Prunus alabamensis

Prunus alabamensis, the Alabama cherry or Alabama black cherry, is an uncommon or rare species of tree in the rose family endemic to parts of the Southeastern United States. It occurs in the states of Alabama, Florida, Georgia, Mississippi, and South Carolina. It is closely related to and found wholly within the range of Prunus serotina, the black cherry, a much more common and widespread species of Prunus that is also native to the region. Alabama cherry is sometimes considered to be a variety of Prunus serotina (P. s. var. alabamensis), however most authors treat it as a distinct species.

Description
Alabama cherry is a deciduous  flowering plant in the rose family endemic to the Southeastern United States. It is similar to but distinct in morphology from the closely related Prunus serotina.

Form
Alabama cherry is a small or medium sized tree growing to heights of 20–40 ft  and a diameter of about 6 in, scarcely exceeding 25–30 ft in height.

Bark
The immature bark is gray and smooth; mature bark is rough and becomes broken into plates that are dark-gray to black in color. Young shoots or twigs are green and pubescent,  often densely so, with rusty-brown hairs.

Leaves
Leaves are alternate; ovate to elliptic in shape; rounded or slightly narrowed at the base; usually obtuse, rounded, or emarginate at the apex, but sometimes short acuminate, abruptly acute, or acutish; 3–12.5 cm in length and 2–6.5 cm in width; with petioles that are 2–12 mm long. Margins are bluntly serrated with appressed teeth that have glandular tips. The upper surface of the leaf is dark green and the lower surface is a lighter green. The lower surface is uniformly but sparsely pubescent with rusty-colored hairs that are longer and more dense along the midrib but not conspicuous; axils of veins lack tufts of hair entirely; veinlets are prominent. The texture of leaves is leathery. In autumn, leaves turn a red or orange color.  

Flowers
Flowers grow from the axils of leaves on elongated racemes that are 4–6 in long. Flowers have 5 small, white petals, and the rachis, peduncles, and calyx are pubescent.  Flowering occurs from April to May. 

Fruit
The fruit is a small reddish, dark purple, or black, globose drupe, about 10 mm in diameter.  Fruiting occurs from June to August. 

Habitat and range
Alabama cherry is rare to uncommon within its range. It grows in mixed oak-pine-hickory forests in sandy or rocky dry woodlands, on rocky slopes and sandhills, and on the summits of low mountains, often associated with the longleaf pine (Pinus palustris). It grows at elevations of 20–700 m.  It is known to occur in the states of Alabama, Florida, Georgia, Mississippi, and South Carolina,

Relation to Prunus serotina
Alabama cherry is sympatric with its close relative Prunus serotina, occurring wholly within its natural range and being similar but morphologically distinct from it. They are easily distinguished from each other by the differences of their leaves and inflorescences.  Alabama cherry is sometimes considered to be conspecific with P. serotina; that is, a variety or subspecies of P. serotina rather than its own species. Plants of the World Online and Flora of North America, as examples, classify it as Prunus serotina var. alabamensis (C. Mohr) Little, but local botanical authorities and most authors classify Alabama cherry as its own distinct species,  including the Alabama Herbarium Consortium, the University of West Alabama, and Auburn University; the Global Biodiversity Information Facility also lists Prunus alabamensis (C. Mohr) as being the accepted name for this plant. Phylogenetic analyses have been done on Alabama cherry to determine if it is a genetically distinct species. A 2013 analysis found no clear genetic distinction between P. s. var. serotina from Alabama and P. alabamensis,  however a following study in 2017 determined that P. alabamensis and P. serotina are indeed modestly genetically differentiated and either frequently exchange genes with each other or do not exchange genes and have only recently diverged. The study also suggested that future research should investigate what underlying factors are maintaining the phenotypic distinctiveness between the two species. 

Edibility and toxicity
The fruit and seed are edible and can be eaten raw or cooked, however caution should be taken when consuming the seed as this plant belongs to a genus where most or all species produce the volatile toxin hydrogen cyanide, mostly in their leaves and seeds. Levels are usually too small to do any harm, but especially bitter fruits or seeds should not be eaten.

Other uses
Green dyes can be obtained from the leaves and fruits.