Synonyms

Vitis rotundifolia Michaux (Flor. bor. amer., II, p. 231); V. vulpina Linné, Torrey et Gray, Engelmann; V. muscadina, angulata, verrucosa, callosa, hyemalis, cordifolia, acerifolia, peltata, vulpina Rafinesque (Manual of grape vines); V. taurina Bartram; V. vulpina var. rotundifolia Regel; V. vulpina Clayton. Local names: Southern Muscadine, Muscadine, Bullace Grape, Bullet Grape, Fox Grape du Sud.

Historical and Geographical Overview and Ecology

The species was specified by Michaux. It was known to Linnaeus under the name V. vulpina, but Michaux's nomenclature was preserved by J.-E. Planchon to avoid confusion between this species and V. riparia.

The geographical range covers the southern states of the US Atlantic coast: from northern Florida to Virginia in the northeast, and from Florida to south-central Texas (Houston) on the coast of the Gulf of Mexico through the territories of Alabama, Mississippi, and Louisiana. The species advances minimally in the northwestern and western directions; isolated wild individuals have been recorded in Arkansas, eastern Tennessee, and Mexico (Xalapa, Perote, Mirador).

Ecological requirements are characterized by strict confinement to deep, rich, and humid sandy soils. Optimal development is achieved under conditions of high temperatures, elevated soil moisture, and atmospheric humidity. The species occurs exclusively on alluvial riverbanks and in sandy, almost always swampy lowlands of the Atlantic coast. On Roanoke Island, a wild specimen was recorded covering an area of approximately 1 hectare and yielding up to 90 hectoliters of wine in a single year.

Agrobiological and Cultural Characteristics

In commercial vineyards of North Carolina, the vines are planted spaced at 9 or 10 meters in all directions. Pruning of the vines is not practiced; within 10 to 15 years, the vegetative mass completely covers the allocated area. The main horizontal branches form numerous thin, filiform adventive roots that hang toward the ground and are protected at their apex by a very thick blackish calyptra; some of them take root.

Introduction into Europe yielded no practical viticultural results due to weak vegetative vigor. The species requires highly fertile soils, a very hot and humid climate, fails to propagate from cuttings, and demonstrates biological incompatibility when grafted with European grapevine varieties. Cases of successful grafting of European scions onto V. rotundifolia are exceptional, and the graft union persists for no more than one year, which is explained by the differing anatomical organization of the phloem in Muscadinia and Euvitis. In calcareous soils, resistance to chlorosis is completely absent.

The species is characterized by maximum resistance to cryptogamic diseases and phylloxera, reaching complete immunity.

Technological Properties

The crop is characterized by irregular ripening of berries within small clusters, necessitating successive selective harvests. The harvesting method consists of vigorously shaking the vines, causing the ripe berries to fall onto sheets spread upon the ground. The berries are low in sugar and acid content; consequently, the musts of V. rotundifolia are chaptalized and fortified. In the United States, they are generally converted into sweet liqueur wines of very poor quality, and occasionally into sparkling wines.

Systematics and Anatomo-Morphological Characteristics

V. rotundifolia forms the type of the subgenus Muscadinia, characterized by its lenticellate bark, the absence of a shedding rhytidome, simple tendrils, canes without nodal diaphragms, adventitious roots, and ruminate seeds.

The anatomical features distinguish it clearly from true grapevines, notably by the tangential arrangement of secondary phloem fibers in bundles parallel to the medullary rays. The stomata are small, the spongy tissue of the leaves consists of four layers of nearly regular cells, the medullary rays are narrow, and the starch grains possess thick membranes.

Morphological Description of Organs:

  • Vine (Trunk): Very vigorous, with a spreading, climbing habit; trunk very strong with hard wood. Bark dark brownish-black, composed of fine, tightly adherent interwoven strands. Trunks measuring from 1.00 to 1.60 meters in circumference are not uncommon.
  • Buds: Small, enclosed by dark brown scales, with few and short hairs.
  • Young Leaves: Spreading early, covered on both surfaces with a whitish down, which is reddish on the veins of the lower surface; margins feature well-defined, translucent teeth.
  • Flowers: Small, ovoid or globose, dull and non-odorous; calyx entire, relatively developed; corolla always opening as a calyptra that persists on the flower for some time. The disk is entire, forming a brown crown at the base of the underdeveloped ovary, surmounted by a long style and terminating in a narrow, unlobed stigma (Fig. 624, Fig. 625, Fig. 626).
  • Canes (Shoots): Slender, long; nodes barely apparent on the straight, cylindrical cane. Secondary branches are few, long, and slender (short when fruitful). Light green in the herbaceous state, turning dark gray and shiny upon lignification; bark provided with numerous small grayish lenticels. The phellogen layer is subepidermal. The wood matures early, being hard and dense, and whitish-green internally. Medulla (pith) thin, occupying at most one-fifth of the cane thickness, dense, whitish, continuous throughout the entire length of the shoot, slightly wider at the nodes where diaphragms are completely absent. Internodes short, with well-defined though wide striations (Fig. 629).
  • Tendrils: Discontinuous, slender, short, simple.
  • Leaves: Small or medium-sized, as wide as they are long (generally 7 to 10 cm). Form quadrangular or pentagonal; entire, the terminal lobe indicated only by two more developed lateral teeth. Leaf blade flat and smooth, rather thick, parchment-like. Petiole sinus deep, square U-shaped or very open and shallow V-shaped, continuous on its margins. Teeth generally in two series, wide and relatively long, acute, concave on their margins, with their general direction oriented obliquely toward the terminal lobe; mucron barely indicated. Main veins thin but prominent on both surfaces. Upper surface rather dark green, glabrous and shiny; lower surface a lighter green, more varnished, with a few short, brush-like hairs at the insertion of the secondary veins onto the main ones. Petiole long, slender, with a few small tufts of short hairs, forming an obtuse angle with the plane of the leaf blade.
  • Clusters and Berries: Cluster small, composed of a few berries. Peduncle short, dull green; pedicels short, with a large, slightly verrucose torus. Berries large, spherical or slightly ovoid, detaching from the cluster as they mature, pruinose, most often yellowish-brown at complete maturity, rarely dark violaceous-red; skin very thick, hard and elastic, coriaceous and harsh; pulp fleshy, with a flavor that combines sweetness and harshness.
  • Seeds: Numbering two or three per berry, large, elongated (9 mm long by 5 mm wide) and relatively uniform in length, trigonal or flattened, often asymmetrical, dark chocolate-brown, with a brick-red tint in the depressions of the face and the pits. Chalaza rudimentary and raphe absent; replaced by an oval depression located at the center of the seed, from which very distinct radiating striations originate, along with two longitudinal grooves running toward the beak and the bilobed base of the seed (Fig. 627, Fig. 628).

Selection and Hybridization

The cultivated variety composition has been formed through the selection of wild forms and seed propagation. These varieties retain a constant, distinct ampelographic physiognomy of the species, differing only in the color of the fruits. Among them are: Scuppernong, Mish, Thomas, Tender Pulp, Flowers, Richmond, Pedee.

Experiments by A. Millardet and de Grasset proved the possibility of reciprocal fertilization between Muscadinia and Euvitis. However, in the hybrids obtained, the absorption of characteristics by one species (especially by Euvitis) was always complete; Millardet classified these organisms as false hybrids. T. V. Munson obtained two confirmed hybrids from the cross of V. rotundifolia × V. lincecumii (varieties La Salle, San Jacinto).