Descripción: Árbol de 2 a 7 m de alto. Tronco y ramas con espinas. Corteza exterior blanca o gris. Hojas simples y alternas, de 3-11 x 2-5 cm, oblongas o elípticas, con ápice acuminado, agudo o redondeado, bordes dentados y base redondeada. Las hojas presentan puntos translúcidos. Estípulas pequeñas, triangulares y deciduas, pero persistentes en los ápices de las ramitas. Pecíolo de 0.5-1.5 cm de largo. Flores blancas. Frutos en cápsulas globosas, de 0.5-1 cm de diámetro, verdes, tornándose rojos y dehiscentes en tres valvas al madurar. Semillas envueltas de un arilo rojo o anaranjado.

Datos Ecológicos: La especie crece a bajas elevaciones, en bosques secos o húmedos. En Panamá se encuentra en las provincias de Chiriquí, Colón, Darién, Herrera, Los Santos, Panamá y Veraguas. Florece y fructifica de marzo a junio. Las flores son visitadas por abejas y otros insectos.

Especies Parecidas: A menudo se confunde con LK xyl2pa Xylosma panamensis LK2 , pero en X. panamensis las espinas son ramificadas y los frutos son bayas.

Usos: El tronco se utiliza para postes de cercas, mangos de herramientas y leña.

Tree, ca 5 m tall; trunk ca 7 cm dbh, with simple spines near base; branches and branchlets glabrate to densely strigillose or puberulent; branches arching, wide-spreading, often with straight, stout, sharp branch-spines. Stipules deltoid to narrowly triangular, ca 2 mm long; petioles 2-8 mm long; blades ovate to elliptic or obovate or oblanceolate, acuminate to acute or rounded at apex, obtuse to attenuate and decurrent at base, 2.5-11 cm long, 1.3-4 cm wide, glabrous or with sparse, +/- appressed pubescence, weakly or not at all pellucid-punctate, the margins crenate-serrate, the teeth obscure to sharp, glandular and incurled. Fascicles sparse, sessile, axillary; bracteoles connate, sparsely pubescent, whitish to translucent, very thin, the outermost +/- triangular, very short, the inner ones oval, rounded at apex; pedicels 1.5-3 mm long, slender, to 3 mm wide when dried, sparsely villous, articulate at about middle, usually longer than bracteoles; flowers greenish-white, ca 7 mm diam; sepals 4-6, 3-3.5 (5.5) mm long, strigillose outside, blunt to rounded at apex, spreading at anthesis; corolla lacking; stamens 7 or 8 (9), ca 4 mm long, erect at anthesis, fused into a ring at base, alternating with densely villous staminodia, the staminal tube glabrous outside, pubescent inside; filaments +/- glabrous; anthers 1 mm. long, introrse, equaling height of style; pollen yellowish, +/- tacky; ovary sparsely villous, narrowly ovate; style short; stigma globular, viscid, short-puberulent. Capsules 3-valved, round to ellipsoid, to ca 1 cm long, pale green to white often marked with purple; valves maroon inside, marked with prominent white spots; seeds of irregular shapes, ca 4 mm long, enveloped in a pale orange aril. Croat 11777,13268, 14057. Occasional, in the forest. Flowers in March and April. The fruits mature from April to June. H. Sleumer considers Casearia stjohnii I. M. Johnston synonymous (pers. comm.); I consider it distinct (Croat, 1975b), though probably more closely related to C. aculeata than (as I had originally thought) to C. guzanensis. Casearia stjohnii flowers later than C. aculeata (June and July), with the fruits maturing during August and September. It also has thicker, longer inflorescence bracts and much stouter, more densely pubescent pedicels.