Coccoloba sect. Paniculatae
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publication ID |
https://doi.org/10.11646/phytotaxa.704.2.2 |
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persistent identifier |
https://treatment.plazi.org/id/03BA0B6B-FFBE-4D4A-2EE0-F09EFA9AF927 |
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treatment provided by |
Felipe |
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scientific name |
Coccoloba sect. Paniculatae |
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Morphology of Coccoloba sect. Paniculatae
Habit and leaf: — The species of Coccoloba sect. Paniculatae are trees or shrubs, 2‒30 m; branches with nodes and internodes, striate, glabrous, or with indumentum, lenticellate and some with glandular points. The ochrea are quickly deciduous, membranous or chartaceous, glabrous or with indumentum, whether pubescent, strigose, puberulent, hirsute or woolly; the petiole is glabrous or puberulent, strigose or hirsute; in all species the petiole originates from the basal part of the ocrea. The leaves are ovate, broadly obovate, elliptic, elliptic-oblong or lanceolate, glabrous or abaxially hirsute, strigose, puberulent or pubescent.
Inflorescences:—Inflorescences in Coccoloba sect. Paniculatae species may be racemiform or spiciform, grouped in a panicle. The panicles may present two types of growth: monopodial, that is, with a well-developed main axis, generally greater than 8 cm long ( Fig. 1A View FIGURE 1 ); this type of panicle is present only in South American species such as C. mollis , C. efigeniana J.J.Ortiz-Diaz & J.J.Ancona and C. gigantifolia E.Melo, C.A.Cid Ferreira & R.Gribel. On the other hand, the remaining species of the section present panicles with sympodial growth, which have a reduced main axis, less than 1–3 cm long, rarely reaching 5 cm ( Fig. 1C View FIGURE 1 ). In general, Coccoloba species considered to have spiciform inflorescences are characterized by the complete absence of the pedicel or with reduced pedicels to less than 1 mm long ( Fig. 1B View FIGURE 1 ); while the species considered to be racemiform have the pedicel greater than 1.2 mm long ( Fig. 1D View FIGURE 1 ).
Flowers: — The flowers in Coccoloba sect. Paniculatae are similar to the flowers of the rest of Coccoloba species, the floral characters are not taxonomically informative for delimiting the species. They are usually very small flowers 2–3 mm long, creamy-yellow or greenish, with aestivation quincuncial, the 5 tepals are arranged in two alternate whorls, 3 outer tepals and 2 inner ones, outer tepals are coriaceous, some species have indumentum (e.g. C. efigeniana , C. mollis , C. hirsuta Standl. ), inner tepals are papyraceous and glabrous ( Fig. 1 E and F View FIGURE 1 ), the stamens varies from 8 to10, the ovary is ovoid an the style is capitate. The flowers are hermaphrodite, but functionally unisexual, except in C. gigantifolia which is polygamous-dioecious. Functionally male flowers have stamens twice as large as the gynoecium and are arranged in a fascicle of 2–4 (+) flowers on the rachis of the inflorescence. Functionally female flowers are solitary along the rachis and have the gynoecium twice as large as the stamens. Bracteoles and ochreolas are two characters associated with flowers, the ochreolas in this section are usually small, 1–2.5 mm long, chartaceous, sometimes membranous, glabrous or puberulent-pulverulent and are found surrounding the pedicels of the flowers; while the bracteoles are located under the flowers, surrounding these and the ochreolas, they are small 1–2 mm long, cymbiform, puberulent, hirsute or scabrid.
Fruits:—In Polygonaceae the fruits have been described as achenes surrounded by the membranous and accrescent tepals. However, in this work we adopt the term “acrosarcum”, to describe the fruit in a broad sense to include the achenes surrounded by the succulent hypanthium, a condition present in the Coccoloba sect. Paniculatae . This can vary in shape, from globose, subglobose, ovoid and only C. efigeniana presents a triangular or obpyramidal acrosarcum, these can be glabrous or pilose ( Fig. 1 G and I View FIGURE 1 ). And the achene or pericarp was described by removing the hypanthium, the achene also varies in shape and at the apex ( Fig. 1H and J View FIGURE 1 ). There are ovoid, globose or obpyramidal achenes, with conical, cuspidate or campanulate apices.
Distribution and Diversity:— Coccoloba sect. Paniculatae has 17 species that extend from Mexico to South America ( Fig. 2 View FIGURE 2 ). Only two species are distributed beyond this range: Coccoloba proctorii R.A.Howard and C. plumieri Griseb. that are found in Jamaica and both are endemic. Mexico is the country with the highest number of species and endemism, with eight species of which six are endemic. Brazil has three species, one of which is endemic. Fig. 2 View FIGURE 2 shows the diversity and number of endemic species for each country.
The review of herbaria and occurrence records of Coccoloba sect. Paniculatae species downloaded from GBIF and The Naturalist platforms allowed us to analyze points with higher occurrence. In Fig. 3A View FIGURE 3 we can see that there are five geographic areas with the highest concentration of Coccoloba sect. Paniculatae specimens. In southern Brazil, in the states of Sao Paulo, Mato Grasso and Paraná, the number of specimens varies from 62 to more than 217. The Caatinga is another geographic region of Brazil with high records of specimens, with 31 to 155. On the border between Bolivia and Peru, there is another area with high values of collected specimens, records vary from 31 to 124 specimens. Finally, in Central America, records in this region vary from 31 to 93 specimens. These specimen concentration data are in contrast with the species richness data ( Fig. 3B View FIGURE 3 ). Even though the largest number of specimen collections are concentrated in southern South America, all of these collections correspond to a single species ( C. mollis ). In the northern region of South America, however, there are few specimen records (≤ 31) but there are squares with two species ( Fig. 3B View FIGURE 3 ). In contrast, in Central America, the records are less than 100 specimens, but we can find cells with two or three species. On the contrary, in Mexico, even though diversity and endemism are high, the number of records is very low, which indicates that the sampling effort is low compared to countries in Central and South America.
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