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.

 

 

 

 

 

Sea Lavender

The first time I saw sea lavender, Argusia gnaphalodes, was somewhere in the Caribbean, possibly Grand Cayman, or Aruba, over 30 years ago. The beauty of its green-gray whorls of silky soft leaves so impressed me that I pinched off a tiny piece and showed it to the agricultural customs agent at Miami International Airport. He identified it for me, and explained that it once had been common along Florida east coast beaches, but was becoming increasingly rare due to development. (Environmental laws give Florida's wetland plants some protection. But some of the most rare and vulnerable native species require high and dry land, precisely the sites most coveted by developers, and often come out the losers).

Argusia gnaphalodes - Tip of Stem

After moving back to Florida in 1990, I began looking for the plant - in vain. So far my sources disagree on whether the plant occcurs naturally on the state's sw coast. Next year I will be stalking local state park and public beaches in search of it. Otherwise, it is native to Florida's east coast north to Brevard County, the Keys, West Indies, Yucatan Peninsula, and the Caribbean coast of central America and Venezuela. 

 Finally, about 2 years ago, I discovered a row of scraggly and generally unimpressive pots of Argusia at the All Native Plant Nursery in Fort Myers*, and pounced. Over the last 2 years it has become a handsome, fully-leafed out shrub about 3-and-a-half feet tall and wide. Barring calamity, it will keep spreading, though perhaps at a slower pace.

Argusia gnaphalodes  - Front View

I planted it in March, several months before the advent of the rainy season. I watered it well for the first week or so, until it seemed to be doing fine on its own, and since then I have neglected it completely, even though it is growing in one of the most difficult areas of our yard - a south-westerly slope of pure sand and brutal daylong sunshine. The summer rains no doubt were crucial to its establishment. 

In fact, gardeners living farther inland, where drainage is not so severe, and salt-laden wind not so common, might have trouble cultivating sea lavender, because it cannot take saturated or highly organic soils. It might also be subject to mildews and molds further inland, where there is less wind - speculation on my part, but possible.

(I have found transplanting native plants during the fall risky. I don't think the plants are programmed to grow in the absence of sustained rain, and stay in a semi-dormant state either until they die or the summer returns. No amount of watering seems to compensate for regular, saturating showers).

Like many plants in the Borage Family, Argusia gnaphalodes is extremely hairy everywhere except the petals and fruits. A dense covering of flattened hairs protects the succulent leaves from dehydration, too much sun and salt. It also gives them the silky softness of a puppy's ear. The leaves reflect silver in bright light, so much so that it's easy to overexpose photographs. In lower light, the plant can appear quite blue. 

Older Flowers - Low Light

Arg-The Latin root of the genus name, Argusia, refers to bright or silver light. The species name derives from a superficial resemblance to a genus of weedy winter annuals in the Aster Family, Gnaphalium.  

The leaves, flat, slightly succulent, and a little spatula-shaped, alternate around the stem, and terminate in a dense whorl. They are about 3-4 inches long and one-quarter inch wide. As the stem elongates, lower leaves die, but don't fall off immediately. Eventually the bottom third of the plant will show these bare stems. The habit may not be to everybody's taste, but I think it makes the plant more interesting. Pendant stems can root, which makes Argusia an important dune-stabilizing plant. 

Backside of Plant - One Stem Starting to Droop

The flowers are formed in a tightly wound cyme, which straightens as the blooms mature. 5 petals, somewhat crinkled, are united at the base. Young flowers are white, with the centers turning pink-maroon as they age. They are said to be mildly fragrant, but so far I haven't been able to catch that. 

Young Flowers

Fruits start out yellow-green, and turn brown or black as they ripen. I haven't seen any ripe fruits yet, so I suspect something eats them before I notice,

Immature Fruits

One of the main reasons this gorgeous plant isn't grown more is that basically nobody knows about it, which is a shame, because for coastal landscapes, it's unbeatable. 

See my blog post, All Native Plant Nursery, April 9, 2020.