Actinodaphne

General description: 

Evergreen trees or shrubs.  Terminal buds usually perulate, with conspicuous scales, leaving a ring of scars immediately above the pseudowhorl of leaves (or leaf scars).

Leaves alternate but usually distinctly aggregate to subverticillate, usually penninerved, rarely subtriplinerved.

Inflorescences involucrate, most frequently several (sub)sessile involucrate umbels aggregated in the axil of a leaf or on a leafless part of the twig, but also involucrate umbels arranged in a raceme or rarely in a panicle, or a whole raceme enclosed in an involucre.

Flowers usually trimerous, unisexual, dioecious.  Tepals usually 6, (sub)equal, spreading to reflexed at anthesis.  Male flowers: Stamens usually 9 (rarely more), in 3 whorls, stamens of the third whorl with a pair of glands at the base of the filaments.  Anthers 4-locular, the pollen sacs (more or less) in two pairs, one above the other, all introrse or lower pollen sacs latrorse.  No staminodes in addition to the fertile stamens.  Pistillode small or absent.  Receptacle small and shallow.  Female flowers: Staminodes usually 9, the inner 3 with paired glands.  Ovary superior, with enlarged stigma.  Receptacle small and shallow to deeply cup-shaped.

Fruit globose to ellipsoid, seated on a flat to cup-shaped cupule.  Tepals mostly deciduous, occasionally partly persistent on the margin of the cupule.

Tropical to warm-temperate Asia, India to Japan and Indonesia.  More than 160 published binomials, number of species difficult to estimate, perhaps ca. 80-100.  Badly in need of revision.

There is no easy way to recognize Actinodaphne.  However, if you see a tree (in tropical or subtropical Asia) that has simple, entire, penninerved leaves are clustered at the tips of the branches, or at regular intervals along the younger branches, then Actinodaphne should be among the names considered.  For a student living within the native range of Actinodaphne, a master thesis on its inflorescence construction and development might be a worthwhile subject.  This is one of the aspects that are not yet understood about the genus.

Actinodaphne is a member of the Litsea complex in the Laureae, and there are strong indications that it is not monophyletic (Li et al. 2004, 2006).

Further information:

Julia, S. 2005. A synopsis of the genus Actinodaphne Nees (Lauraceae) in Sabah and Sarawak, Malaysia. Gardens’ Bulletin Singapore 57: 69–100.

Kochummen, K.M. 1989. Lauraceae. In: Tree Flora of Malaya. F.P.S. Ng (Ed.), Vol. 4, pp. 98–178. Longman, Kuala Lumpur.

Li, J., Christophel, D.C, Conran, J.G. & Li, H.W. 2004. Phylogenetic relationships within the ‘core’ Laureae (Litsea complex, Lauraceae) inferred from sequences of the chloroplast gene matK and nuclear ribosomal DNA ITS regions. Plant Systematics and Evolution 26: 19–36.

Li, Z.M., Li, J. & Li, X.W. 2006. Polyphyly of the genus Actinodaphne (Lauraceae) inferred from the analyses of nrDNA ITS and ETS sequences. Acta Phytotaxonomica Sinica 44: 272–285.

Tanaros, M., Vajrodaya, S. & Chayamarit, K. 2010. Taxonomic study of the genus Actinodaphne Nees (Lauraceae) in Thailand. Thai Journal of Botany 2: 7–23.

Huang, P. & van der Werff, H.  2008.  Actinodaphne in Flora of China in efloras.org: http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=100442

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith