Dulacia

Authority

Sleumer, Hermann O. 1984. Olacaceae. Fl. Neotrop. Monogr. 38: 1-159. (Published by NYBG Press)

Family

Olacaceae

Scientific Name

Dulacia

Type

Type species. D. singularis Vellozo.

Synonyms

Liriosma, Hypocarpus

Description

Genus Description - Shrubs (occasionally scandent) or trees. Branches slender, flexuous, often yellowish in the dry state. Leaves alternate, entire, penninerved, short-petiolate. Flowers bisexual, heterostylous, scented, generally rather few per axillary simple or laxly composed (cymoid) raceme; rhachis straight to zig-zag; pedicels short; bracteoles subpersistent. Calyx small, cupular, edge obsoletely and obtusely 5-lobed or -undulate or truncate, narrowed towards the base and continuous with the pedicel, i.e. forming an hypanthium with the latter, much accrescent towards fructification and finally including the fruit almost entirely. Petals 6, slightly perigynous, valvate, connate more or less halfway, apex inflexed, caducous. Fertile stamens 3, each inserted at the fused bases of two petals; filaments flat, adnate to the basal part of the petals, usually hairy; anthers oblong, dorsifixed, longitudinally dehiscent. Staminodes 6, epipetalous, spathulate, usually hairy below, bifid and glabrous in the upper ½. Disk hypogynous, cup-shaped and adnate to the calyx, free only at the upper margin (on which the petals are inserted), hardly noticeable and not accrescent. Ovary semi-inferior, i.e. inserted halfway in the disk, 3-celled below, 1-celled above; placenta basal, from the top of which a single ategmic ovule is pendent into each cell; style subcylindric, rather slender, either short and ending at the base of the anthers, or elongate and exceeding the anthers somewhat; stigma subcapitate, slightly 3-lobed in the brachystylous, more distinctly so in the dolichostylous flowers. Fruit a pseudo-drupe, included by the enlarged thin-fleshy calyx except the free umbonate top of the ovary, drupe, and style-base; endocarp woody to crustaceous. Seed 1; testa thin; endosperm copious, fleshy, containing abundant fatty oil and fairly frequent to scarce (rarely no) starch grains; embryo small, in the apical part of the albumen; cotyledons ovate.

Discussion

Heterostyly in this genus, first mentioned by Engler (1872, sub Liriosma pallida), occurs regularly. Most species have both dolichostylous and brachystylous forms, formerly kept apart as separate species. From other species only the dolicho- or brachystylous form is as yet known. It is probable that the brachystylous form, with its less distinctly developed stigma, is generally functionally [male], and only the dolichostylous form is [male and female] Fruit-bearing occurs usually with the dolichostylous, rarely with the brachystylous form.

Distribution

Amazonian Colombia, Venezuela, the Guianas, Ecuador, Peru, Brazil, and Bolivia, also in E and SE Brazil (Bahia to Paraná); in forest, also dry or restinga forest, bushy savanna, usually on terra firme, rarely on seasonally inundated ground, at low alt.

Colombia South America| Venezuela South America| Guyana South America| French Guiana South America| Suriname South America| Ecuador South America| Peru South America| Brazil South America| Bolivia South America|