Humiriaceae

Authority

Cuatrecasas, José. 1961. A taxonomic revision of the Humiriaceae. Contr. U. S. Natl. Herb. 35: 25-214. pl. 1-24.

Family

Humiriaceae

Scientific Name

Humiriaceae

Description

Description - Flowers hermaphroditic, complete, actinomorphic. Sepals 5, persistent, thick and carnose at base, thinner toward margin, suborbicular or triangular, more or less connate in tube or cupule, glabrous, pubescent or tomentous outside, sometimes with marginal or dorsal glands; estivation quincuncial or imbricated; all same size or 2 outer ones smaller. Petals 5, deciduous or sometimes persistent, free, thick or membranaceous, usually 3-5-nervate, oblong, linear or oblong-lanceolate, acute to obtuse, rarely with gland at top, margin smooth, sometimes with tooth at 1 side near apex, above glabrous, below glabrous or pilose, white, greenish white, or yellowish white, rarely red; estivation contorted, cochlear or quincuncial, indistinctly dextrorse or sinistrorse. Stamens monadelphous, numerous (indefinite) and pluriseriate or in definite number, 30-10 and 1-2 seriate. Filaments filiform (when numerous), slender and flexuose, or thick, complanate, linear, acute at apex, straight and glabrous or papillose; at base connate in more or less long tube, alternating in different lengths, sometimes the 5 alternating with the petals are trifurcate at apex and triantheriferous. Anthers dorsifixed or subbasifixed; thecae 2, bilocular, laterally attached, ellipsoid-oblong and each cell dehiscing by longitudinal slit, or 4, unilocular, rounded or ellipsoid disjunct thecae (2 lateral and 2 basal), dehiscing by detachment, or 2 unilocular, disjunct, basal, dehiscing by detachment; connective thick, fleshy, ovoid or lanceolate, obtuse at apex or most commonly produced in apiculum or linguiform appendix. Sometimes some filaments lack anther; occasionally smaller, sterile filaments (staminodia) present. Pollen grains usually 3-colporate, also 4-colporate, suboblate, oblate-spheroidal, prolate-spheroidal (27X32, 31X35, 33X3µ), exine not verrucose, tenuisexinous (Erdtman). Intrastaminal free disk girding ovary, membranaceous or subcoriaceous, tubular or cupular, dentate, lobate, laciniate or composed of 10-20 free scales. Gynoecium syncarpous, carpels 5 (rarely 4, 6, or 7), opposite sepals or alternate. Ovary ovoid or ellipsoid, sessile, 5 (4, 6, 8) septate with axile placentation, cells uniovulate or biovulate. Style single, entire, columnar, erect, as long as stamens or shorter, rarely longer. Stigma narrowly or broadly capitate, 5-lobate or 5-radiate. Ovules anatropous, epitropous with 2 integuments, pending at inner angle of ovary cells, micropyle pointing upward, raphe ventral; when 2 ovules present in each cell, superposite and lower one hanging from longer funiculus. Fruit drupaceous from size of pea to that of mango exocarp hard-fleshy varying from pulpy to fibrous, subcoriaceous texture. Endocarp (putamen) woody, usually very hard, compact or with many resin-filled, round cavities, rarely spongious-woody, 5 (4, 6, 7) septate, commonly with only 1-2, rarely 3, 4, or 5 seeds developed; surface smooth, bullate, rugose, or tuberculate, slightly striate or strongly costate; with germinal dehiscence, provided with as many longitudinal opercula or valves as carpels, which may open or be pushed away by emerging embryo at germination of seed inside fruit. Often subapical foramina are present. Seeds oblong with double testa, exterior often adherent to putamen, inner membranaceous, thin; embryo straight or slightly curved, cotyledons oblong or ovate, often subcordate at base, radicle half as long, endosperm fleshy and oily. Woody, evergreen plants from small shrubs to large trees; wood reddish, hard, often with balsamic juice. Leaves alternate, simple, often distichous, coriaceous or subcoriaceous, penninerved, entire, crenulate or slightly serrate, petiolate or rarely sessile, sometimes decurrent along branches, often punctate-glandulose near margin on underside, marginal teeth when young often aculeate, later calloustipped. Stipules very small, geminate, deciduous or lacking. Inflorescences axillary, pseudoterminal or rarely terminal, paniculate, often corymbiform, of dichasial type and trichotomous, but through reduction often with dichotomous or alternate (cincinnate) branching; branchlets often with incrassate ends, articulate. Pedicels short, articulate. Bracts and bracteoles persistent or deciduous, small, amplectant. Wood, according to Record and Hess: "Heartwood grayish brown to reddish or purplish brown; distinct but not sharply demarcated, from the sapwood. Luster usually low. Odorless and tasteless when dry. Hard and heavy to decidedly so; sp. gr. (air-dry) 0.80 to 1.10; weight 50 to 69 lbs. per cu. ft.; texture medium to coarse; grain mostly irregular; not easy to work; is tough and strong; finishes smoothly; durability doubtful." For further technical characteristics, see Record and Hess, p. 191-192, 1943; see also figure 3.

Uses - Economic uses: The bark and wood of some species and varieties of Humiria produce the "umiri" or "umiry-balsam," with properties similar to those attributed to the Copaiva and Peruvian balsam. Little is known about its preparation, trade, and chemical composition (Wiesner, 1927, p. 1040; Wehmer, 1929, p. 597; Urban, 1887, p. 453). The exocarp of the fruits of Humiriaceae is more or less fleshy and in some species edible, as in many Humiria varieties and in some of Sacoglottis and Vantanea. The exocarp and seeds contain a fatty oil that in some places of the Amazon is used in the domestic economy. The oil of "uchi" has organoleptic properties similar to those of olive oil (Pereira Pinto, 195G). The seeds of Sacoglottis gabonensis contain 54 percent fatty oil (Wehmer, 1929, p. 597; Wiesner, 1927, p. 743). The wood of the Humiriaceae is hard and used locally in construction work. Metcalf and Chalk (1950, pp. 277-279) wrote about its economic uses thus: "The timbers of this family are dense; they are of little importance though some species of Humiria are used in tropical America for heavy construction, wheels, etc."

Discussion

According to Croizat (1952, p. 388), the Humiriaceae belong to a Genorheithrum of Gondwanic origin and reached the Americas from the east. Andean fossils prove that abundant earlier populations in that region were deeply disturbed by the uplifting of the Andes, and that the Humiriaceae existed in the New World long before the Tertiary.