Prestonia mexicana A. DC.

Tanto en zonas calientes como húmedas.

Distribucion en Costa Rica: Ambas vertientes, elevación entre los 0--1800 m.
Distribucion General: México a Panamá.

Liana.

En el crecimiento de tallos jóvenes, los nectarios que se encuentran en las axilas de los peciolos producen una fina secreción, por lo que es muy común encontrar esta planta asociada a hormigas durante esta fase de desarrollo. Con el tiempo, al madurar los tallos, estas glándulas pierden su función y se convierten en meras estructuras accesorias.

Liana o bejuco semiherbáceo, los tallos densamente pubescentes o tomentosos, ferrugíneos. Hojas elípticas, ovadas u obovado - elípticas de (7) 9,5 - 27 cm por 6 - 13,5 cm, membranosas o subcoriáceas, puberulentas o levemente pubescentes en el haz, densamente tomentosas o híspidas en el envés, agudas o corto - acuminadas, redondeada o subcordada en la base, peciolo de 0,4 - 1,9 cm largo, glandular en las axilas Inflorescencia subumbelosa, rara vez racemosa, simple, axilar, con muchas flores (7 - 23), medianas, pedúnculo de 1 - 6 cm largo, tomentuloso, brácteas ovadas o lanceoladas, foliáceas de 0,7 - 2,2 cm largo, pedicelo de 0,4 - 2,4 cm largo, tomentuloso.Lóbulos del cáliz foliáceos, ovados - lanceolados u oblonlanceolados de 1,2 - 3,2 cm largo, estrigosos o adpreso - tomentulosos, agudos o acuminados, con una glándula en su interior; corola hipocrateriforme, amarillo - crema o blanca moteado con verde, ferrugíneo - villoso en el exterior, tubo de 2 - 3,2 cm largo, los apéndices epiestaminales remplazados por cresta callosas lineares, lóbulos oblicuamente obovados de 1,1 - 1,6 cm largo; estambres ubicados cerca de la garganta, anteras glabras, con la punta exherta de 6 - 7 cm largo. Folículos verde ferrugíneo, híspidos, gruesos de (7) 9 - 13 cm por 1,2 - 1,9 cm. Semillas de 1,1 - 1,8 cm largo, rugosas o papilladas.

Se informa de su uso como "barbasco" para la pesca en ríos, donde la planta recién cortada se introduce en el agua y se macera, sobretodo en sitios con poca corriente o "pozas".

Localidad del tipo: México, Oaxaca: San Bartolo.
Depositario del tipo: Holotipo, G-DC. (Foto: F,INB,MO,NY,US)
Recolector del tipo: Andrieux (251)

Prestonia amanuensis Woodson, Ann. Mo. Bot
Gard. 23: 359. 1936.
Suffruticose liana, ferruginous-pubescent throughout; leaves firmly membranaceous, broadly ovate, 6-9 cm. long, 4r-7 cm. broad, abruptly and shortly acuminate, broadly and obscurely cordate at the base, densely hispidulous above, densely tomentulose beneath, the petioles 2-3 mm. long, tomentulose; inflorescence densely subumbellate, simple, bearing 6-12 cream-colored flowers, the peduncle much shorter than the leaves, tomentose; pedicels 3-5 mm. long, tomentulose; bracts ovate-lanceolate, 3-7 mm. long; calyx-lobes ovate-lanceolate, acuminate, 11-17 mm. long, foliaceous, minutely appressed-hirtellous; corolla salverform, ferruginous-villous externally, the tube 20-22 mm. long, about 3 nun. in diameter at the base, the epistaminal appendages replaced by subquadrate protuberances, the lobes obliquely obovate, 8-9 mm. long; anthers glabrous, slightly exserted; nectaries concrescent, annular, essentially entire, about as long as the ovary; follicles unknown.
Type locaIvITy: Stann Creek Railway, British Honduras. Distribution: British Honduras.

Prestonia mexicana A. DC. in DC. Prodr. 8: 429. 1844
Haemadictyon mexicanum A. DC. in DC. Prodr. 8: 428. 1844. Prestonia sericea Mart. & Gal, Bull. Acad. Brux. lli; 360. [My?] 1844. Mitozus mexicanus Miers, Apoc. S. Am. 225. 1878. Exothostemon sericeum Miers, Apoc. S. Am. 241. 1878.
Fruticose or suffruticose liana, ferruginous-pubescent throughout; leaves firmly membranaceous, broadly ovate to oval or ob ovate-elliptic, 7-23 cm. long, 4-15 cm. broad, acute to very abruptly and shortly acuminate, rounded to obscurely cordate at the base, hispid-hirtellous to scabridulous above, densely tomentose beneath, the petioles 3-9 mm. long, tomentose; inflorescence closely subumbellate, simple, bearing 8-20 yellowish flowers; peduncle much shorter than the subtending leaves; pedicels 5-10 mm. long, tomentulose; bracts ovatelanceolate, 6-17 mm. long, foliaceous; calyx-lobes ovate-lanceolate to oblong-lanceolate, acute to acuminate, 12-23 mm. long, foliaceous, appressedtomentulose ; corolla salverform, ferruginous-villosulous externally, the tube 22-30 mm. long, 3-3.5 mm. in diameter at the base, the epistaminal appendages replaced by linear callose ridges, the lobes obliquely obovate, 13-15 mm. long; anthers glabrous, slightly exserted; nectaries concrescent, annular, broadly 5-lobed to essentially entire, about equaling or slightly surpassing the ovary; follicles stout and rigid, narrowly napiform, sharply divaricate, 6-12 cm. long, densely and rigidly f er ruginous-hisp id.
Type locality: Near Oaxaca, Oaxaca.
Distribution: Colima, Vera Cruz, Oaxaca, and Guatemala.

Prestonia isthmica Woodson, Ann. Mo. Bot. Gard
18: 555. 1931.
Fruticose or suffruticose liana, ferruginous-pubescent throughout; leaves firmly membranaceous, broadly obovate to oblong-elliptic, 9-22 cm. long, 5-13 cm. broad, abruptly and shortly acuminate, obtuse or rounded at the base and obscurely cordate, minutely and rather sparsely hirtellous-strigillose above, minutely tomentulose beneath, the petioles 3-12 mm. long, finely tomentulose; inflorescence densely subumbellate, simple, bearing 4-12 rather large yellowish flowers, the peduncle much shorter than the subtending leaves, finely tomentulose; pedicels 5-10 mm. long, minutely tomentulose-papillate; bracts ovate-lanceolate, 7-12 mm. long, foliaceous; calyx-lobes ovate to ovate-lanceolate, acuminate, 20-25 mm. long, foliaceous, minutely and rather irregularly hirtellous-papillose externally; corolla salverform, villosulous externally, the tube 25-35 mm. long, 3-4 mm. in diameter at the base, the epistaminal appendages replaced by callous linear ridges, the lobes obliquely obovate, 13-17 mm. long; anthers glabrous, slightly exserted; nectaries concrescent, tubular or subtubular, deeply 5-lobed, conspicuously surpassing the ovary ; follicles stout and rigid, narrowly napiform, sharply divaricate, 7-12 cm. long, densely and rigidly ferruginous-hispid.
Type locawty: Between Aserri and Tarbaca, San Jofi6, Costa Rica. Distribution: Costa Rica.

Prestonia mexicana là một loài thực vật có hoa trong họ La bố ma. Loài này được A.DC. miêu tả khoa học đầu tiên năm 1844.