Aiphanes weberbaueri Burret

  • Authority

    Borchsenius, Finn & Bernal-González, Rodrigo. 1996. Aiphanes (Palmae). Fl. Neotrop. Monogr. 70: 1-94. (Published by NYBG Press)

  • Family

    Arecaceae

  • Scientific Name

    Aiphanes weberbaueri Burret

  • Type

    Type. Peru. Huánuco: Río Pozuzo, 1700 m, 20 Jul 1913 (fl), Weberbauer 6775 (holotype, B ; lectotype, here designated, F; isotypes, GH, MOL n.v., S).

  • Synonyms

    Aiphanes tessmannii Burret

  • Description

    Species Description - Solitary, rarely with a few suckers at base. Stem 0-1.5 m tall, 3.5-6 cm diam., armed with black spines on the internodes, to 5 cm long. Leaves 5-13, spreading; sheath 15-42 cm long, armed with black spines, to 5 cm long; petiole 10-46 cm long, green, armed like sheath, but spines fewer; rachis 55-120 cm long, green, almost glabrous to densely yellow or black spinulose, armed with scattered, black spines, to 4 cm long; pinnae 6-24 per side, inserted in groups of 2-3 separated by spaces of up to 13 cm, often subregularly inserted on the distal half of the leaf, sometimes regularly inserted throughout, more or less in one plane, linear to cuneate, 2.5-15 times as long as wide, oblique or incised praemorse at apex, with an up to 4 cm long finger-like projection on the distal margin, both sides nearly glabrous to densely covered with yellow or black spinules, up to 5 mm long; basal pinnae 7-21 x 0.5-4 cm; middle pinnae 12-30 x 2-7 cm; apical pinnae 3-7 ribbed, 8-28 x 5-20 cm. Inflorescence interfoliar, erect to curving, branched to 1 order; prophyll 15-33 cm long, 0.5-2.5 cm wide; peduncular bract 60-105 cm long, 1.5-2.5 cm wide, unarmed or spinulose, thin, soon disintegrating; peduncle 30—115 cm long, 2-7 mm diam. at junction with rachis, covered with thin, <1 cm long spines and spinules, these shorter distally; rachis 6-30(-60) cm long, densely covered with short, <1 mm long, yellow to brown spinules; rachillae 5-34, often inserted at relatively large intervals, with spinules like the rachis; basal rachillae 8-35 cm long, sometimes with an up to 8 cm long basal sterile portion, the fertile part with triads for ca. ½ of the length, in this part 2-5 mm diam., often distinctly thickened, especially in fruit, distal half 1-2 mm diam., staminate; apical rachillae 2-17 cm long, staminate; flower groups inserted in shallow depressions in the rachillae, pistillate flowers sometimes sunken for up to ½ of their length. Staminate flowers purple, 1-2 x 1-2.5 mm; sepals narrowly triangular to broadly ovate, arched, carinate, nearly enclosing the petals in bud, 1-1.5 x 0.5-1.5 mm; petals ovate-acute, briefly connate at base, 1.3-3 x 1.5-2.5 mm; filaments 0.3-0.5 mm long, anthers oval, 0.3-0.9 x 0.4-0.9 mm; pistillode sunken into the 0.4-0.7 mm thick receptacle. Pistillate flowers 2-4 mm long, 2.5-6 mm wide; sepals broadly ovate, nearly as long as the petals, imbricate, 2.5-3 x 4-5 mm; petals connate for ½-2/3 of their length, valvate distally, 3.5-4.5 x 3-4 mm, valves rounded, recurved at anthesis; staminodial cup 2.5-3.5 mm tall, nearly truncate; pistil ca. 3 mm high, glabrous. Fruits red to purple, globose to slightly elongate 7-10 mm diam.; endocarp 6-9 mm diam., shallowly pitted.

  • Discussion

    Aiphanes weberbaueri is characterized by its solitary, often more or less acaulescent habit, inflorescences with few (5-34), often thick rachillae, and pistillate flowers with completely reflexed, rounded petals and truncate staminodial cup, lending a very characteristic appearance to inflorescences with pistillate flowers in or past anthesis. It is closely related to A. deltoidea; the differences are discussed under that species.

    Aiphanes weberbaueri is a complex and incompletely known species. In the Andes, variation appears to be limited. Plants from this area have linear to narrowly cuneate, grouped to regularly inserted pinnae, and inflorescences with relatively few (13-30), often very thick rachillae. In the Amazon the species is more variable, and two forms can be recognized: one with linear, regularly inserted pinnae and inflorescences with ca. 30 slender rachillae (A. tessmannii Burret); and one with cuneate pinnae inserted in pairs or triplets, and inflorescences with 5-10 rachillae that are thickened in the androgynous part. The type of A. tessmannii is destroyed, and no isotypes exist. When the type locality was visited in May 1990, only one sterile individual was found and collected (Kahn & Borchsenius 2546, neotype). This plant was very conspicuous in its regularly pinnate, long-spinulose leaves, and appeared to be clearly distinct from the many individuals of the form with cuneate pinnae growing at the same locality. Plants with subregularly or regularly inserted, long-spinulose pinnae of similar size and shape are, however, known from the Andes (Borchsenius & Pedersen 94427, Moore 8527), and the latter specimen includes an inflorescence corresponding well to Burret’s description of the inflorescence of A. tessmannii. Thus, in reality, it is impossible to separate A. tessmannii from A. weberbaueri, at least with our present knowledge. The matter should be reinvestigated when more information becomes available.

    The existing material from Peru is insufficient to resolve the taxonomy of A. weberbaueri sensu lato in a satisfactory manner. The variation pattern resembles that found in A. hirsuta, which is still incompletely understood despite the fact that there exist more than twice as many, and more complete, collections of that species. Both show the same transition from linear, regularly inserted pinnae to cuneate, grouped ones, variation in indument and apex shape of the pinnae, and variation in number, length, and degree of thickening of the rachillae. Also, both species seem to occur in distinct sympatric forms in some areas, whereas differences break down in other.

    Distribution and Ecology: Eastern Andean slopes from southern Ecuador to southern Peru up to 1950 m, extending into the Amazonian lowlands in northern Peru as far as Iquitos. At the confluence of Río Santiago and Río Marañon the species grows on lateritic soil, around Iquitos and Río Nanay it is found on white sand, but morphological differences correlated with these differences in habitat are not evident.

  • Common Names

    chontilla

  • Distribution

    Ecuador South America| Morona-Santiago Ecuador South America| Pastaza Ecuador South America| Peru South America| Amazonas Peru South America| Junín Peru South America| Loreto Peru South America| Pasco Peru South America| San Martín Peru South America|