Rivina

It's been too windy for the past weeks for comfortable outdoor sketching, but  at least I managed some quickies of rouge plant, Rivina humilis, a delicate understory shrub. I always think of bright green and red as Christmas colors, and this year Rivina delivered. As of Jan. 1, 2019, it is still flowering.

Rivina humilis - in Aquabee 93 lb sketchbook

As the species epithet "humilis" indicates, rouge plant is low-growing. Some of my sources have it reaching 5 feet, but I've never seen one taller than 3 feet. The stem is woody, while the branches can be spreading and almost vine-like. Especially in deep shade, the branches droop over and around surrounding vegetation - as though they were too delicate to support themselves.

My plant is a semi-volunteer, growing in the dappled sun/shade under a medium-sized Simpson's Stopper. It is the offspring of a plant that languished and ultimately died in a nearby pot. It's present spot is pretty good for it in terms of sun and shade, but it is exposed to north winds, which it doesn't like. A week or so back we had 2-3 days of unusually strong sustained winds accompanied by even stronger gusts. The wind in combination with chilly temperatures bleached the edges of many leaves.

Rivina used to be included in the Pokeweed family, Phytolaccaceae, but is now classified in its own family, Petiveriaceae.

It is a very ornamental plant. The leaves are alternate. (New branches arise in the angle between an existing leaf and branch. This new growth can be so compressed, with branching upon branching, that it is next to impossible to tell what is going on with leaf arrangement. At least it is for me).  The leaf has slightly undulating margins and a smooth surface. The leaves are fairly squared off at the base, and pointed at the tips. The petioles can be quite long, and are gently hairy.

The flowers appear along a terminal spike, or raceme. They are only about 5mm in diameter, and lack petals. What looks like petals at first glance is actually 4 sepals, either pink or white. The fruit is a bright red, which has been used for dyes. The berry contains 1 black seed. Flowers and berries  can appear along the same stalkat the same time.

Despite its delicate appearance, Rivina is reasonably tough, growing in hammocks on the backside of the sand dunes, hammocks farther inland, and in disturbed sites. Most Florida natives are equipped to endure long periods of winter drought, but this plant likes a little moisture to look its best. It will flower and fruit in full shade, and doesn't thrive in unmitigated sun.

According to the USDA Plants Database, Rivina is native to Florida, Mississippi, Louisiana, Texas, Oklahoma, Arkansas, Missouri, New Mexico and Arizona. It also is native to the Caribbean, Central America, and tropical South America. It is widely naturalized in the Pacific islands, including Hawaii and the Galapagos, and has spread to Australia and Asia as well. In some areas it has become an invasive pest.

Rivina is an important food plant for birds, and the berries do not last long in our yard.

-----------------------
Blooming now: Dune Sunflower, Heliotropium, Blue Porterweed, Scarlet Sage, Pityopsis, Rivina, Blue-eyed Grass, Elliott's Aster, Tickseed, Bacopa, Bidens, Goldenrod, Gaillardia. Non-natives: Emilia, Scarlet Milkweed, Bougainvillaea, Dauben Waterlily, Tina Waterlily, Pentas, Marigolds, Blue Sage, Blue Daze.