Neotropical Theophrastaceae

Bertil Ståhl

Gotland University, Visby, Sweden. 
 

Description

Shrubs or small trees, usually evergreen, hermaphrodite or in Clavija Ruiz & Pav. usually dioecious or subdioecious. Leaves alternate, often pseudo-verticillate, exstipulate, petiolate, simple, glandular-punctate, mostly with bundles or layers of subepidermal, extraxylary sclerenchyma. Inflorescences terminal or lateral, basically racemose but through reductions sometimes appearing as few-flowered umbels, rarely single-flowered, each flower subtended by a small bract. Flowers regular or slightly asymmetric because of unequal size of the corolla lobes, 5- or 4-merous, bisexual or in Clavija often unisexual, the aestivation imbricate. Calyx persistent, lobes free to base, glandular punctuate, margins membranaceous. Corolla sympetalous, usually firm and waxy in texture, lobes usually somewhat unequal in size. Staminodal structures present, fused to the corolla tube, alternating with the lobes. Stamens homomerous, antepetalous; filaments flattened, ± fused at base and to the lower part of the corolla tube, free to base or in Clavija often united into a tube; anthers basifixed, extrorsely dehiscent with longitudinal slits, the upper and lower parts of thecae filled with calcium oxalate crystals. Gynoecium superior; ovary ovoid to subglobose, undivided, unilocular; style short to somewhat longer than ovary; stigma entire or vaguely lobed, truncate or capitate; ovules few to numerous, spirally inserted on a basal column. Fruit a berry with a dry and sometimes woody pericarp, indehiscent, subglobose, oblong, or ovoid, yellow or orange. Seeds dark brown to brownish-yellow, partly or entirely embedded in placental tissue, endosperm abundant; embryo straight or slightly curved, cotyledons linear or foliaceous.

Notes on delimitation

  • Not including Samolaceae, a sister group occasionally merged with the Theophrastaceae.

Distribution in the Neotropics

  • NW Mexico and S Florida to S Brazil and Paraguay.

Distinguishing characters (always present)

  • Schizogenous secretory cavities lacking.
  • Free central placenta.
  • Stamens epipetalous; anthers extrorsely dehiscent partly filled with accumulations of calcium oxalate crystals.
  • Corolla tube with a ring of staminodal structures, alternating with the petals.
  • Fleshy fruits with a dry exocarp and few to many large seeds.

Other important characters

  • Leaves with subepidermal layers or bundles of extraxylary sclerenchyma.

Key differences from similar families

Number of genera

  • Bonellia Bertero ex Colla
  • Clavija  Ruiz & Pav.
  • Deherainia Decne.
  • Jacquinia L.
  • Neomezia Votsch
  • Theophrasta L.
  • Votschia Ståhl

Notable genera and distinguishing features

  • Clavija, Neomezia, Theophrasta: monocaulous shrubs and treelets.
  • Bonellia and Jacquinia: often spine -tipped leaves.
  • Deherainia: large green flowers with foetid scent.

Status

  • Endemic.

Important literature

Ståhl, B. Theophrastaceae. Flora Neotropica Monographs (in press).

How to cite

Ståhl, B. (2009). Neotropical Theophrastaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/neotropikey/families/Theophrastaceae.htm.