Theobroma obovatum Klotzsch ex Bernoulli
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Authority
Cuatrecasas, José. 1964. Cacao and its allies, a taxonomic revision of the genus Theobroma. Contr. U. S. Natl. Herb. 35: 379-614. pl. 1-12.
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Family
Malvaceae
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Scientific Name
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Type
Type.—Maynas, Peru, Poeppig.
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Description
Description - Rather small tree up to 15 m. high; growth pseudoapical; trunk 10-25 cm. in diameter; primary branches ternate, the inferior horizontal, the upper ascending; terminal branchlets slender, when young ochraceo-ferruginous, densely lanate-tomentose, the intricate, long, stellate hairs more or less floccose, deciduous, when older glabrate, pale brown or pale gray, the rhitidome somewhat scaly; stipules narrow-linear, subulate, acute, tomentose, 3-5 mm. long, 0.5-1 mm. wide, soon deciduous. Leaves chartaceous, flexible, variable in size; petiole mediocre, subterete, transversely rimose, densely and thickly lanate-tomentose, ferruginous, when old the indument appressed, grayish, 4-15 mm. long; blades obovate-elliptic or obovate-oblong, more or less narrowed to the very asymmetrical and rounded base, more abruptly attenuate and cuspidate at apex, entire or slightly sinuate at margin, 7 x 3 to 38 x 13 cm., including the 0.5-3 cm. long acumen, varying very much in size on the same branch, when very young stellate-pilose above, then glabrous, pale olivaceous or pale brownish, shining, the main nerves depressed, filiform, the others obsolete, pale ochraceous or pale cinereous beneath, glaucescent, the costa very prominent, the 5-7 secondary nerves on each side prominent, curved-ascending, near the margin arched anastomosing, the lower pair usually forming an acute angle, ascending and more distally separated from the others, the transverse tertiary nerves thin but prominent, the minor veins forming a prominulous conspicuous reticulum, the costa and the principal lateral nerves covered when young, mainly towards the base, by a floccose deciduous indument of ochraceous, entangled, stellate hairs, in time becoming glabrous, shining, marked with minute callose, reddish, sparse dots, the tertiary nerves also glabrous, the minor veins, reticulum, and areoles covered by minute, white, stellate hairs forming an appressed, whitish tomentum. Inflorescences very small, axillary or in exfoliated, thin branchlets, the axis and branchlets of the cymes very reduced, ochraceous-ferruginous, lanuginose-tomentose; peduncles 2-7 mm. long, 3-bracteolate at apex ; pedicels 3-8 mm. long, somewhat thicker; bracteoles linear, 1.5-2 mm. long; buds globose, also ochraceous-lanuginose and woolly-tomentose. Sepals thick, ovate, subacute, slightly involute-marginate, about 6-7 mm. long, 3-4 mm. broad, united 1 mm. at base, rosy or reddish inside, subglabrous, glandular at base, 3-5 nerved, the margin minutely whitish tomentose, rather woolly outside, stellate-tomentose, spreading in anthesis; petal-hoods yellowish or reddish obovate, rounded cucullate and slightly retuse at apex, with 7 prominent nerves and copious, spreading, minute hairs inside, subglabrous with few, slender, flexuous hairs outside, 3-3.5 mm. long, 2.5 mm. broad; petallamina deep red, rather thick, suborbicular, often retuse at apex, abruptly contracted into a pedicel at base, pilose at margin, and with very sparse, flexuous, slender hairs on the inner side, 3.5 mm. long, 4 mm. broad; pedicel red, 0.6 mm. wide with sparse, slender hairs, 2.5 mm. long. Androecium tube about 1.5 m. high, glabrous; staminodes laminar, thick-membranaceous, deep red, oblong-elliptic, rounded and often emarginate at apex, attenuate near the base, with a conspicuous medial nerve and thin, flexuous, subspreading hairs distributed throughout, especially on the margins, 5-6 mm. long, 2.5-3 mm. broad; filaments thick, glabrous, 1.5 mm. long, shortly 3-furcate, 3-antheriferous; anther lobes ellipsoid, 0.4-0.5 mm. long; ovary ovoid, 1.5 mm. long, densely tomentose-hirsute; styles glabrous, 5 mm. long, united only at base. Fruit obovoid-ellipsoid, rounded at apex, contracted at base, greenish, when ripe brown yellowish, 5-7 cm. long, 3-4 cm. broad, the pericarp thin-coriaceous densely covered with acute, hard warts and sparse stellate hairs, when dry about 1.5 mm. thick; seeds 16 mm. long, 9 mm. broad; germination hypogeous.
Common Names - Cabega de urubti is the most common and widespread. Also, the following have been locally recorded: copu-ai, cupu-curúa, cupurana, cacao de macao, urubú-acain, cabeça de Umbú. Win-cheék (Puinave), Inírida-Guaviare; ma-oo-hee-rée (Kabuyarí) (Río Cananarí) (Angl. Col. Cocoa Exped., Baker 1952).
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Discussion
Theobroma obovatum is a rather small tree with a crowded, leafy crown, easy to recognize by its small, ellipsoid-obovoid fruits constricted at the neck, with thin, fragile, granulate or verrucose pericarp, usually green but becoming brownish yellow when ripe. Also characteristic are its light, papery, asymmetrical, oblong-obovate leaves with a close, white or cinereous monotrichous tomentum beneath; when very young the upper side, the principal nerves as well as the petioles, stipules, and twigs, are covered with an ochraceous brown or orange, easily removed down, composed of long, deciduous, stellate hairs. The fruit when ripe separates from the pedicel and falls. Schumann did not know the species, for it is lacking in his herbarium; he included the name T. obovatum as a synonym of T. subincanum in his treatment in the Flora Brasiliensis (p. 77). Huber knew the species well, although he called it T. sylvestre, confusing and misinterpreting Aublets figure of Cacao sylvestris. Ducke also knew T. obovatum and its distribution very well, but he thought that T. sylvestre Mart, was a synonym.