Monstera dissecta (Araceae)
Epiphyte to 10 m tall, the leaves borne in a cluster at the top of the stem. Juvenile: terrestrial creeper, internodes 1- 6 cm long, leaves exserted and erect, petiole vaginate for ½ to 5/6 its length, the sheath wings persistent; lamina ovate to lanceolate, 3 – 5 times longer than broad, falcate, coriaceous, the base acute, the tip acute, glossy adaxially, slightly unequal; earliest leaves entire, rarely followed by several leaves with 1 – 4 perforations before the elaboration of pinnatifid leaves, more commonly going from entire to pinnatifid leaves without bearing perforate leaves. Adult stem: elliptic in cross section, green or brown, smooth to slightly papillose, 1.5 – 3.0 cm thick, 2.0 – 4.0 cm across, the internodes 1.0 – 3.5 cm long; the leaves borne in a cluster at the apex of the stem, leaf scars shallow, less than 2.0 cm wide at the widest point, encircling the stem with the ends of each scar overlapping for 0.5 – 1.0 cm, the lower part terminating behind the axillary bud of the preceding leaf; axillary bud 6 – 8 mm wide, about half as tall, in a depression on the stem. Petiole: smooth, 35 – 75 cm long, about equal in length to or somewhat shorter than the lamina, vaginate nearly to the lamina base or on the largest leaves to within 7 cm of the lamina base, the wings persistent; the geniculum 3 – 5 cm long. Lamina: coriaceous, glossy adaxially, ovate, about twice as long as wide, 40 – 70 cm long, 20 – 40 cm wide, pinnatifid, the pinnae 4 – 12 in number on each side, with 1 – 4 primary lateral veins per pinna, the total number of primary lateral veins 10 – 20, arising at an angle of about 80 degrees with the midrib near the leaf base, arising at an angle of 30 – 60 degrees above the base (rarely 60 – 80 degrees), the pinnae acuminate; the base of the lamina acute to truncate, unequal, the apex acuminate. Peduncle: smooth, green toward the apex, white at the base, elliptic in cross section, 1.0 – 1.6 cm thick, 1.3 – 2.5 cm across, 12 – 27 cm long, at least 1 cm longer than the spadix. Spathe: white, 15 – 25 cm tall, constricted 5 – 8 cm below the apex, acuminate, when fully open the margins 4 – 8 cm distant. Flowering spadix: white, 1.8 – 2.0 cm thick, 7 – 16 cm long, cylindric or slightly tapering, the flowers near the base sterile, the fertile pistils prismatic, truncate at the apex. Fruiting spadix: green, becoming pale yellow at maturity, 10 – 18 cm long, 3.5 – 4.5 cm thick, berries about 1 cm across. Seeds: brown, 8 – 10 mm long, 4 – 5 mm wide, 3 – 4 mm thick.
Monstera [dissecta]* is most easily recognized by its regularly pinnatifid leaves borne in a tight head at the apex of the stem. It occurs either in dark forests or exposed situations. It is readily distinguished from M. tenuis and M. spruceana by the exserted juvenile leaves, the peduncle exceeding the flowering spadix, the leaves borne in a tight head, and the petiole nearly equalling the lamina. In addition, these two other species have pinnae arising nearly at right angles to the costa, whereas in M. [dissecta] the pinnae generally arise at an angle of 30 – 70 degrees. Monstera subpinnata is distinguished from M. [dissecta] by the pinnae being constricted at the base and arising at a wide angle, and by the pistil that is prolonged into a conical, rather than truncate, style.
*Madison used the name Monstera dilacerata (K. Koch & H. Sello) K. Koch for this species, but this was later corrected by Croat & Grayum, Ann. Missouri Bot. Gard. 74(3): 659 (1987).