Vaccinium amoenum Aiton
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Authority
Sargent, Charles S. 1889. Vaccinium hirsutum. Gard. & Forest. 2: 364, 365, fig. 119.
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Family
Ericaceae
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Scientific Name
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Type
Type locality: "North America" (probably South Carolina). Introduced at Kew in 1765 by John Cree.
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Description
Species Description - Plants suckering to form dense clumps, occasionally a meter or more in diameter at the base, or sometimes crown-forming, 1.5-2.5 m. high. Leaves deciduous, dark green or rarely slightly glauceseent; the lower surface bearing conspicuous glands, pubescent along the veins, or rarely glabreseent; obovate, or sometimes subelliptic, usually apically acuminate, sometimes abruptly so, 1.5-2.5 cm. wide, 4-5 cm. long; the margin sharply serrate. Corolla narrowly to broadly cylindro-urceolate, 10-12 mm. long, often deep pink. Fruit black or dark, 8-10 mm. in diam., usually "thick-skinned" and of unpleasant flavor.
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Discussion
Hexaploid (2n = 72).
Because of the distribution of V. amoenum, various segments of the ashei- coimplex have hybridized with it, and from this it has partaken certain aberrant characters, such as occasional plants with more pubescence than usual, or with some glaucescence. This latter aberrancy is notably true where the " australoid" plants of ashei are common, as in Georgia and certain areas of Florida.
This hexaploid appears to be the end of the tenellum (2x)-virgatunt (4x)- amoenum (6x) polyploid series, in which occasional pentaploids are also known. In the herbarium-if only the upper parts of the plants are present, and if ade- quate field data are lacking-these three sometimes offer some difficulties of identi- fication, in spite of the differences listed here (as, for example, if the material is collected just after flowering and before the leaves are fully formed). However, in the field, there is generally little trouble; where, by chance, the diploid, tetra- ploid; and hexaploid are growing together, they exhibit such marked differences in growth habit and size that there is no coufusing them (for the flowers, see figure 6). In fact, with but little experience, even the pentaploids can be recog- nized, for they occupy a logical niche between the tetraploids and hexaploids. No triploids have yet beeen found. It must be admitted that, at the margin of ecological tolerance, or under unusual conditions, plants will be found which cause some trouble in identification, appearing to be intergrades. It is for this reason that, formerly, terellurm has sometimes been considered merely a variety of virgaturm. If only these two were to be considered, there might be some justification for considering them as subspecies of a euploidion (for a discussion of this kind of species the paper by Camp & Gilly, 1943, p. 341, may be conlsulted). But the presence of the hexaploid complicates the picture for, certainly, there would seem little reason in including tenelUm and amoenum in the same species. It is for this reason that these three genetically disjunct and usually morphologically separable entities have been maintained as distinct species.
A specimen in the British Museum supposed to be the type of V. amoenunm has somewhat broader leaves than is typical for the bulk of the material. This specimen appears to have been prepared for the Banks Herbarium some years after the description was written and may not be from the saml-e plant which Aiton had originally. That was a period when English gardeners were unusually interested in American plants and many introductions were made. This speci- men, therefore, could have been from a later introduction, but labeled "V. amoenum." However, the specimen in the British Museum is apparently no more aberrant than some which have been included in the species in the present interpretation. Given a choice of forms, it is very likely that the original col- lector would have selected one with larger and better-flavored fruit-a form which would have been produced by some gene exchange with members of the "aus- traloid " segment of ashei and which, as may be noted in the discussion of V. ashei, are relatively common on parts of the southeastern coastal plain. Such a plant, while still to be assigned to V. amoenum, would have somewhat broader leaves than the genetically uncontaminated material.
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Distribution
South Carolina to northern Florida, west to Texas and Arkansas. Usually on uplands and in open woods; because of its light requirements, in heavily tim- bered country, or in brushy areas, it is more likely to be found along the margins of streams and lakes, or even in swamps.
United States of America North America|