species might well disappear from NBC. The proximity of some NBC esperanza plants to a canal may be key to the abundance of unusual chimney bees in the area. Chimney bees often require water to build their nests.
Vachellia farnesiana
Common Name: Huisache
Plant Family: Fabaceae
Associated Bee Species
Parkinsonia carpenter bee
(Xylocopa tabaniformis parkinsonia)
Notes: This native plant is a pollen source in spring for Parkinsonia carpenter bees.
Verbesina enceloides
Common Name: Cowpen daisy
Plant family: Asteraceae
Associated Bee Species:
Frisky long-horned bee (Svastra petulca)
Ligated furrow bee (Halictus ligatus)
Portly long-horned bee
(Melissoptila pinguis)
Slosson's sand-dwelling cuckoo leafcutter bee
(Coelioxys slossoni arenicola)
Zaptlana leafcutter bee (Megachile zaptlana)
Notes: Cowpen daisy is an important pollen and nectar source both for generalist bees, and for bees that specialize in aster-family plants. Cowpen daisies are visited continuously and heavily by wild bees during the fall and summer at the NBC.
Viguiera stenoloba
Common Name: Cowpen daisy
Plant family: Asteraceae
Wilmatte's long-horned bee (Eucera wilmattae)
Frisky Svastra (Svastra petulca)
Ligated furrow bee (Halictus ligatus)
Slosson's sand-dwelling cuckoo leafcutter bee
(Coelioxys slossoni arenicola)
Zaptlana leafcutter bee (Megachile zaptlana)
Notes: This plant sustains a varied array of generalist and aster-family specialist bees. It is the only NBC plant on which Sabine's long-horned bee has been found, and a principal food source for Wilmatte's long-horned bee.