Saturday, September 28, 2013

Pentas lanceolata 'Gloria's Heirloom Pink'

Pentas lanceolata - Egyptian star flower - Pentas
Pentas lanceolata 'Gloria's Heirloom Pink'

Pentas lanceolata is an evergreen perennial or subshrub native to Africa and Yemen that is commonly used as a flowering landscape plant in frost-free areas and as an annual or houseplant in colder regions. Old-fashioned cultivars are rather large plants that grow to about 4 feet tall and wide, whereas modern cultivars tend to be more compact. Its common names are listed in a variety of references as Egyptian star flower or Egyptian star cluster, but, at least in south Florida, it is never known by those names and it is always referred to by the common name of pentas.

Pentas is very easily cultivated in well-drained but moist soil in full sun to light shade and it is easily propagated from seeds or cuttings, with the cuttings rooting easily in either a glass of water or soil. Poorly drained soils promptly lead to root rot and it struggles in excessively dry soil, thus, it is best to keep it moderately moist and to avoid extreme garden situations. It is much cultivated for the attractive flowers, which are borne throughout the year and come in shades of white, pink, red, magenta, and lavender. The flowers will last about five days when cut and placed in a vase of water and pentas is sparingly used as a cut flower and in flower arrangements.

Pentas is also highly recommended for butterfly gardens as a nectar plant. Unfortunately, modern cultivars are not particularly attractive to butterflies and, if used in butterfly gardens, one needs to seek out the large, old cultivars. One of these is 'Gloria's Heirloom Pink'. It is a selection found by the outstanding native plant gardener, Gloria Hunter, in the 1950s on the island of Palm Beach. It is a vigorous plant with bright pink flowers and in my garden it is a great favorite of honeybees and gulf fritillary, monarch, and queen butterflies. This cultivar is sparingly found in cultivation in the West Palm Beach region, mostly in the gardens of native plant enthusiasts with whom Gloria has generously shared cuttings.

Pentas lanceolata with a gulf fritillary butterfly (Agraulis vanillae)
Pentas lanceolata 'Gloria's Heirloom Pink' with a gulf fritillary butterfly (Agraulis vanillae).

Although pentas has been cultivated in the untold thousands throughout southern Florida, it has not shown invasive tendencies and it has been found outside of cultivation in Florida only in Miami-Dade County. I have seen such wild plants growing in moist, partially shaded, rocky places in Miami-Dade County but they had reverted to their wild form and were scarcely recognizable as pentas. The plants were rather spindly, wispy things barely a foot tall and with dull whitish flowers. I found this unusual since cultivated plants that revert to their wild form are usually more vigorous than the cultivated forms but these were decidedly less vigorous. Also, and perhaps the reason pentas has not shown invasive tendencies, they appeared short-lived, were never found in large numbers, and occurred in sites only where there was little or no competition from other plants.

Images and text © 2013 Rufino Osorio

Sunday, September 15, 2013

South Florida Field Trip - Part 4

The last stop of our short field trip was the Navy Wells Pineland Preserve near Homestead, Florida, a little ways south of the Robert is Here Fruit Stand and Farm and north of Everglades National Park. Unlike Palm Beach County, which has some kind of public access to most of its county-designated natural areas, most natural areas in Miami-Dade County have no public access and no trespassing signs were posted throughout the perimeter of the preserve. Michael Manna and I, however, had received permission from one of Miami-Dade County's land managers and were able to visit the preserve.

no trespassing sign at Navy Wells Pineland Preserve
The above sign was posted throughout the perimeter of the Navy Wells Pineland Preserve.

Navy Wells Pineland Preserve has an extremely rich rock pineland flora consisting of numerous grasses, herbaceous wildflowers, vines, and shrubs, many of which are near the northern limits of their natural range and are designated as state-listed threatened or endangered plants. A complete list of the nearly 400 plant species that have been recorded at Navy Wells is available from the Institute for Regional Conservation's web site. Below are a few images that only hint at the rich variety of plants we saw.

Rhynchosia reniformis
Rhynchosia reniformis differs from all other Florida members of its genus in its erect or suberect growth habit; leaves consisting of a single leaflet (instead of three leaflets); and pods conspicuously longer than the calyx.

Callicarpa americana - American Beautyberry
American beautyberry (Callicarpa americana).

Trema micrantha
Trema micrantha bore flowers, unripe fruits, and ripe fruits simultaneously.

Euphorbia pinetorum - Poinsettia pinetorum
Euphorbia pinetorum (synonym: Poinsettia pinetorum) has dark green leaves that are often suffused with burgundy. It is a state-listed endangered plant. 

Hieracium megacephalon
Hieracium megacephalon has small yellow flowerheads less than an inch across but they are very showy when closely examined.

Hypoxis sessilis
Hypoxis sessilis was easily overlooked unless it was in flower.

Koanophyllon villosum
Koanophyllon villosum was one of many examples of unusual and rare shrubs growing at Navy Wells Pineland Preserve with tropical affinities and that reach their northern range limits in Miami-Dade County. It is related to the genus Eupatorium and looks very much like a shrubby Eupatorium. The white autumn flowers are very attractive to butterflies and the leaves of some plants, including those at Navy Wells, have a subtle but distinct minty fragrance when crushed.

Indigofera spicata
This image of the non-native Indigofera spicata gives a good indication of the substrate that most plants are growing in at the Navy Wells Pineland Preserve. Note how small the plant is at the end of August in spite of there having been abundant rain during the spring and summer. As a lawn or roadside weed in Palm Beach County, this same plant would have had meter-long stems and abundant flowers and fruits.

Go to Part 1 of a "South Florida Field Trip."
Go to Part 2 of a "South Florida Field Trip."
Go to Part 3 of a "South Florida Field Trip."

Image and text © 2012 Rufino Osorio

South Florida Field Trip - Part 3

This is the third part of a four-part series of blog posts on a short botanical field trip to south Florida.

Our second stop of the field trip was right-of-way road along a canal that had been cut through lime rock. This did not seem like a particular interesting site but it turned out to have a wide variety of grasses, sedges, small herbaceous wildflowers, assorted vines, and various woody plants. And, in a dark, shady spot where a few trees had formed a small grove, Michael Manna found Adiantum tenerum, a native maidenhair fern.

right-of-way road of a canal that cuts through Florida's everglades
The right-of-way road of a canal was our second stop.

A variety of Euphorbia species were easily seen at this site, including the common and weedy wild poinsettia, Euphorbia cyathophora. Wild poinsettia is very easily grown in any moist to dry lightly shaded to sunny spot but it is remarkably weedy in garden settings and I have had occasions where literally several hundred plants were growing in my garden at one time. They are pretty enough when in full flower but they are annuals and are decidedly less attractive as they slowly decline as they go to seed.

Euphorbia cyathophora - Poinsettia cyathophora - Wild Poinsettia
The narrow leaf form of wild poinsettia, Euphorbia cyathophora (synonym: Poinsettia cyathophora).

Euphorbia cyathophora - Poinsettia cyathophora - Wild Poinsettia
The true flowers of Euphorbia cyathophora are inconspicuous but they are subtended by modified leaves (bracts) that are brightly colored in various shades of red or orange-red just like the larger, showier Christmas poinsettia.

Euphorbia cyathophora - Poinsettia cyathophora - Wild Poinsettia
The broad leaf form of Euphorbia cyathophora is so distinct as to appear to be a different species but every gradation between narrow leaf and broad leaf forms can be found in nature.

I am inordinately fond of sandmat Euphorbia species, which were formerly referred to the segregate genus, Chamaesyce. So I could barely contain my excitement to see that the state-listed endangered plant, Euphorbia conferta was common at this site. It was joined by Euphorbia mendezii, a plant that, at least in south Florida, commonly occurs in disturbed rocky areas. And a third sandmat Euphorbia species (pictured below) was new to me. It was unusual in forming a rounded mat of prostrate stems with a perimeter of ascending flowering stems.

Euphorbia conferta - Chamaesyce conferta
Euphorbia conferta (synonym: Chamaesyce conferta), the plant in the center of the image, is a state-listed endangered species. Here it grew with an assortment of weedy plants and grasses. The tiny yellow daisy in the lower right is Pectis glaucescens.

Euphorbia conferta - Chamaesyce conferta
Euphorbia conferta covered by shallow water that has accumulated in a shallow depression in the lime rock after a rain storm.

Euphorbia species - Chamaesyce species
An unidentified Euphorbia species.

Completely new to both me and Michael Manna was Tournefortia volubilis, an unusual woody vine in the borage family with tiny yellow-green flowers. It would be interesting to see what pollinates such unusual little flowers. The fruits are pea-sized white berries with two, or sometimes three, conspicuous purplish-black or black spots.

Tournefortia volubilis
Tournefortia volubilis

In one area, there was a thick growth of Ipomoea hederifolia, an annual or short-lived vine sometimes grown in butterfly or hummingbird gardens for its showy, eye-catching orange or orange-red flowers. But it should not be introduced into small, tidy gardens since it produces numerous, rather unattractive seed capsules and, if conditions are to its liking, it can produce hundreds of self-sown seedlings and can overrun the garden.

Ipomoea hederifolia
Ipomoea hederifolia

We also saw Cissus verticillata, in the grape family (Vitaceae), growing in thickets. It is fairly uncommon in Palm Beach County but was rather common throughout our field trip and, later in the day, we saw it along roadsides as well as climbing fences around avocado groves.

Cissus verticillata
Cissus verticillata

Although the vines were interesting and not something we see every day in Palm Beach County, it was the abundant and varied grasses, sedges, and small wildflowers that most held my attention and the next three images are but a sample of the variety of small herbaceous plants that we found along the canal right-of-way road.

Stachytarpheta jamaicensis
Stachytarpheta jamaicensis, the native blue porterweed, was rather inconspicuous but common throughout the site.

unidentified Malvaceae species
An unidentified member of the hibiscus family (Malvaceae) growing with a few of the many species of grasses found along the canal right-of-way.

Sida ciliaris
Although it has unusual salmon orange or salmon pink flowers, Sida ciliaris was easily overlooked since it rarely exceeded an inch in height. It was but one example of the remarkable assemblage of small, herbaceous plants found at the site.

Go to Part 1 of a "South Florida Field Trip."
Go to Part 2 of a "South Florida Field Trip."
Go to Part 4 of a "South Florida Field Trip."

Image and text © 2012 Rufino Osorio

South Florida Field Trip - Part 2

This is the second part of a four-part series of blog posts on a short botanical field trip to south Florida.

Our first stop of the field trip was a roadside ditch along U.S. Route 27 in southern Broward County, where it runs beside the eastern edge of the Florida everglades.

Florida's everglades as seen from U.S. Route 27
The Everglades, as seen along U.S. Route 27 in Broward County just north of Miami-Dade County. In the background, one can see killed melaleuca trees (Melaleuca quinquenervia). Without control efforts, much of the Everglades would be a monoculture of melaleuca.

Growing in very large patches in the road median and along the sides of the road was Ruellia ciliatiflora, originally native to South America but now becoming common in south Florida. It is distinct from native Ruellia species in its flowers, which are borne in a stalked inflorescence above the uppermost leaves. In contrast, native south Florida Ruellia species bear their sessile (stalkless) or very short-stalked flowers in the axils of the leaves.

Ruellia ciliatiflora
Ruellia ciliatiflora, a native of South America, is spreading in south Florida.

Joining Ruellia ciliatiflora along the roadsides of U.S. Route 27 was Euphorbia heterophylla, a weedy Florida native plant. The Atlas of Florida Vascular Plants does not list it for Palm Beach County but a colony is present on the grounds of the West Palm Beach headquarters of the South Florida Water Management District, where I work, and it has persisted for at least a decade as a weed in the garden of a friend in Lake Worth. Although Florida has been well botanized, it isn't particularly difficult to find new county records and, in the case of Euphorbia heterophylla, finding the new Palm Beach County record was as easy as going to work or visiting a friend's garden.

Euphorbia heterophylla - Poinsettia heterophylla
Euphorbia heterophylla (synonym: Poinsettia heterophylla).

Just a short distance westward from the mowed roadside, in wet depressions that paralleled the west side of U.S. Route 27, there were colonies of the state-listed endangered plant, Lippia stoechadifolia. In places, the colonies extended for thousands of yards and one would scarcely think that it was a particularly rare plant. The genus Lippia closely resembles Phyla but Lippia species have at least some stems that are erect or ascending and become woody with age. In contrast, Phyla has creeping stems, none of which ever become erect and woody.

Lippia stoechadifolia
Lippia  stoechadifolia (synonym: Phyla stoechadifolia) is a state-listed endangered plant recorded only from Broward, Collier, and Miami-Dade counties.

close-up of the flowers of Lippia stoechadifolia
Close-up of the tiny flowers of Lippia stoechadifolia.

Many typical native plants of wet ground were growing with Lippia stoechadifolia but especially notable was Pluchea baccharis (synonym: Pluchea rosea). I had never seen such large, healthy, robust specimens and the dark pink to maroon-pink flowerheads made a pleasing contrast to the whitish upper leaves and bracts of the inflorescences.

Pluchea baccharis
Pluchea baccharis (synonym: Pluchea rosea), formed large freely flowering plants at this site.

Go to Part 1 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

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'
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
Spirodela polyrhiza, common duckweed.

Adrovanda vesiculosa - Waterwheel plant
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 - Whitetop Pitcher Plant
Sarracenia leucophylla, the whitetop pitcher plant.

Sarracenia catesbaei
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.

white-flowered Ixora hybrid
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

Monday, September 2, 2013

Yellow Flatsedge – Cyperus croceus

Cyperus croceus - Baldwin's Flatsedge - Yellow Flatsedge
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.

Cyperus croceus - Baldwin's Flatsedge - Yellow Flatsedge
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.

Cyperus croceus - Baldwin's Flatsedge - Yellow Flatsedge
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.

Cyperus croceus - Baldwin's Flatsedge - Yellow Flatsedge

Images and text © 2013 Rufino Osorio