The Little Sea Lavender that Could

 Sea lavender, Argusia gnaphalodes, is taking over my backyard. Its spread from a miserable, near leafless stick into a 15 x15-foot clump is impressive, to say the least. It's all-the-more worthy of admiration because it has survived storm surges from hurricanes Ian (2022), and Helene and Milton in 2024, without missing a beat.

The plant produces whorls of long gray-green, narrow, felty, slightly spoon-shaped leaves at the ends of its stems, which in time may grow upright, reach horizontally, or curve back down to the ground.  New leaves are held vertically, while older ones assume a more-horizontal posture, and still older ones hang down vertically. As the branch extends, lower leaves die, but still persist, giving the bare, dead-looking branches a sort of stark, unworldly presence.  Leaf-producing parts of the stem are pale yellow-green, while the older, lower stems turn gray or dark brown, and can look quite dead. New growth is soft, but older stems and branches are hard and brittle.  As the stems grow, they may shade out those below them, leading to gaps. This is more pronounced on the north-facing side of the plant. The other sides are more compact, so the across-canal neighbors have a fuller, tidier view than I do. 

 I liked the way the lower branches drooped and curved to make a series of "secret" rooms - great hiding places for small animals - including small children. I think of the forts we could have made way back when. For a long time a mockingbird took advantage of the shelter - foraging on the ground nearby and darting under the branches when it felt threatened. But now it's looking pretty unkempt on "my" side, so I really have to do something to restore it to the insanely beautiful shrub it used to be. It's gotten so big that it keeps me from checking the seawall, and is blocking access to an electrical outlet.

 

 

 When I first set out to impose some discipline I found myself loathe to lop. One branch had too many flowers to discard, while another was full of buds, and yet another was just too plain pretty. Also, I don't have the heart to punish something that is so obviously suited to the climate of coastal SW Florida, which is horticulturally inhospitable to so many plants. It's not blooming much now, so I am forcing myself to be hardhearted enough to prune even the less bedraggled parts.

The leaves are so densely hairy that they look quite different according to the light and time of day. In the soft light of late afternoon they take on a distinctly blueish cast. On overcast days they are gray-green. In direct sunlight they can be blindingly silver. They are nearly impossible to photograph with a point-and-shoot camera in full sunlight because the reflection makes the shot over-exposed.

 

Argusia with Opening Flower Buds

It flowers and fruits throughout the year, but most heavily in fall, winter and spring. The flowering arrangement (inflorescence) in botanical terms is a "helicoid cyme." The tightly curled developing inflorescence looks a little like a fern fiddlehead. The inflorescence gradually unfolds as the buds mature and bloom. Flowers are white, and with age develop purplish coloration in their throats. They are very faintly fragrant. The common name, "sea lavender," comes from the similarity to lavender leaf color, not the fragrance. Immature fruit is yellow-green. It turns black or brown as it ages. Fruits are a hard dark, dry structure called a schizocarp.

The singular habit and beauty of Argusia gnaphalodes makes it not one of my favorite native plants, but one of my favorite plants, period. A lot of new gardeners in south Florida experience great frustration.  It's too bad most of them aren't aware of the beauty and practicality of many native plants, and remain frustrated in their attempts to overcome insect and disease problems afflicting many popular exotics. Many of these plants are unsuited to south Florida's drastic rainfall fluctuations and either drown in the summer while they need extensive irrigation in the winter. Argusia gnaphalodes would not thrive in areas of south Florida with poor drainage, but there isn't a better choice for a dry, sandy site with little organic material.

 

 

 

 

 

Florida Fishpoison Tree

 Piscidia piscupula, the Florida fish poison tree, Jamaica dogwood, or fishfuddle tree, is a tropical hardwood native to south Florida and the Keys, the West Indies, Bahamas, and parts of Central America and Mexico. It is semi-deciduous, ie - shedding its leaves quickly, remaining bare only for a short time  before pushing out new growth. Flowers appear on bare or nearly bare stalks. It hit its flowering peak in the last week of May, and first week of June this year. 

Piscidia piscipula in bloom; 
edge of Johnson Bay, Isles of Capri, FL

The name "Jamaica dogwood" refers to its use in boat building. South Florida naturalist Roger Hammer reports that "dogs" are spikes or bars used as fasteners in ship construction. The flowers certainly don't look anything like the dogwoods most North Americans know. The wood is very  hard and apart from boats, is used for wood carving, fence posts and charcoal. 

Flowers

Typical "pea" flowers are borne in elongated clusters (racemes), and appear before, and sometimes overlapping with the year's new growth. Under magnification, they are hairy, especially the cup-like calyx, which appears to be a soft grayed lavender, like a mole's skin, due to the tiny hairs. Parts of the flower itself also bear silky hairs that are pressed flat on their surface. Flower color can vary quite a bit, from white tinged with pink or lavender, to red, to muddy gray. Like other members in the family, they attract a lot of pollinators, especially bees.

The bark and leaves contain rotenone, among other chemicals, and when tossed in the water, stun small fish, which float to the surface and can be harvested, hence the name "fishpoison." This practice is illegal in Florida, though we've reached such a state of general ignorance that I doubt anybody under 60 even knows the trick. 

Rotenone supposedly doesn't harm warm-blooded animals, but the plant contains plenty of other substances that do. Dried root bark is used  both internally and externally in folk medicine to relieve pain and insomnia to the point of unconsciousness, and to treat nervous disorders and skin ailments, but the plant's toxic/medicinal potential remains largely uninvestigated. Dried extract is available on the Internet, but I don't plan to play lab rat myself! For one thing, there seem to be no generally accepted dosage guidelines, but plenty of warnings.

The tree, which can reach 30-50 feet tall, with a broad, spreading crown, can make a striking specimen where it is not crowded. In shade and  competition from other plants it stays pretty spindly and unimpressive.  Osorio calls it "underutilized" in the Florida landscape. A sucking insect, the Jamaica Dogwood Psylla, occasionally can make the leaves unsightly, but again, acccording to Roger Hammer, doesn't make it undesirable in the landscape. It is highly drought tolerant once established, and grows behind the dune line on beaches, and in sand, rocky or gravelly soil elsewhere. Rather than falling over in storms, it tends to lose branches. 

Multi-trunked specimen,
Parking Lot, Collier-Seminole State Park
Collier County, FL

What first may appear to be leaves are actually leaflets. Like other members of the family, the fishpoison tree has compound leaves. They alternate along the branch, and typically have 4-8 pairs of leaflets plus a single terminal leaflet. The leaflets can vary in shape from more or less oblong to more oval, and the tips can be blunt, rounded or even pointed. They are fairly leathery on  top, and hairs  can give the underside a velvety feel. The leaves appear near the end of the flowering period. Leaves and individiual leaflets in the subfamily Faboidae, to which Piscidia piscipula belongs, are characterized by a swollen structure where they join the petiole or stem, called the "pulvinus." The leaves are a dark, matte green on top, and a lighter, softer shade on the underside. Varying pressure levels within the pulvinus cause the leaves and leaflets to fold up, seemingly at nighttime, but studies have shown that this is a biological rhythm not triggered by light levels. 

Piscidia
3 Mature Leaves; 3 Emerging Leaves

Members of Faboideae also are associated with the famous "nitrogen-fixing" bacteria, varioius species of Rhizobium. These symbiotic soil organisms "infect" root hairs of certain plants, especially members of Faboideae, where they transform atmospheric nitrogen into an ammonium form that can be used by the plant to produce plant protein. In turn, the bacteria gain carbohydrates from the host plant. Usually each Rhizobium species is limited to a single host species. Such complexity is probably one reason supposed "restoration" projects may fail, for replanting alone is a pretty simplistic approach. 

Black seeds are borne in a papery winged structure that passes from pink, green, yellow to brown. The tree apparently will grow readily from seed, as well as cuttings, so readily, in fact, that limbs used for fence posts make take root!

Seed Pods

The native Cassius Blue butterfly and the black and silver Hammock Skipper use the leaves as larval hosts. 

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I have relied heavily on the following sources for this article:

Roger Hammer. Florida Keys Wildflowers. Falcon. 2004. p.177. Email conversation.

Rufino Osorio. A Gardener's Guide to Florida Native Plants. University Press of Florida. 2001. pp. 265-6.

J. Paul Scurlock. Native Trees & Shrubs of the Florida Keys. Laurel Press. 1987, p. 123.

Wendy B. Zomlefer. Guide to Flowering Plant Families. University of North Carolina Press. 1994. pp. 160-166.