Neotropical Achariaceae

Mac H. Alford

University of Southern Mississippi, USA.

Description

Habit: trees or shrubs. Leaves alternate, simple, sometimes crowded toward apex (Carpotroche), spirally or sub -distichously arranged (Chiangiodendron), pinnately veined (with numerous parallel secondaries like Clusia in Kuhlmanniodendron), margins entire to serrate or dentate, glabrous or pubescent with simple trichomes or (rarely) scales, petioles short to long, often thickened at the base and apex, stipulate or exstipulate (Chiangiodendron). Sexuality bisexual, andromonoecious, monoecious, dioecious, or androdioecious. Flowers solitary or inflorescences of fascicles, racemes, or panicles; axillary, sub-terminal, or cauliflorous. Hypanthium lacking. Sepals (2-) 3 (or 5 in Chiangiodendron), sometimes caducous. Petals (5 in Chiangiodendron) otherwise 6-12, sometimes longer than the sepals, sometimes caducous, rarely with an adaxial fleshy scale / appendage (Chiangiodendron). Disk absent. Stamens 5 to numerous (ca. 50), filaments glabrous or pubescent, anthers linear-elongate or sagittate (Chiangiodendron), longitudinally dehiscent. Gynoecium of one pistil, ovary superior, unilocular, placentation parietal, style(s) 1-8(-10), stigmas obscure, capitellate, or lacerate. Fruits baccate or capsular, sometimes tardily dehiscent, thin or thick / woody, smooth or ornamented with warts, spines, bristles, or vertical wings. Seeds 1 to numerous, arillate.

Notes on delimitation

Achariaceae were traditionally a small South African family of flowering plants. Recent phylogenetic analyses using DNA sequence data affirm that Achariaceae s.s. are nested within the cyanogenic taxa of the former Flacourtiaceae (tribes Pangieae, Lindackerieae [Oncobeae, in part], and Erythrospermeae). These taxa have been united in one family, which takes the name with priority, Achariaceae (Eurosids I: Malpighiales). Occasionally, the taxa of the former Flacourtiaceae have been segregated from Achariaceae into the family Kiggelariaceae, but more recent studies do not support this exclusion. The family is not very diverse in the Neotropics; more genera and species occur in tropical Africa and Asia.

Distribution in the Neotropics

  • Carpotroche Endl. - Guatemala to Brazil.
  • Chiangiodendron Wendt - Mexico.
  • Kuhlmanniodendron Fiaschi & Groppo - Brazil.
  • Lindackeria C.Presl - Mexico to Brazil and Bolivia.
  • Mayna Aubl. - Honduras to Brazil and Bolivia.

Distinguishing characters (always present)

Other important characters

  • Leaf bases usually acute to long-cuneate.
  • Petiole thickened at base and apex, often flexed.
  • Inflorescences axillary (or sub-terminal).
  • Petals usually longer and more numerous than the sepals (except Chiangiodendron).
  • Anthers linear-elongate (sagittate in Chiangiodendron).
  • Variable and sometimes uncommon sexual conditions (bisexual, andromonoecious, monoecious, dioecious, or androdioecious).
  • Fruits often highly ornamented (tubercles, warts, or thick spines in Lindackeria; thin bristles in Mayna; wings or lacerate wings in Carpotroche).
  • Sometimes cauliflorous (Carpotroche).
  • Cyanogenic.

Key differences from similar families

  • Achariaceae are a heterogeneous family, but most of the Neotropical taxa (except for Chiangiodendron) belong to tribe Lindackerieae, which are usually distinctive in having longer and more numerous petals than sepals, linear -elongate anthers, and ornamented fruits.
  • Most Achariaceae, including Chiangiodendron, also have flexed petioles with thickened bases and apices.

Number of genera

  • Carpotroche (11 spp.) – Endemic.  Fruits winged, sometimes wings lacerate.
  • Chiangiodendron (1 sp.) – Endemic.  Petals with adaxial bifid scale.
  • Kuhlmanniodendron (1 sp.) – Endemic.  Leaf venation like Clusia.
  • Lindackeria (6 spp.) – Native.  Fruits warty or with thick, sharp projections.
  • Mayna (5—6 spp.) – Endemic.  Fruits with slender bristles.

Useful tips for generic identification

Key to genera of Neotropical Achariaceae

1. Sepals 5; petals 5; stamens, if present, 5 ...Chiangiodendron
1. Sepals (2-)3; petals (4-)6-12; stamens, if present, 14 or more...2

2. Style 1; fruit surface with warts or coarse, fibrous spines ...Lindackeria
2. Styles (2-)3-8(-10); fruit surface smooth, with vertical ridges or wings, or covered with slender bristles...3

3. Leaf venation Clusia-like (dense, straight, parallel secondary and intersecondary veins which end in a marginal vein); scaly trichomes on leaves present; stamen filaments glabrous; fruit surface essentially smooth ...Kuhlmanniodendron
3. Leaf venation not Clusia-like (occasionally secondary veins are straight and parallel but are not dense and do not end in a marginal collecting vein); scaly trichomes absent; stamen filaments hairy; fruit surface with vertical ridges or wings or covered with slender bristles (rarely smooth)...4

4. Fruit berry-like, with a thin fruit wall, covered with slender bristles; styles (2-)3-4(-5) ...Mayna
4. Fruit capsular, with a thick fibrous fruit wall, with vertical ridges or wings; styles (4-)6-7(-8  ...Carpotroche

Notable genera and distinguishing features

See above

Status

See above

Important literature

Sleumer, H. O. 1980. Flacourtiaceae. Flora Neotropica No. 22. Bronx: New York Botanical Garden.

Alford, M. H. 2003. Claves para los géneros de Flacourtiaceae de Perú y del Nuevo Mundo. Arnaldoa 10(2): 19-38.

Chase, M. W., S. Zmarzty, M. D. Lledó, K. J. Wurdack, S. M. Swensen, & M. F. Fay. 2002. When in doubt, put it in Flacourtiaceae: a molecular phylogenetic analysis based on plastid rbcL DNA sequences. Kew Bulletin 57: 141-181.

Fiaschi, P. & M. Groppo. 2008. Kuhlmanniodendron Fiaschi & Groppo, a new eastern Brazilian genus of Achariaceae sensu lato segregated from Carpotroche Endl. (formerly included in Flacourtiaceae). Botanical Journal of the Linnean Society 157: 103-109.

Wendt, T. 1988. Chiangiodendron (Flacourtiaceae: Pangieae), a new genus from southeastern Mexico representing a new tribe for the New World flora. Systematic Botany 13(3): 435-441.

How to cite

Alford, M.H. (2009). Neotropical Achariaceae. In: Milliken, W., Klitgĺrd, 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/Achariaceae.htm.