Allantoma lineata (Mart. ex O.Berg) Miers
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Family
Lecythidaceae (Magnoliophyta)
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Scientific Name
Allantoma lineata (Mart. ex O.Berg) Miers
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Primary Citation
Trans. Linn. Soc. London 30: 297. 1874
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Basionym
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Description
Author: S. A. Mori & G. T. Prance
Type: Brazil. Pará: Colares Island, no date (fr), Poeppig 3036 (holotype, W; isotype, B, lost; isotype fragment, F).
Description: Understory to canopy trees, 8-10(20) m tall, the trunk cylindrical. Bark smooth, gray or marron, lenticellate, the outer bark thin, the inner bark ca. 10 mm thick, reddish. Stems glabrous when young. Leaves present at flowering; petioles 12-20 mm long, canaliculate, glabrous, not winged; blades ovate to oblong lanceolate, but usually oblong, (10)12-20(29) x 5.0-11.5 cm, glabrous on both surfaces, the base rounded to subcuneate, the margins entire, very slightly revolute, the apex long-acuminate, the acumen 10-20(30) mm long; venation eucamptrodromous throughout, the midrib plane (toward base) to prominulous toward base adaxially, prominent abaxially, the secondary veins in 18-25 pairs, turning abruptly downward at junction with midrib and descending for a short distance along midrib, plane to slightly impressed adaxially, prominent abaxially, the tertiary veins very fine, scarcely visible at first glance, percurrent, plane ad- and abaxially. Inflorescences usually terminal or less frequently subterminal, unbranched spikes or once-branched panicles or clusters of spikes, the rachises conspicuously lenticellate; bracts lanceolate, ca. 2 mm long, membranous, caducous; pedicels not apparent, not developed below articulation and difficult to distinguish from hypanthium above articulation, glabrous. Flowers: hypanthium campanulate, ca. 7 mm long, the lobes 5-6 indistinct, scarcely divided, triangular, glabrous abaxially, calycine rim present; petals 5, oblong, fleshy, hooked at apices, white to pale yellow; staminal tube thick, to 10 mm long, glabrous, the rim of tube divided into 8-10 inwardly reflexed stamens, the stamens also arising from different levels inside tube, also reflexed; ovary (3)4(5) locular, truncate at apex, the ovules numerous, attached throughout length of lower septum, horizontally oriented; style short. Fruits mostly cylindrical, but sometimes somewhat campanulate, sometimes slightly curved, especially when young, 7-18 x 3.5-6.5 cm, the pericarp not markedly ridged, often cracking irregularly when dry, the calycine ring 5-10 cm below apex, the operculum truncate, convex, or concave at apex, the columella persistent, 5-12 cm long, the apex truncate, convex, or deeply concave, not umbonate. Seeds narrowly linear-elongate, ca. 5-6 cm long, notched at base at maturity, somewhat angled, vestigial seed wing present when immature, absent at time of dispersal, the seed coat verrucose.
Common names: Venezuela: Tabari. Brazil: Ceru, cheru, churu, and xuru. Tauarí is sometimes applied to this species but that name is more appropriately used for species of Cariniana and Couratari and should be abandoned for this species.
Distribution: Only known from Venezeula where it has been collected from the southern part of the country and Brazil where it is known from the Rio Negro basin and from Manaus to the mouth of the Amazon River in the state of Pará (click on "map all specimens of this taxon" to see a distribution map).
Ecology: A medium-sized tree of periodically flooded forests of both the várzea (flooded by white water) and igapó (flooded by black water) types (see Fig. 22 in Prance & Mori, 1979 for a local distribution of this species in relation to flooded and non-flooded habitats). Also found in wet habitats along small streams within terra firme forest. Some collectors have indicated that A. lineata can be a dominant tree species in areas where they have collected it and Ducke (1925) observed that it was frequently observed when passing through the Breves canals in June because of the deep purple leaves flushing at that time of year.
Phenology: In Brazil, flowering specimens have been gathered in most months of the year thereby indicating that some individuals of this species can be found in flower throughout the year, but most flowering collections have been made in Oct and Nov at the time of low water level (Kubitski & Ziburski, 1994) throughout most of the distribution of A. lineata. In Venezuela, collections have been made from Jun through Nov. Because the fruits are woody and collected when they are immature, empty in trees or on the ground, or when mature; it is difficult to determine at what time of year seeds are released. The only collections we have seen with nearly or fully mature seeds were made in Jan, Feb, Mar, and Nov in central Amazonian Brazil (Prance et al. 11618), and in Jan and Sep in Venezuela.
Pollination: No pollination observations have been made on this or on any other species of Allantoma. Prance and Mori (1979) mentioned that because of their smaller flowers, the pollinators of species of Allantoma must be relatively small insects, but did not stipulate what insects they might be. The flower structure of species of Allantoma are most similar to species of Grias which have been suggested to be pollinated by beetles because the aroma of Grias peruviana is dominated by fatty acid derived esters, a compound frequently found in beetle pollinated species of other families (Knudsen & Mori, 1996). We now suspect that not all species of Grias, however, are necessarily pollinated by beetles (Mori et al., 2010). Although Prance and Mori (1979) indicate that the pollinators of Allantoma and Grias probably do not seek nectar and, thus, the pollinators gather pollen as the reward may not be true. We now believe that nectar should not be ruled out as the reward offered by the species of these two genera because the staminal tube may be an adaptation for holding nectar for its pollinators.
Dispersal: Allantoma lineata has water dispersed seeds which are released during the river's annual crest. However, as Kubitzki and Ziburski (1994) point out, practically any fruits or seeds that fall into the water may also be dispersed by fish. After fruit dehiscence the seeds drop directly into the water where they float because of their high oil content (Ducke, 1948). Flotation experiments demonstrate that seeds of A. lineata float and remain viable for at least 3 months (Prance in Prance & Mori, 1979). Terra firme species of Allantoma have unilaterally winged seeds (e.g., see a winged seed of A. decandra on its species page and in Ducke, 1925, pl. 16f) in contrast to those of A. lineata which only have vestigial wings. At the time of dispersal the seeds of A. lineata have lost the vestigial wings but the notches where they were attached are still obvious. Two other species, A. pluriflora and A. uaupensis may also have vestigial seed wings but that needs to be confirmed. Tsou and Mori (2002), in an anatomical study of the seeds of Allantoma lineata, found that the outers cells of the testa are elongated and papillate and suggested that this may help to trap air and facillate water dispersal. The unilateral seed wings of Cariniana are never vestigial and, thus, all species of that genus are dispersed by the wind.
Predation: Several herbarium collections of fruits have been gnawed open by unknown animals.
Field characters: Allantoma lineata is a small- to medium-sized tree mostly growing closely associated with wet habits. The trunk is cylindric, the bark is smooth but with lenticels, the outer bark is much thinner than the inner bark and the latter is reddish in color as seen when it is cut with a machete. The leaves are medium-sized in relation to other species of the genus, some of which are smaller (e.g., A. decandra) and others are larger (e.g., A. pluriflora). The inflorescences are unbranched or once-branched clusters of spikes. This is the only known species of Lecythidaceae with elongate buds. The flowers, which have white or yellow petals, have the longest staminal tube known for the genus. The fruits are cylindric, the pericarp is smooth in contrast to the ridged or even sulcate pericarps of most other species. The seeds only have a vestigial wing which is lost before dispersal (leaving a distinctive notch at the end where it was attached). The seed coat of this species is rough.
Taxonomic notes: Like in other species of Lecythidaceae, the fruits of Allantoma lineata (locule number, pericarp surface, size, shape) are variable and can not be used to separate species reliably (Prance in Prance & Mori, 1979). When the Flora Neotropica monograph was published (Prance & Mori, 1979) only one species was recognized in Allantoma, but Huang et al. (2008) demonstrated that some of the species of Cariniana were actually species of Allantoma and transferred them to Allantoma which now includes seven species.
Uses: Melo and Alves (1974), in a study of seven Amazonian species of trees in six families, found that Allantoma lineata has excellent properties for making paper pulp. Nevertheless, because the density of trees of this species is not sufficient for economically harvesting trees for paper pulp, it would not be practical to harvest pulp wood from this species. In addition, the ecosystem services provided by the periodically flooded forests where A. lineata grows are more valuable than the pulp that could be derived from replacing these forests with tree plantations. The seeds of this species are edible and known as "skittle-nuts" which are only harvested for local use. The laminated inner bark has been used for making cigarette paper as has the bark of other species of Lecythidaceae, e.g., Lecythis corrugata.
Etymology: The origin of the species epithet is not known, but may refer either to the oblong fruits or to the narrowly oblong petals.
Conservation: This species is not on the IUCN Red List of Threatened Species (Version 2010.4) and is not listed in the Plantas Raras do Brazil (Giulietti et al., 2009).
Source: Based on Prance in Prance & Mori, 1979.
Acknowledgements: We are grateful to B. Blijenberg, C. Carollo, and M. Hopkins for allowing us to use their images to illustrate the characters of this species.
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Floras and Monographs
Allantoma lineata (Mart. ex O.Berg) Miers: [Article] Prance, Ghillean T. & Mori, S. A. 1979. Lecythidaceae - Part I. The actinomorphic-flowered New World Lecythidaceae (Asteranthos, Gustavia, Grias, Allantoma & Cariniana). Fl. Neotrop. Monogr. 21: 1-270.
Allantoma lineata (Mart. ex O.Berg) Miers: [Article] Mori, S. A. & Lepsch da Cunha, Nadia M. 1995. The Lecythidaceae of a central Amazonian moist forest. Mem. New York Bot. Gard. 75: 1-55.
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Narratives
SEM of a pollen grain of Allantoma lineata. Photo by J. Muller.
