Cordia
Description
Medium sized trees, shrubs or woody climbers.
Leaves alternate, rarely subopposite, stalked, unsually entire, sometimes indistinctly crenate.
Inflorescences terminal or axillary, panicled to corymbose, sometimes very few-flowered, subglobose, with scorpioid branches.
Flowers with a short, distinct pedicel or subsessile, (4-)5-16-merous, bisexual, sometimes functionally monosexual and dioecious. In male flowers the ovary reduced and style absent, in female flowers the anthers sterile.
Stamens of same number as corolla-lobes, included or exserted; filaments glabrous or pubescent at base; anthers oblong, ovate to subquadrate.
Ovary 4-locular with one erect ovule in each locule; style twice forked, terminal; stigma elongate on each branch or subcapitate. Fruit drupaceous, as a rule partially included in the persistent, cupuliform calyx.
Distribution
America present, Asia-Tropical
A pantropical genus of about 250-300 species. In Malesia represented by 8 indigenous species and 4 species introduced from tropical America
Morphology
Certain anatomical features seem to be of taxonomic value. Crystals present in the secondary xylem can either be described as crystal sand, or there are prismatic crystals either additionally or as the only type, or a special columnar type of crystals is developed. As far as known, only C. subcordata is characterized by crystal druses.
In the leaves, cystoliths either are confined to epidermal cells or also found in the basal part of trichomes.
Hairs, especially of the axis, are simply strigillose or with two horizontal, apical branches, or they are stellate (especially in subg. Gerascanthus), sometimes, especially in American groups, bearing glandular heads.
Chromosome numbers are derived from the basic numbers 7 (in subg. Myxa), 8 (in subg. Cordia and in some species of subg. Gerascanthus), 9 (in subg. Varronia) and 15 (in some species of subg. Gerascanthus). Polyploidy is not infrequent. The highest diploid number counted is 'more than 80' in C. rothii (subg. Myxa).
In the leaves, cystoliths either are confined to epidermal cells or also found in the basal part of trichomes.
Hairs, especially of the axis, are simply strigillose or with two horizontal, apical branches, or they are stellate (especially in subg. Gerascanthus), sometimes, especially in American groups, bearing glandular heads.
Chromosome numbers are derived from the basic numbers 7 (in subg. Myxa), 8 (in subg. Cordia and in some species of subg. Gerascanthus), 9 (in subg. Varronia) and 15 (in some species of subg. Gerascanthus). Polyploidy is not infrequent. The highest diploid number counted is 'more than 80' in C. rothii (subg. Myxa).
Taxonomy
The delimitation of the genus Cordia has varied a great deal in the past from author to author. It has been split into as many as ten different genera (Friesen 1933), while I.M. Johnston (1930 to 1951) accepted it in a broad sense dividing it into 5 sections. The most recent treatment by Borhidi et al. (1988) takes an intermediate path acknowledging three genera: Cordia, Varronia and Gerascanthus. Cordia is not subdivided any further, in the exclusively American genus Varronia three sections are recognized, in Gerascanthus two subgenera. Unfortunately, the very thorough morphological, anatomical and cytological paper of Heubl et al. (1990) was not yet known to them. Taking into account obvious correlations in chromosome numbers, pollen morphology and crystal pattern in the wood among each other and with other characters, it seems better to include Gerascanthus in Cordia and ascribe generic rank to the much more different Varronia, as has been proposed already by De Candolle in 1845. In the Malesian area, only true Cordia is found according to that proposal. It is further divided into three subgenera in the following way.