LIII. ERICACEÆ.
Trees or shrubs, with scaly buds, and alternate simple leaves, without stipules. Flowers perfect, regular; calyx 4—5-lobed; corolla hypogynous, 5-lobed (of 4 petals in Elliottia), the lobes imbricated in the bud; stamens hypogynous, mostly free from the corolla, as many, or twice as many as its lobes; anthers introrse, 2-celled, opening by terminal pores, often appendaged; ovary 4—10-celled (inferior in Vaccinium); styles terminal, simple, stigma terminal; ovules numerous, anatropous or amphitropous; raphe ventral; micropyle superior. Fruit capsular, drupaceous, or baccate. Seeds with fleshy or horny albumen, embryo small; cotyledons small and short.
The Heath family with seventy-one genera is widely distributed over the temperate and tropical parts of the earth’s surface. Of the twenty-one genera found in the United States seven have arborescent representatives.
CONSPECTUS OF THE ARBORESCENT GENERA OF THE UNITED STATES.
Ovary superior. Corolla of 4 petals; flowers in erect racemose panicles; leaves deciduous.1. [Elliottia.] Corolla gamopetalous, 5-lobed. Fruit capsular. Capsule septicidal, the valves in opening separating from the persistent placentiferous axis; calyx-lobes imbricated in the bud; leaves persistent (sometimes deciduous). Flowers in terminal clusters; corolla 5-lobed; inflorescence-buds conic, covered with closely imbricated scales; leaves revolute on the margins.2. [Rhododendron.] Flowers in axillary clusters; corolla saucer-shaped, with a short narrow tube and 10 pouches below the short limb, the anthers in the pouches in the bud: inflorescence-buds elongated, covered with loosely imbricated scales; leaves flat.3. [Kalmia.] Capsule loculicidal, the valves in opening bearing the partitions and separating from the persistent placentiferous axis; calyx-lobes valvate in the bud. Capsule ovoid-pyramidal; flowers in terminal panicles of secund racemes; anther-cells opening longitudinally from the apex to the middle; leaves deciduous.4. [Oxydendrum.] Capsule oblong; flowers in axillary fascicles; anthers opening below the apex by 2 oblong pores; leaves persistent.5. [Lyonia.] Fruit drupaceous; flowers in terminal panicles; anthers bearing a pair of reflexed awns on the back, each cell opening at apex anteriorally by a terminal pore; leaves persistent.6. [Arbutus.] Ovary inferior; fruit baccate; flowers axillary, racemose or solitary; anther-cells terminating in tubular appendages and opening by terminal pores.7. [Vaccinium.]