Beech Family (Fagaceae)

A nut fruit partially enclosed in basal bracts (acorn, devastated to near extinction by chestnut blight, caused beechnut, chestnut) is the most familiar characteris- by an ascomycete fungus, Endothia parasitica (see 48); tic of this family of eight genera. Genera are Fagus sudden oak death is a disease caused by Phytophthora (beech), Castanea (chestnut), Quercus (oak), Litho- ramorum, an oomycete (see 46). carpus, Nothofagus, Castanopsis, Trigonobalanus, and Chrysolepsis. Fossils indicate an origin during the mid- Quercus spp. Oaks dle of the Cretaceous. Oak forms vary from small shrubs to large trees. They Alternate, simple leaves have lobed, toothed, or entire have deep roots and occur in dry sites. There are over margins and deciduous stipules. The flowers are usu- 400 species and many hybrids between species. Oaks ally unisexual and wind-pollinated. are easily identified, even in winter, by the cluster of buds (a) at the end of the stem (c). The leaves (e, f, g) The male flower occurs in catkins or singly and has 4–7 are deciduous or persistent. Young oaks tend to retain sepals, 4–40 stamens, and a vestigial pistil. The female their leaves over winter and shed them in spring. flower can be single in a cup of bracts or in a cluster of 2–3 flowers, which may have bracts. Fused sepals of the Oaks are divided into two groups: white oaks and red female flower have 4–6 lobes. The pistil has an inferior oaks. White oaks have leaves with rounded lobes and ovary of 3–6 carpels, chambers (locules), and styles. acorns that mature in the autumn of their first year. Red Two ovules occur in axil placentation. They develop in oak leaves have bristle tips and acorns that mature in each chamber, in which one develops and the other the autumn of the second year. aborts. Oaks are monoecious with separate male and female Of interest...hardwood lumber: Castanea spp. flowers on one tree. Male flowers form in pendant clus- (chestnuts), Fagus spp. (beeches), Quercus spp. (oaks; ters, an indication of wind pollination. The male flowers in the United States, oaks are the second most im- (h) open before or with expanding leaves (k). The male portant source of lumber after conifers); food: nuts flower has four to seven sepals (m) and six to twelve of chestnut, beech and oaks. Native Americans used stamens (n). acorns to make bread. Acorns are also an impor- tant source of food for wild animals and birds. Com- The female flowers form in the axils of new spring mercially, Castanea sativa (sweet chestnut), of south- leaves. This flower has joined sepals of 6 lobes (o) and ern Europe, is a source of nuts for purees, stuffings a pistil consisting of 3 styles (p) and 3 stigmas (q). The and stews; cork: bark of Quercus suber (cork oak) is ovary is enclosed in a whorl of bracts (involucre,r) stripped and dried to produce cork; ornamentals: Cas- which matures into a scaly cup (s). The fruit of cup and tanea spp. (chestnuts), Fagus spp. (beeches), Litho- nut (t), commonly known as an acorn, may mature in carpus (tanoak), Quercus spp. (oaks); plant diseases: one or two seasons. Castanea dentata (American chestnut) has been

COLOR CODE tan: buds (a, b), leaf scar (d), leaf (g), cup (s) brown: stem (c), peduncle (l) green: leaf (e) red: leaf (f) yellow: male flowers (h) light tan: stem (i), sepals (m), nut (t) tan-orange: bud scales (j) grey-green: young leaves (k) yellow-green: stamens (n) light green: sepals (o), styles (p), stigmas (q), involucre (r)

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