Description:

• Evergreen trees up to 12 m high, young shoots terete or slightly oval in transection, glabrous
• Leaves opposite, decussate, simple, coriaceous, margin entire, rolled under; ± sessile when young, petiolate later; stipules rudimentary, very small, lateral, marcescent
• Inflorescence a multifloral panicle, mainly terminal; bracts usually caducous
• Flowers bisexual, regular, hexamerous
• Sepals 6, white and petal-like, recurved, valvate and distinctly beaked in bud, persistent; hypanthium (calyx tube) short
• Petals 6, free, arising on rim of hypanthium and alternating with sepals, conspicuously and narrowly clawed, recurved, fragile, fugacious; limb ± orbicular, margin lacerate, hood-like and covering anthers in bud only
• Stamens 6, antepetalous, arising near inner rim of hypanthium; filaments ± terete; anthers sub-basifixed, versatile, 2-thecous, 4-sporangiate, introrse, longitudinally dehiscent; connective elliptical with lateral sporangia, inflexed in bud
• Disc absent
• Ovary superior, 2(3)-locular, bilaterally compressed; style stout, shorter than ovary, basal part persistent; stigma capitate, covered by minute papillae; ovules ± 15-20 per locule, anatropous, pleurotropous, superposed in a single vertical series; placentation axile
• Fruit a dorsiventrally compressed (rarely trigonous) capsule, loculicidal at apex, reddish brown
• Seeds ± 15-20 per locule, depressed-ovoid, narrowly winged (expanded raphe); testa thin and papery, rather smooth, brownish, without endosperm; embryo ± flattened, cotyledons folded inside

Nomenclature:

• Rhynchocalycaceae
  • Hiroshi & Raven: 836 (1984)
  • Johnson & Briggs: 700 (1984)
  • Dahlgren & Van Wyk: 45 (1988)

Distribution & Notes:

• Southern Africa: Rhynchocalycaceae is a monotypic family proposed by Johnson & Briggs (1984). Rhynchocalyx lawsonioides Oliv. is a rare, but locally quite common, evergreen tree endemic to the sandstone (Natal Group; previously known as Table Mountain Sandstone) region of S KwaZulu-Natal and Pondoland (Eastern Cape). First collected in 1884, it was only rediscovered in 1966 (Strey & Leistner 1968). It grows mainly on forest margins, often near water courses

References:

• DAHLGREN, R. & VAN WYK, A.E. 1988. Structures and relationships of families endemic to or centered in southern Africa. Monographs in Systematic Botany from the Missouri Botanical Garden 25
• HIROSHI, T & RAVEN, P.H. 1984. The embryology and relationships of Rhynchocalyx Oliv. (Rhynchocalycaceae). Annals of the Missouri Botanical Garden 71
• JOHNSON, L.A.S. & BRIGGS, B.G. 1984. MYRTALES and Myrtaceae - a phylogenetic analysis. Annals Missouri Botanical Garden 71

Resources:

• Rhynchocalycaceae genus: Rhynchocalyx