Friday, May 19, 2017

Flower Friday: Pricklypear cactus is just bristling with personality.

Pricklypear flower. Photo by Stacey Matrazzo.
Pricklypear cactus (Opuntia humifusa)
Click on terms for botanical definitions.

Pricklypear cactus is an erect to sprawling perennial succulent. Its blooms are large with bright yellow petals, sepals and stamens. Petals and sepals are often indistinguishable, and may have a waxy feel. Flowers occur singularly or in clusters. Leaves are absent, replaced by flattened cladodes, commonly referred to as “pads.” The cladodes are segmented, fleshy and armed with two types of barbed bristles: long, fixed spines, and small glochids or hairlike bristles (see caution below). Flowers are born on the margins of mature cladodes. The pear-shaped fruit is hard and green; it softens and turns a bright purplish-pink as it matures. It is also covered in fine bristles.

Long, fixed barbed spines. Photo by Stacey Matrazzo.
Pricklypear cactus occurs naturally in scrub, scrubby flatwoods, sandhills, coastal strands, ruderal sites and dry, open areas. It flowers in late spring and attracts a wide range of pollinators, especially native bees. The fleshy fruits and seeds are eaten by birds, small mammals and gopher tortoises (who also enjoy browsing the pads).

Pricklypear cactus fruits and young pads are edible to humans once they have been carefully de-bristled. The ripe fruits can be eaten raw or used to make juice, jam or syrup. The pads or nopales can be sautéed or grilled.

Caution: Long spines and glochids will easily penetrate skin and can be very painful to remove. The glochids can cause skin irritation upon contact. Handle with care. For more information on handling and preparing pricklypear, visit www.wildflower.org

Mature pricklypear fruits. Photo by Mary Keim.
: Cactaceae (Cactus family)
Native range: Nearly throughout Florida
To see where natural populations of pricklypear cactus have been vouchered, visit www.florida.plantatlas.usf.edu.
Hardiness: 8-11
Soil: Dry, well-drained sandy soil
Exposure: Full sun
Growth habit: 1-3’+ tall, usually wider than tall
Propagation: Seeds, cuttings/fragments
Garden tips: Pricklypear can be easily grown and is very hardy and enduring. Plant in an obvious location where there is no risk of it being accidentally stepped on. Pad fragments will regenerate into a new plant; simply bury the end of the fragment in a sandy, sunny spot and wait for your new plant to emerge.

Pricklypear cactus plants are sometimes available from nurseries that specialize in Florida native plants. Visit www.plantrealflorida.org to find a nursery in your area.

Wednesday, May 17, 2017

Know your native pollinators: Leafcutter bees

by Jonnie Dietz, Florida Museum of Natural History

"Know your native pollinators" is a series of articles that will help you identify and appreciate Florida's varied pollinators, including bees, wasps, butterflies, moths, beetles, flies, birds and bats.

Megachilidae (commonly referred to as leafcutter, mason, orchard or cuckoo bees) are a large family of solitary nesters with distinctive and fascinating behaviors. Many are easily recognizable and can be attracted to your yard with artificial nesting boxes.

Insecta : Hymenoptera : Megachilidae

Megachile sp. carrying pollen on her abdomen.
Photo courtesy of Ian Boyd (CC BY-NC 2.0

Megachilidae is a diverse group of bees, with more than 4,000 species worldwide. This large family contains both generalists and specialists, but they’re most often seen foraging on Asteraceae (daisy or aster family), Fabaceae (pea or legume family), Lamiaceae (mint family) and Rosaceae (rose family).

Some specific examples upon which Megachilidae have been spotted foraging are:

  • Blanketflower (Gaillardia pulchella
  • Spanish needles (Bidens alba
  • Dune sunflower (Helianthus debilis
  • Thistle (Cirsium horridulum
  • Eastern milkpea (Galactia volubilis
  • Canadian germander (Teucrium canadense
  • Turkey tangle fogfruit (Phyla nodiflora
  • Beardtongues (Penstemon spp.)
  • Pricklypear cactus (Opuntia spp.)

DID YOU KNOW? Some Megachilidae species are highly specialized pollinators, with spines or hairs on their faces used to collect hard-to-reach pollen from long, tubular flowers.

Megachile sp. cutting a leaf with its mandibles.
Photo courtesy of JRxpo (CC BY-SA 2.0)
Stripes, spots and iridescent colors are just a few of the stunning features that decorate this large family of solitary nesters. Most use foreign materials to build, line, partition and seal their nest cells. Many have large mandibles (jaws) which aid in nest-building tasks, such as chewing leaves and stems, and transporting pebbles to nests.

While most bees carry pollen on their legs, the majority of Megachilidae have pollen-collecting structures on the underside of their abdomens (see photo above). If you spot a bee with bright yellow or white pollen on her belly, you can be sure it belongs to this family.

DID YOU KNOW? The name Megachilidae means “big lipped family” in Greek, in reference to their large mandibles (jaws).

Nest of a leafcutter bee
Photo courtesy of Simon Edge (CC BY-NC-ND 2.0)

Megachilidae are solitary nesters, but there is no one ideal place for these bees to make a home. Worldwide, this family demonstrates a wide variety of nesting behaviors, occupying spaces such as empty snail shells, spaces between roof shingles, insides of metal pipes, abandoned nests in the ground, and burrows in dead wood.

Resin and pine sap are collected by some species to glue together snippets of plant material. Other species are masons, building their nests with mud and pebbles in the cracks and crevices between rocks or in premade holes in wood. Still others will dig tunnels in the ground, and a few even bore their own holes into dead wood. 

Inside a mason bee (Osmia sp.) nest.
Photo courtesy of tpjunier (CC BY 2.0)
Florida Megachiliade

Florida is home to about 75 species of Megachilidae bees, so we’ll only talk in depth about the most commonly spotted genera. These include bees in genus Megachile, Osmia and Coelioxys

Genus: Megachile (Leafcutter bees)

Most Florida Megachilidae belong to this genus. They are medium-sized bees, usually black in color with white hairs, and fly from spring to late fall. Leafcutters get their name from the almost perfectly round holes that they chew in leaves and flower petals. 

Notches in bushclover leaves cut by Megachile sp.
Photo courtesy of Jonnie Diet
At first glance, gardeners may fear there’s a hungry pest in their midst, but these plant pieces are not used for food. Instead, the collected material is essentially used as a wallpaper to protect the Megachile nest cells from moisture. Once inside her nest, the bee chews the leaf’s edges until it becomes sticky enough to adhere to the cell walls. Each cell is provisioned with a mixture of pollen and nectar and partitioned with additional plant material. If you were to remove a completed nest from its cavity, it would resemble a small, leafy cigar. 

Leafcutters tend to nest in premade cavities in wood, such as beetle burrows, hollow stems and artificial nesting boxes. Some, however, nest in the ground or use alternative materials such as mud, sap or pebbles to line their cells.

Note: Holes cut by leafcutters rarely compromise the health of a plant, so gardeners can take pride in knowing they have pollinators nesting nearby!

DID YOU KNOW? The distinctive notches that Megachile bees chew into leaf edges have been found in plant fossils dating over 30 million years, indicating leafcutters have been around for a very long time.

Genus: Osmia (Mason or Orchard bees)
Osmia chalybea. Photo courtesy of USGS
Native Bee Inventory and Monitoring Laboratory
Often referred to as mason bees, most bees in this genus are a bright iridescent blue, green or black. Once again, their name is a descriptor of their nest-building behavior. Most use mud to line their nest cells, but others will use chewed plant materials. 

These bees prefer to find premade holes in which to build their nests, including hollow stems, pine cones, cracks in rock or artificial nesting boxes. Others will use pebbles and mud to construct a nest on the surface of rock or other hard surface. In general, nest cells are partitioned with mud or plant material and each cell is each provisioned with a ball of pollen and nectar.

Keep a vigilant eye out for these beautiful bees, as they typically have a short flying season that only lasts from spring through early May.

DID YOU KNOW? Osmia spp. are responsible for pollinating many orchard crops, such as almonds, apples, cherries and plums. In fact, they’re more efficient at pollinating these crops than honey bees, making them some of the most economically important bees in North America.

Genus: Coelioxys (Cuckoo bees)
Note the tapered abdomen of Coelioxys sayi, a kleptoparasitic bee.
Photo courtesy of the USGS Native Bee Inventory
and Monitoring Laboratory
These bees are kleptoparasites. Instead of building their own nests, they will locate and parasitize the nests of other bees in the Megachile genus. Because they don’t provision for their own young, adult cuckoo bees have no pollen-carrying structures on their bodies and are significantly less hairy. Their extremely tapered abdomens are designed to pierce through the leafy nest cells of Megachile bees, where the Cuckoo bee will then lay an egg. Once the Coelioxys larvae hatches, it kills the resident leafcutter larvae and consumes its food provisions. These bees may not have to make and provision their own nests, but they are completely dependent upon other species for their survival.

Other Florida genera 

Other Florida Megachilidae genera include Lithurgus, Anthidium, Stelis, Trachusa, Paranthidium, Anthidiellum, Dianthidium, Heriades, Ashmeadiella and Hoplitis.

In general, bees in these groups are less common and less widely distributed than those in the three genera featured above, but they are no less intriguing. We just couldn’t leave them out entirely, so here’s a quick fact about each one:

  • Lithurgus: There is only one known species in Florida: Lithurgus gibbosus. They specialize on prickly pear cactus (Opuntia spp.) and are found nesting in dry wood.
  • Anthidium: There is only one known species in Florida: Anthidium maculifrons. This soil-nesting species collects plant hairs and pebbles for nest construction.
  • Stelis: These bees parasitize other Megachilidae bees.
  • Trachusa: These are ground-nesting bees that dig their own burrows.
  • Paranthidium: These ground-nesters dig their own burrows in sandy soil and collect resin and gum to partition the nest cells.
  • Anthidiellum: This genus prefers open nests that they construct with resin.
  • Dianthidium: These bees build exposed nests by gluing pebbles together with resin.
  • Heriades: Bees of this genus are small, ranging from 4 mm to 7 mm in size.
  • Ashmeadiella: Ranging from 3.5 mm to 9.5 mm in size, this genus usually nests in stems or preexisting holes in wood.
  • Hoplitis: These bees build their nests in pithy stems.
  1. "The Bees of Florida." John B. Pascarella, Ph.D., Dean of the College of Sciences, Professor of Biological Sciences, Sam Houston State University, Huntsville, Texas. http://entnemdept.ufl.edu/HallG/Melitto/Intro.htm  
  2. Michener, Charles D. The Bees of the World. Baltimore: Johns Hopkins U Press, 2010. Print.
  3. “Florida's Native Bees." Jaime Pawelek. http://www.floridasnativebees.com/plasterer-bees.html
  4. Mitchell, Theodore B. Bees of the Eastern United States, Volume 2. Raleigh, NC: Published by the North Carolina Agricultural Experiment Station with Support from the National Science Foundation, 1962. Print.
  5. Wilson, Joseph S., and Olivia Messinger Carril. The bees in your backyard: a guide to North America's bees. Princeton: Princeton U Press, 2016. Print.
  6. The Xerces Society. Attracting Native Pollinators: The Xerces Society Guide to Conserving North American Bees and Butterflies and Their Habitat. North Adams, MA: Storey Pub., 2011. Print.

Friday, May 12, 2017

Flower Friday: Pinewoods milkweed

Photo by Eleanor Dietrich
Pinewoods milkweed (Asclepias humistrata)

Click on terms for botanical definitions.

Also known as sandhill or purple milkweed, pinewoods milkweed is a robust perennial wildflower, with large, thick leaves and a somewhat sprawling growth habit.

Its distinct flowers are pinkish-white to pale purple and are born in terminal umbels. Individual flowers have reflexed corollas and an upright corona — a characteristic typical of milkweed flowers. Leaves are dull grayish-green with conspicuous pink to lavender veins; the leaf color darkens to almost purple as the plant matures. Leaves are clasping, elliptic to ovate, and can grow up to 6" long and 3-4" wide. Leaf arrangement is opposite. The plant’s many stems may be prostrate or ascending and grow in various directions. Like other milkweeds, it contains a toxic milky sap. Seeds are born in erect follicles that dry and split open as the fruit matures. Each seed is attached to a white silky pappus that catches the wind and aids in dispersal.

Pinewoods milkweed occurs naturally in sandhills, scrub and dry, ruderal areas. It blooms in spring and summer, attracting many pollinators including wasps and butterflies. Pinewoods milkweed is a larval host plant of monarch and queen butterflies.

The genus Asclepias is named for Asclepius, the Greek god of healing. The species epithet, humistrata, comes from the Latin humis, or “sprawling,” and sternere, which means “to spread,” referring to its low sprawling growth habit.

Photo by Eleanor Dietrich
: Apocynaceae (Dogbane family)
Native range: Panhandle, north and central peninsula
To see where natural populations of pinewoods milkweed have been vouchered, visit florida.plantatlas.usf.edu.
Hardiness: Zones 8a-9b
Soil: Deep, well-drained sandy soil
Exposure: Full sun
Growth habit: 1-3' tall, 1' wide
Propagation: Seed
Garden tips: Pinewoods milkweed may be difficult to transplant due to its long taproot and is best propagated from seed. If planted in excessively moist, poorly drained or rich, organic soils, the plant will quickly rot and perish.

Pinewoods milkweed plants are occasionally available from nurseries that specialize in Florida native plants. Visit www.plantrealflorida.org to check availability at a nursery in your area.

Friday, May 5, 2017

Flower Friday: Shiny blueberry

Photo by Mary Keim
Shiny blueberry (Vaccinium myrsinites)
Click on terms for botanical definitions.

Shiny blueberry is a low evergreen shrub that flowers heavily in the spring. It occurs naturally in mesic pine flatwoods, sandhills, scrubby flatwoods, dry prairies and scrub habitats. The flowers attract a variety of pollinators. The fruits are consumed by birds and other wildlife – humans enjoy them, too!

Blooms are white to whitish-pink, urn-shaped and born in clusters. Sepals vary from green to dark pink. The alternately arranged leaves are elliptic to ovate with entire margins. They are glossy green on top, while the undersides have red glands that require magnification to see. Fruits are globose berries that turn purplish-black and glaucous when ripe. Fruiting typically occurs in late spring and early summer.

Photo by Mary Keim
Family: Ericaceae (Heath or heather family)
Native range: Nearly throughout
To see where natural populations of Shiny blueberry have been vouchered, visit florida.plantatlas.usf.edu.
Hardiness: Zones 8-10
Soil: Moist to very dry well-drained acidic soils
Exposure: Full sun to partial shade
Growth habit: 1-2’ tall and wide
Propagation: Division, ground layering, seed (can be difficult to germinate)
Garden tips: Shiny blueberry is densely vegetated and is suitable for a low hedge or border plant. It works well in a naturalistic landscape as well as a container. According to A Gardener’s Guide to Florida’s Native Plants, solitary plants rarely form fruit; two plants that are genetically unrelated are needed in order for maximum fruit production.

Shiny blueberry plants are occasionally available from nurseries that specialize in Florida native plants. Visit www.plantrealflorida.org to find a nursery in your area.

Friday, April 28, 2017

Flower Friday: Gulf purple pitcherplant

Photo by Eleanor Dietrich
Gulf purple pitcherplant (Sarracenia rosea)
Click on terms for botanical definitions.

Gulf purple pitcherplant is a insectivorous perennial wildflower that blooms in spring. It occurs naturally in wet prairies, seepage slopes and roadside ditches.

The flowers of the Gulf purple pitcherplant are light to dark pink, with five petals and five sepals. They are solitary and nodding. The leaves tend to lie flat on the ground. They are tubular or urn-shaped with exposed, upward-facing mouths that form the “pitcher” where insects become trapped. The upper portion is often inflated. The fruit is a capsule with many seeds.

Gulf purple pitcherplant is a state-listed threatened species. It was originally classified as a variety of purple pitcherplant (Sarracenia purpurea) by American botanist Edgar Wherry, who referred to it as a "mutant" form. In 1999, the case for reclassification was made because of three distinguishing factors noted in populations occurring along the Gulf Coast: Flowers are larger and flower stalks are shorter; petals are pink, not purple, and pitcher structure is different. 

Open mouth of "pitcher"
Photo by Eleanor Dietrich

The species name rosea refers to the pink or rose-like color of the flower (as opposed to purpurea, which means “purple”).

Family: Sarraceniaceae (Pitcherplant family)
Native range: Gadsden and Liberty counties west into Escambia County.
To see where natural populations of Gulf purple pitcherplant have been vouchered, visit florida.plantatlas.usf.edu.
Hardiness: Zones 7-8a
Soil: Inundated to saturated soils; can also grow in periodically flooded habitats
Exposure: Full sun
Growth habit: <1’ tall
Propagation: Division, seed
Garden tips: Gulf purple pitcherplants do best in their natural habitat. They should not be harvested or collected without permission because of their threatened status.