South Florida Field Trip - Part 1

On Saturday, August 24, 2013, Michael Manna and I took a short, one-day botanical field trip to Miami-Dade County. While Michael had breakfast with his wife and daughter, I took the opportunity to look at some of his plants. So, in a sense, the botanical field trip began at his home. Michael is one of the few gardeners in Palm Beach County who has an extensive collection of carnivorous plants and I immediately headed straight for the carnivores.

As I entered the backyard, I was greeted by several Nepenthes (tropical pitcher plants), among which was Nepenthes 'Red Dragon', a plant with sizeable green pitchers accented with an attractive red peristome (pitcher rim) and operculum (pitcher lid).

Nepenthes 'Red Dragon'

On the way to his American pitcher plant collection (Sarracenia species), I passed several tubs of aquatic plants, most of which had a native duckweed, Spirodela polyrhiza, growing in them. This plant is known as "common duckweed" but I find that, at least in Palm Beach County, it is less common than the dotted duckweed, Landoltia punctata, a non-native plant whose invasive tendencies are often overlooked because most people assume all duckweeds are native. One tub appeared to be filled with a delicate coon's tail (Ceratophyllum species) but upon closer inspection, the plants turned out to be the waterwheel plant (Aldrovanda vesiculosa). The latter is a remarkable aquatic carnivorous plant related to the Venus flytrap (Dionaea muscipula). Like the Venus flytrap, Aldrovanda vesiculosa also possesses snap traps, although in Aldrovanda the traps are adapted for catching small aquatic prey. The traps are tiny but they can capture prey much larger than themselves as can be seen in the YouTube Video embedded below.

Spirodela polyrhiza, common duckweed.

Aldrovanda vesiculosa, the waterwheel plant, growing with Spirodela polyrhiza, common duckweed. Note the whorled leaves, each of which bears a tiny snap trap. The traps are similar to those of the Venus flytrap but are much smaller.

The Sarracenia collection had dwindled somewhat from its former glory because Palm Beach County winters are a tad too warm for most sarracenias to have a proper winter dormancy; however, the ones that had persisted were doing well. I was glad to see S. leucophylla, perhaps among the most vegetatively beautiful plants native to Florida. And S. ×catesbaei had also persisted, having formed a relatively large specimen.

Sarracenia leucophylla, the whitetop pitcher plant.

Sarracenia ×catesbaei, the hybrid of S. flava and S. purpurea.

After admiring the carnivorous plants, I made my way back to the front yard, stopping to admire what is probably the largest firebush (Hamelia patens) in the county. It was about as tall as Michael's house, nearly twice as wide, and covered with innumerable quantities of bright orange-red tubular flowers. It presented a spectacular sight in the early morning light but, because I had only my macro lens with me, I was unable to photograph it. Also catching my attention was a beautiful Ixora hybrid with large dark green leaves and contrasting white flowers with flower buds blushed an attractive shade of pastel pink.

Ixora hybrid with white flowers and pink-blushed flower buds.

For more of Michael Manna's carnivorous plants, see my previous post of a visit to Michael's former home and garden.

Go to Part 2 of a "South Florida Field Trip."
Go to Part 3 of a "South Florida Field Trip."
Go to Part 4 of a "South Florida Field Trip."

Images and text © 2013 Rufino Osorio

Yellow Flatsedge – Cyperus croceus

A large, robust plant of Cyperus croceus growing in a patch of pineland heliotrope (Heliotropium polyphyllum) in my front yard.

Cyperus croceus is a common native perennial that has been recorded from all but 12 counties in Florida. Since it occurs in a wide variety of habitats, including marshes, hammocks, sand scrub, sandhills, flatwoods, and disturbed areas, it likely occurs in every county in Florida. In urban areas, it can be found as a weed of neglected lawns, in fields, and along roadsides. It is also one of a group of natives that occurs spontaneously in my yard, especially in sunny areas where there is exposed soil devoid of mulch. Its common name is usually listed as "Baldwin's flatsedge," which is derived from a synonym for this species: Cyperus baldwinii. I prefer the more descriptive common name of "yellow flatsedge," derived from the species epithet, croceus, which means "saffron yellow." But bear in mind that the spikes are greenish when young, brownish when mature, and only somewhat yellowish for a brief period in between.

Younger, smaller plants have a graceful, rather delicate appearance.

As one can well imagine, a plant that readily grows in both the wet soils of marshes and the dry sand of sandhills, in full sun to light shade, is effortlessly cultivated and it can often be established by simply scattering seeds in an open, sunny area. It is, as far as I know, never intentionally cultivated but I could see it being used as a 1–2 foot (0.3–0.6 meters) tall groundcover in a dry, sandy site where little else will grow well. It adapts very well to being mowed and I have seen lawns consisting mostly of Cyperus croceus in older urban neighborhoods. Wildlife value appears to be limited but it may serve as a larval food plant for Diploschizia impigritella, the yellow nutsedge moth. In wetland areas, its tiny, seedlike fruits are eaten by waterfowl and the foliage may be eaten by geese.

A close-up view of an early-stage inflorescence.

Although it can be a bit weedy, yellow flatsedge grows in clumps and lacks underground rhizomes. Thus, it is easily weeded out by slicing the bottom of the plant from its roots. So long as no vegetative portion remains attached to the roots, it will not grow back. A few plants, here and there, add variety, texture, and interest to native plant gardens and, so long as bare soil is covered with mulch, leaf litter, or other plants, it rarely presents a serious weed problem. However, plants can form sizeable clumps, as seen in the first image above, and so it should be kept a safe distance from small or delicate wildflowers.

Images and text © 2013 Rufino Osorio

Pine Honey is an Actual Thing

I had always assumed that honey was made only from the nectar of flowers; however, I recently learned about pine honey while surfing the internet. Pine trees do not produce flowers in the botanical sense of the word, rather, they produce cones and cones do not produce nectar. So how could pine honey be an actual thing?

It turns out that in the eastern Mediterranean, mainly in Greece and Turkey, there occurs a scale insect of pine trees with the scientific name of Marchalina hellenica. The insect sucks pine tree sap and, because the sap contains more sugars than the insect can use, it excretes the excess sugars as honeydew. Forest honey bees collect the honeydew and convert it into pine honey.

Although the fact that it existed was a surprise, I was not at all surprised to learn that pine honey is not particularly sweet and has a distinctive, slightly bitter flavor with a strong aroma (Benefits of Honey 2013).

Pine honey is not simply an unusual novelty item. It is an economically important product accounting for almost 65% of annual honey production in Greece and about 50% in Turkey (Hatjina & Bouga 2009). As is done with other monofloral honeys, beekeepers will transport their hives to pine forests during peak honeydew production.

References:

Benefits of Honey. 2013. Exploring Honey Varieties. Internet: http://www.benefits-of-honey.com/honey-varieties.html. Visited 25 August 2013. Link

Hatjina, F. and M. Bouga. 2009. Portrait of Marchalina hellenica Gennadius (Hemiptera: Margarodidae), the main producing insect of pine honeydew—biology, genetic variability and honey production. U. Arı Drg. 9(4): 162–167. PDF

© 2013 Rufino Osorio

Euphorbia thymifolia – Thyme-leaf Sandmat

Euphorbia thymifolia (synonym: Chamaesyce thymifolia) is an unassuming little annual native from Mexico to Argentina, the West Indies, and the paleotropics (Africa and Asia). It has been introduced in the Hawaiian islands and is considered by some to have been introduced in Florida, but the Atlas of Florida Vascular Plants lists it as native. I have observed it at three sites in Florida: (1) in pavement cracks in downtown Tampa; (2) near the mouth of a gopher tortoise burrow in a sandhill habitat in Tampa; and (3) in a highly disturbed old field that had originally been sand scrub at Jonathan Dickinson State Park in Martin County.

A young plant growing under very harsh conditions in a tiny crack in the street in front of my house.

As is the case with most annual, weedy spurges formerly in the genus Chamaesyce, it is very easily grown and, once introduced into a garden, you will likely have it forever. Although it can be a weed of potted plants, thus far it has not been a problem in the garden. Certainly, it is nowhere near as aggressive and abundant as the quadrumvirate of weedy spurges in my yard that can sometimes number in the hundreds: Euphorbia graminea, Euphorbia hirta, Euphorbia hypericifolia, and Euphorbia ophthalmica.

Images and text © 2013 Rufino Osorio

Parthenocissus quinquefolia – Virginia Creeper

A Virginia creeper, Parthenocissus quinquefolia, has ripened its fruit in early spring. The combination of red stalks and dark purple fruit is an indication that the fruits are adapted for dispersal by birds. I can assume bird dispersal because birds can see red but most mammals cannot. Thus, bird-dispersed fruits tend to have red colors somewhere in the infructescence. Often, the fruits themselves are red but in other cases the leaves, bracts, stalks, and/or calyx may be red. In some bird-dispersed plants, the seeds themselves may be red and in a few instances, such as Jamaican caper (Capparis cynophallophora), the fruits split open to reveal a red inner lining.

Virginia creeper is a very hardy plant that is tolerant of a wide variety of conditions. This particular plant was found growing in an alley on a south-facing garage wall near West Palm Beach's city center.

Image and text © 2013 Rufino Osorio

Mounts Botanical Garden

A miscellany of photographs taken at Mounts Botanical Garden this year.

Adenium obesum setting seed pods.

Aechmea 'Big Harv'

Aloe dorotheae, an aloe that can assume bright red, burgundy, and mahogany-red colors when stressed by cold weather or intense sunlight.

Alternanthera dentata 'Purple Knight'

Medinilla cummingii 'Kinabalu' with Alternanthera dentata 'Purple Knight'

Medinilla cummingii 'Kinabalu' is probably the easiest Medinilla to grow in south Florida.

Euphorbia punicea

Euphorbia punicea (I'm not sure what those white spots are about.)

Salvia elegans, commonly known as pineapple sage, and with fruit-scented leaves.

Images and text © 2013 Rufino Osorio

Brazilian-Pepper in 3-D

Earlier this year, I photographed the fruits of the notoriously invasive Brazilian-pepper (Schinus terebinthifolius). While studying the images later that day, I realized that I could combine two of the images to make a 3-D gif. Such gifs are interesting because they achieve a 3-D effect by wiggling two images back and forth. The appeal of such gifs is that no glasses, special equipment, or effort is needed to see the 3-D effect.

Above is a regular image of the Brazilian-pepper. Below, is the same image which I have combined with a second image to produce a 3-D gif.

Images and text © 2013 Rufino Osorio

Johnny Poke Seed

Early last year, I collected a few seeds from a pokeweed, Phytolacca americana, that had spontaneously arisen among some saw palmetto palms (Serenoa repens) in a local park. The seeds were duly planted and I selected one seedling to pot up and, eventually, plant in the ground in my front yard. That plant happily grew and produced an enormous number of fruits, much to the delight of the local mockingbirds. Unfortunately, its large size was threatening its more delicate neighbors so I consigned it to the compost bin.

This spring, I noticed its progeny popping up here and there. The photograph above shows a plant growing in my neighbor's yard along our mutual fence line. The picture below is a close-up of the flowers of that same plant. Another plant showed up on my property about 100 feet (30.48 meters) from where the parent plant had been removed. And speaking of the parent plant, a seedling came up inches away from the site of the original plant and that seedling is now about 3 feet (0.9 meters) tall and beginning to flower and fruit. It looks as if pokeweed is here to stay in my yard and, with the help of some feathered friends, perhaps other yards and vacant lots in the neighborhood.

Update: Since this blog post was published on 22 June 2013, the pokeweed established about 100 feet (30.48 meters) from the parent plant died. When I pulled it up from the ground, its root system had rotted, presumably as the result of the torrential, record-breaking rains that Palm Beach County had this spring and early summer.

Images and text © 2013 Rufino Osorio

The Problems with Pilea glauca and Pilea glaucophylla

A small, trailing, groundcovering plant known as Pilea glauca is readily available on the internet. See, for example, the online store of Josh's Frogs or Pernell Gerver's online store. Other web sites list the plant as Pilea glaucophylla. The plant is both common enough and popular enough to have two common names: silver sprinkles and gray artillery plant.

There is, however, one big problem with the name, Pilea glauca. It has never been published. Although the name is in use by the gardening public, the name does not appear in any database of botanical names, including The International Plant Names Index or Tropicos. It is an example of what is known in botany as a nomen nudum, which literally translated means a naked name. In standard botanical practice, each name is tied to a type, that is, an herbarium specimen on which the name is based and each name must be legitimately published if the name is to be considered valid. However, Pilea glauca is floating around the internet completely naked, bereft of the "clothing" provided by a type specimen and legitimate publication.

The name Pilea glaucophylla has neither problem. It was legitimately published in 1936 by E.P. Killip in a publication titled Contributions to the United States National Herbarium and there is a type specimen collected by É.F. André in Colombia and deposited in the herbarium of the Smithsonian's National Museum of Natural History. Unfortunately, there's one small problem: we can search for it at the Smithsonian's NMNH herbarium website and we can see for ourselves that Pilea glaucophylla is a completely different plant than the one circulating on the internet by the name of Pilea glaucophylla.

So, what is the name of this mystery plant? I know that it is definitely not Pilea glauca since that is a nomen nudum that has never been published. And I know that it is not Pilea glaucophylla since that name refers to a completely different plant with erect stems and differently shaped leaves that are about 3-inches (7.6 centimeters) long or longer. I thought that I would never learn its name; however, thanks to the original version of this blog post and the power of the Internet, I heard from David Scherberich of the Jardin Botanique de la Ville de Lyon in France, who informed me that he knows the plant as Pilea libanensis of Cuba. Neither David nor I have confirmed that it is indeed that species by examining vouchered herbarium specimens but a preliminary search on the Internet confirms that Pilea libanensis is very likely the name of our little, silvery, carpeting Pilea.

It is easy to understand how this example of folk taxonomy came about. Pilea libanensis has silvery-green or silvery-bluish leaves that resemble in color the glaucous foliage of some landscape shrubs and trees, especially that of certain conifers. Therefore, at least until now, no one questioned the validity of either Pilea glauca, which means "glaucous Pilea," or Pilea glaucophylla, which means "glaucous-leaved Pilea," because both names aptly fitted the plant. But these incorrect names should not be used and, for now, I am referring to it as Pilea libanensis.

Note: This post was modified from its original version, published on 22 June 2013, by including information in a personal communication by email from David Scherberich dated 12 August 2013.

Image and text © 2013 Rufino Osorio

Sideroxylon tenax – Tough Bumelia

Tough bumelia is a common, thorny, deciduous or evergreen shrub or small tree native to North Carolina, South Carolina, Georgia, and Florida. It occurs nearly throughout Florida but is wholly absent from the Panhandle and the western portion of northern Florida. It is found in nature in dry, well-drained soils in full sun to light shade in sandhills, sand scrub, and coastal hammocks. The lower surface of the leaves are completely covered with a dense layer of silky hairs that varies from pale brown to a rich mahogany brown. This dense coat of hairs no doubt slows down the loss of water through transpiration and is an adaptation to the plant's xeric habitat.

Tough bumelia, like other Sideroxylon species, is a wildlife powerhouse since the dense, thorny branches provide protection for small birds and animals, the tiny white flowers attract an extremely wide variety of insect pollinators, and the dark, 1-seeded, olive-sized fruits have a gummy, but sweetish, pulp that is eaten by larger birds and various mammals.

In older works, tough bumelia is often listed as Bumelia tenax. Also, it is often described as being "spiny" but that is incorrect. Spines, in the strict sense, refer to modified leaves or their parts. Bumelia tenax is more correctly referred to as "thorny" since its sharp-pointed armature is derived from modified branches, not modified leaves.

Image and text © 2013 Rufino Osorio