The Mobile-Tensaw River Delta is host to many special plants. Among some of the rare plants known to occur in this area is the green-fly orchid, Epidendrum conopseum, the only epiphytic orchid known to occur in the state. Epiphytes are plants that grow on other plants, not as parasites, but using the host plant as a place to grow while getting nutrients from rain and dust. Green-fly orchid has been collected in only 10 counties in Alabama. It has been found growing in the swamps of the Mobile Delta and enjoys a diversity of hardwood tree hosts, including live oaks, southern magnolias, swamp tupelo, and bald cypress. Bottoms supporting this species are usually shaded and moist, allowing epiphytes to flourish.
Green-fly orchid may be more abundant than known records indicate. Small plants attached to the limbs of trees often escape notice, especially those camouflaged by resurrection fern, Polypodium polypoides, and Spanish moss, Tillandsia usneoides. Green-fly orchid blooms in July. The scientific name Epidendrum means “tree-dweller” and conopseum means “gnat-like”.
The southern rein orchid, Platanthera flava, is another engaging orchid found in the Delta, usually blooming in May. This tiny orchid is typically found in wet and frequently shaded situations. The southern rein orchid is found over most of the United States east of the Mississippi River drainage except south Florida. After pollination, the ovaries of this species swell quickly, well before the flower begins to wilt. At this time each yellowish-green southern rein orchid flower appears to be growing from an oval jade vase.
Tiny-leaved buckthorn, Sageretia minutiflora, one of the rarest shrubs in the United States, is also known to occur in the delta. Its specific habitat is found on and around the calcareous shell mounds in the Mobile-Tensaw Delta, as well as on Little Dauphin Island and Dauphin Island. This shrub blooms in September and has very fragrant flowers.
The rare sarvis holly, Ilex amelanchier, has been reported from only 3 counties in Alabama, Mobile, Washington and Baldwin. It occurs in woodlands astride creeks, river floodplain forests and cypress-gum swamps. It is found in the sub-canopy under red maple, tupelo gum and cypress. Sarvis holly is a difficult plant to locate when not in fruit, especially after losing its leaves. It is one of the rarest hollies in the state.
Loblolly bay, Gordonia lasianthus, not to be confused with sweetbay, Magnolia virginiana, which is also called bay, is found only in Baldwin, Covington, Geneva, and Mobile counties in Alabama. Loblolly bay is found in swamps, bogs, hammocks and bays along the southern coastal plain, from southern Virginia, west to Louisiana, and south to Lake Okeechobee in peninsular Florida. The flowers are fragrant, showy and white, about two to three inches across, and are open in midsummer for a period of several weeks. The loblolly bay is botanically related to the tea plant of Asia. This tree is a beautiful evergreen, growing up to 70 feet in height, with leathery oblong leaves that are dark green above and paler below.
Rare Plants of the Delta
Scientific Name Common Name
Acorus americanus sweetflag
Brachiaria platyphylla broad-leaf signalgrass
Canna flaccid golden canna
Celtis iguanaea iguana hackberry
Cleistes divaricata rosebud orchid
Coreopsis gladiate coastal plain coreopsis
Epidendrum conopseum green-fly orchid
Gordonia lasianthus loblolly bay
Hibiscus coccineus scarlet hibiscus
Hypericum nitidum Carolina St. John’s-wort
Ilex amelanchier sarvis holly
Juncus gymnocarpus naked-fruited rush
Kalmia hirsute hairy laurel
Ludwigia arculata piedmont seedbox
Lygodium palmatum American fern R
Orobanche uniflora one-flowered cancer-root
Panicum nudicaule naked-stemmed panic grass
Piers phillyreifolia climbing fetter-bush
Pinguicula primulifolia southern butterwort
Pinguicula planifolia Chapman’s butterwort
Plantanthera flava southern rein orchid
Plantanthera integra yellow fringeless orchid
Ponthieva racemosa shadow-witch
Populus heterophylla swamp cottonwood
Potamogeton robbinsii Robbin’s pondweed
Rhapidophyllum hystrix needle palm
Rhododendron austrinum orange azalea
Rhynchospora crinipes hairy-peduncled beak rush
Selaginella ludoviciana Gulf spiked-moss
Xyris drummondii Drummond’s yellow-eyed grass
Xyris scabrifolia Harper’s yellow-eyed grass