Monographs Details:
Authority:

Berg, Cornelius C. 1972. Olmedieae, Brosimeae (Moraceae). Fl. Neotrop. Monogr. 7: 1-229. (Published by NYBG Press)
Family:

Moraceae
Scientific Name:

Helicostylis
Synonyms:

Greeneina Kuntze, Helicostylis tomentosa (Poepp. & Endl.) Rusby
Description:

Description - Dioecious or monoecious trees. Leaves chartaceous to coriaceous, mostly brownish when dry, usually distinctly hairy, dull above; margin entire to denticulate towards the apex; pluricellular hairs globose- or oblongoid-capitate; stipules small, not fully amplexicaul, free, caducous. Staminate inflorescences discoid, pedunculate; receptacle revolute at least in the juvenile inflorescences; flowers mostly free; perianth 4-lobed to 4-parted; stamens (2-) 4, the stamens of the two whorls usually more or less different, filaments straight in the bud, connectives narrow or broad. Pistillate inflorescences solitary or in pairs, sessile to pedunculate, one-flowered or several-to many-flowered; perianth 4-lobed to 4-parted or with free tepals, the inner tepals cohering on the inner surfaces by entangled thin hairs; ovary almost free, stigmas vittiform or filiform, straight or twisted. Fruiting perianth yellow, fruit free or somewhat adnate to the perianth.

Discussion:

History.

The genus was described by Trécul (1847) who recognized one species, H. poeppigiana ( = Olmedia poeppigiana Martius = Olmedia tomentosa Poeppig & Endlicher). Miquel (1853) described a second species, H. affinis. Eleven new species were added to the genus in the 20th century. Three species described by Pittier (1918) proved to belong to Brosimum. The remaining species were correctly assigned to Helicostylis, in spite of the vague delimitation of the genus.

Bentham (1880) regarded Maquira as doubtfully congeneric with Helicostylis. Kuntze (1891) renamed the genus as he considered Helicostylis to be an orthographic variant of Helicostylum (-ium) Corda (1842), a genus of Fungi. This is not sanctioned by the present Code.

Seven species are distinguished in the present revision.

Staminate inflorescences.

Complemental staminate inflorescences are frequently met with. They are common in H. pedunculata but lacking in H. tovarensis. The number of primary staminate inflorescences in the axils of the leaves is as a rule great and the short shoots are well-developed; they are solitary or paired in H. tovarensis. The two whorls of tepals as well as the corresponding stamens are more or less different. The stamens opposite the inner tepals often mature earlier than those opposite the outer tepals, the filaments elongate earlier and become longer, and the anthers are often broader and shorter. In H. tovarensis the situation is the reverse. However, distinctly different and uniform stamens may occur in the same species. In some species, like H. elegans and H. heterotricha, the stamens are hardly or nor difform.

Pistillate inflorescences.

The inflorescences of H. tovarensis are uniflorous and often paired in the axils of the leaves. All other species have several- to many-flowered inflorescences which are solitary or accompanied by one or more staminate inflorescences. The inflorescences are always many-flowered in H. pedunculata; they bear about five flowers in most specimens of the other species. In most species the two whorls of tepals are distinctly different in shape. The inner tepals are plane and their free margins are covered by the margins of the more or less conduplicate outer ones. This is less distinct in H. pedunculata and H. turbinata. Entangled, thin, curled hairs inserted in the upper part of the inner surface make the inner tepals cohere. The shape of the hairy part depends on the shape of the tepal and the position of the style. In in-fructescences such thin hairs may also be found on more parts of the inner tepals (mainly marginal) and even on the fruits. Especially in H. elegans, H. scabra, and H. tomentosa, the ovaries are laterally adnate to the base of the flower, making them supine in position.

Taxonomic notes.

The genus is well-characterized by the more or less distinct two-whorled arrangement of the floral parts and the way in which the inner tepals of the pistillate flowers cohere.

H. tovarensis differs markedly from the other six species. It was described as Olmedia tovarensis and shows a great deal of superficial resemblance to Olmedia aspera. On account of the structure of the flowers it is placed in Helicostylis (cf Miquel 1853) where it forms a section all by itself. The remaining species are (rather) closely related and are partly difficult to separate. This pertains especially to H. tomentosa, H. scabra, and H. elegans. They cannot be easily keyed out, but they differ rather much in their overall appearance and can be regarded as distinct species without doubt. However, for correct determination comparison with other herbarium specimens will often prove necessary.