Anthurium margaricarpum Sodiro

Epiphyte; stems 2–20 cm long; internodes 6–20 mm diam.; cataphylls 4–6 cm long, drying reddish brown, promptly weathering to fibers; leaves semi-erect; petioles 10–35 cm long, 3–4 mm diam., subterete, C-shaped, sharply flattened adaxially, sheathed 1–2 cm at base, the geniculum 5–15 (20) mm long, drying darker than the petiole; blades oblong-elliptic, 25–45 cm long, 4–11 cm wide, narrowly acute at apex, acute or sometimes obtuse at base, subcoriaceous, semiglossy, dark green and eglandular above, semiglossy and moderately paler and dark glandular-punctate below; midrib weakly raised convex and concolorous above, convex below; primary lateral veins (15)20–23 per side, departing the midrib at about a 45 degree angle; the collective veins arising from the base of blade or from one of the primary lateral veins in the lower 1/4 of the blade, extending to the apex 3.5–5.5 mm from the margin; antimarginal vein weak, 0.5 mm from the margin. Inflorescence semi-erect; peduncle 5–25(32) cm long, subterete, usually about half as long as the petiole; spathe oblong-lanceolate, 2–7(10) cm long, 4–7(14) mm wide, dark green tinged with red or purple, inserted at an angle of 50 degrees, recurved, cuspidate at the apex, the margins meeting at an obtuse angle at the base; spadix gradually tapered, sessile or stipitate 1–2 mm, dark green at anthesis, 5–15 cm long, 5 mm diam.; flowers quadrangular in outline, 5 visible per spiral, 2–2.6 mm long (in direction of axis); the inner margins of the tepals 1–1.6 mm wide; stamens held at level of tepals; anthers yellow, pollen soon white; pistil to 1.2 mm long, slightly longer than the stamens, broadly botuliforme; stigma sub-bilabiate; infructescence to 23 cm long, pendent, purplish violet; berries ovoid, purplish in upper half, whitish toward the base, maturing pale gray-white, primarily in the center of the spadix, mesocarp white and pasty; seeds 2, somewhat discoidal, 3.2 mm long, 2.2 mm diam.

Anthurium margaricarpum is apparently endemic to Ecuador, known at present only from the western slopes of the Andes on Volcán Pichincha at 650 to 1,600 m elevation. At Reserva ENDESA it is encountered in both the primary and secondary forest. It is characterized by its epiphytic habit, oblong-elongate blades which are dark glandular﷓punctate on the lower surface and epunctate on the upper surface. It is the only member of section Porphyrochitonium at ENDESA with blades which are epunctate on the upper surface. Sodiro described the species as having petioles which are deeply flattened-sulcate adaxially but this character is probably somewhat variable. Most collections actually do not mention the petiole cross-section but most appear to be at least sharply C-shaped, and it is easy to imagine that many might have deeply sulcate petioles. Anthurium margaricapum has been confused with A. andinum Engl., a poorly known species whose type specimen was collected in Cotopaxi, Mun. Pujilí, near Angamarca at 2,400 m elevation. It has similar blades but which differs in having glandular punctations on the upper surface and in having a purplish spadix (versus eglandular on the upper surface and in having a green spadix). At ENDESA reserve Anthurium margaricarpum is most easily confused with A. aureum. That species also differs in having blades glandular on the upper surface but it also differs in being terrestrial. Anthurium margaricarpum may also be confused at the reserve with A. cabuyalense which is an epiphyte with elongate leaf blades. It differs in having longer blades (72--80 cm long) which are 7.6--8 times longer than broad and only weakly glossy and somewhat velvety above. The species is perhaps most closely related to (or possibly inseparable from) a presumed new species represented by Croat 50665, 73028 and 73037 from Centinela in Los Ríos Province as well as Croat 73798 from near Pucayacu in Cotopaxi Province. That species looks very similar, at least in superficial terms, but has the upper blade surface subvelvety rather than semiglossy. A single collection, Rodríguez 212 from ENDESA, with much smaller vegetative and fertile parts and blades which dry with obscure brownish speckles on the upper surface (versus not speckled and with epidermal cells forming an areolate pattern on drying for A. margaricarpum) is tentatively placed here as well but may prove to be a distinct and new species. Palacios et al. 9771 from Carchí Province at more than 2,000 m may also be this species. Sodiro describes the spadix of A. margaricarpum as being stipitate 2--3 mm but none of our material (including any of the specimens annotated by him have a spadix stipitate on the back side more than 1--2 mm. Perhaps his measurements were based on fresh material and some shrinkage has resulted from drying. Only two Sodiro collections exist which specifically mention Gualea. Of these, the collection at the herbarium of Instituto Darwinion (SI) is clearly the most complete, with stems, an inflorescence and leaf blades of three sizes. It was therefore chosen as the lectotype.