Sargent, Charles S. 1889. Vaccinium hirsutum. Gard. & Forest. 2: 364, 365, fig. 119.
Ericaceae
Species Description - Plants in dense and sometimes extensive colonies, 5-20 cm. high. (Twigs of the enrrent season green.) Leaves deciduous, green; the lower surface shining, non-glandular, glabrous (or rarely with some pubescence on the veins); usually narrowly elliptic, 0.4-1 cm. wide, 1-3 cm. long; the margin sharply serrate. Corolla cylindraceous, 3-5 mm. long, usually white. Fruit bright blue, 5-7 mm. in diameter, of excellent flavor.
Wlaccinium fissum Schranck, Denks. Bot. Ges. Regensb. 1: 15. 1818. (See discussion under species 11, V. brittonii.)
Vaccinium pennsylvanicum var. angustifolium A. Gray, Man. ed. 1. 261. 1848.
Vaccinium pennsylvanicutm var. alpinum Wood, Class-Book. ed. 1861. 483. 1861.
Vaccinium angustifolium var. laevifolia House, Bull. N. Y. State Mus. 243-244: 61. 1923. (The spelling later changed to laevifolium.)
Diploid (2n = 24).
This is the common commercial blueberry, or sugarberry, harvested exten- sively in the northeastern States and to some extent in Canada from fields which are "pruned" and kept weed-free by burning in alternate years, or every third year (fig. 7). The hybrids with myrtilloides are pubescent, especially along the veins, and sometimes subserrate; V. angustifolium var. myrtilloides House (not V. myrtilloides Michx.) appears to be this combination. Where it is common, and with opportunity for segregation, forms with glabrous entire-margined leaves can be found. There could, of course, be some argument whether these are entire- margined forms of angustifoliurm, or glabrous forms of myrtilloides; in any pre- cise system of nomenclature they would be neither, being the more-or-less extreme segregate and/or back-crossed forms of the hybrid combination. The hybrids with vacillans will be mentioned again under that species; as noted elsewhere (Darrow & Camp 1945), where the raniges of vacillans anld angustifoliutm overlap, the latter species is usually an ecological relic, or at least is not spreading to any great extent, the population being represented by residual colonies. Hence, the effect of gene-exchange is more noticeable in vacillans than in angustifolium.
The occasional "halfhigh" combinations produced by hybridizationl with either caesariense or atrococcum exhibit the usual' and expected intermediate and segregate morphological characters. Identification of such material in the field seldom causes any difficulty except where highbush tetraploids aind lamnarckii are also present and have produced their own set of halfhigh hybrids. It should also be kept in mind that the halfhigh segregates (either diploid or tetraploid) are physiologically capable of persisting under conditions which would exclude the ancestral highbush material; as a result, the halfhigh plants tend to spread from the zone of greatest concentration and are occasionally to be found mingled with the lowbush forms, sometimes at a considerable distance from their poilnt of origin. As a result, it is not always safe to assume that the halfhigh material is growing associated with its lowbush ancestor. In fact, because of their more conmparable size and closer balance of ecological requirements, the diploid halfhigh plants are more likely to be found associated with the tetraploid lamarckii than with the ancestral diploid angustifolium. Occasional extreme diploid segregates (pre- sumably also after repeated back-crossing) are known which morphologically approach V. angustifolium, but which still retain sufficient genetic material from the distant highbush ancestor as to be coarser than typical angustifoliutm, and so may be confused with the tetraploid lamarckii. These, however, are so rare as to be little more than biological curiosities and, even then, a detailed examination will usually reveal some character sufficient for placement.
Canada North America| United States of America North America|