Couratari macrosperma A.C.Sm.
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Description
Author: Scott A. Mori, Ghillean T. Prance, & Nathan P. Smith
Type: Brazil. Rondônia: Tabajara, Rio Machado region, Nov-Dec 1931 (fr), Krukoff 1513 (holotype, NY; isotypes, A, BM, F, G, K, MICH, MO, P, S, U, US, WIS).
Description: Trees, to 50 m tall, the trunk buttressed, often low and thick, sometimes to 4 m. Bark with shallow, vertically oriented fissures. Stems puberulous when young, soon becoming glabrous with age. Leaves: petiole 5-9 mm long, tomentellous to glabrescent, canaliculate, markedly winged; blades oblong to oblong-Ianceolate, 8.5-17.5 x 2.5-7.5 cm, with longitudinally oriented parallel striations most common along striations, chartaceous, pubescent abaxially, with two types of shortly stalked stellate hairs, the larger type sparse, 29 times larger than smaller type, the smaller type dense, especially on newly flushed leaves, more common along striations, the base cuneate, the margins entire but slightly undulate, very sparsely ciliate when young, the apex acute to shortly acuminate; midrib prominulous and glabrous adaxially, prominent, with a few scattered appressed hairs abaxially, the secondary veins in 21-27 pairs, prominulous on both surfaces, the tertiary venation slightly prominulous. Inflorescences terminal or axillary, racemes 10-30 cm long, the rachis stellate-tomentellous; pedicels tomentellous, articulate, 2-6 mm long below articulation and 1-4 mm long above articulation. Flowers: hypanthium campanulate, 5-8 mm long; calyx lobes oblong-rounded, ca. 8 mm long, tomentellous on both surfaces, the margins ciliate; petals obovate, ca. 2 cm long, puberulous abaxially, almost glabrous adaxially, white, the apex apex; androecium ca. 3.5 cm long, the staminal ring ca. 15 mm diam., the stamens inserted evenly around ring, the exterior of hood with numerous echinate appendages, white to yellowish; ovary 3(4)-locular. Fruits cylindrical, rounded in cross section, broadest at about middle or at calycine ring, 12-15 x 7 cm, the pericarp crustaceous on exterior, ca. 4 mm thick, hard and woody, the calycine ring 3-15 mm below apex, the sepals prominent, forming distinct 6-partite ridge around calycine ring, the operculum not radially grooved, centrally concave or convex, the columella markedly triangular and longitudinally striate, the pericarp 8-10 mm thick. Seeds oblong-lanceolate, symmetrical, 8-10 x 3 cm, notched at micropylar end, rounded to truncate at distal end.
Common names: Brazil: Tauari (Amazonia).
Distribution: Disjunct between south central and southwestern Amazonia from Acre to Amazonas and the coastal forests of eastern Brazil. The collection from Pará, Brazil (Vasconcelos et al. 308), a flowering collection compares well with specimens from western Amazonia, and the collection from Colombia (collector unknown no. 151) is sterile but also appears to represent this species.
Ecology: Trees of non-flooded forests.
Phenology: Collected in flower from Jul to Oct.
Pollination: No observations recorded but bees have been observed visiting the flowers of the closely related Couratari stellata (Mori & Boeke, 1987). The attached image of Daly 7103 shows what appears to be nectar in the inner chamber of the androecium.
Dispersal: The circumferentially winged seeds are dispersed by the wind.
Predation: Macaws tear open the fruits and eat the seeds (fide Mori et al. 25635). See image attached to this page.
Field characters: This species is characterized by the consipicuous striations that run parallel to the margins of the leaf blades; the white petals and white or light yellow, echinate hoods, and the very large fruits.
Taxonomic notes: This species belongs to Couratari sect. Echinata which includes the following species: C. asterophora, C. asterotricha, C. macrosperma, C. pyramidata, C. scottmorii, C. stellata, and other not yet described species. This section is characterized by an echinate androecial hood (see images of the androecium on the species pages of C. macrosperma, C. scottmorii, and C. stellata). Prance (1990) also notes that the species possess short pedicels and sessile fruits with well developed calyx scars. In addition, the flowers of these species are not produced when the trees are leafless, have white petals, white to yellowish androecial hoods, and the pubescence of the inflorescence rachises and hypanthia are yellowish-brown in color. There is no sign of the pink to purple flower coloration and leaf fall just before flowering found in the other two sections of the genus (sects. Couratari and microcarpa). The pubescence of species of sect. Couratari is purple tinged and the species of sect. microcarpa are glabrous. The species of sect. Echinata form a superspecies (Prance in Mori & Prance, 1990) and are difficult to distinguish from one another. In addition, Several of the species, especially those from eastern Brazil, where four of the six species occur, are known from relatively few collections; thus, it is not yet possible to say if the differences among them provided in their protologues merit recognition at the species level. Couratari macrosperma is closely related to C. stellata from which it is separated by the more robust leaf-bearing stems, very conspicuous vs less conspicuous longitudinal striations of the leaf blades, larger leaf blades, the markedly vs. less conspicuously winged petioles, and the much larger fruits. Couratari krukovii, which was described because of slight differences in the pyxidium, cannot be regarded as distinct in light of the variation displayed by fruit collections of this and many other species of Lecythidaceae. At the time of the publication of the Prance (1990) an eastern Brazilian population morphological similar to C. macrosperma was considered to be part of this species. This population has markedly smaller fruits, a thinner pericarp, and a very flat petiole cross section and is curently treated as un unpublished new species represented by Folli 6473. See the specimen catalog of this collection for images of this species.
Conservation: IUCN Red List: not on list (IUCN, 2009). Plantas Raras do Brazil: not on list (Giulietti et al., 2009).
Uses: None recorded.
Etymology: The species epithet refers to the very large seeds and, by extension, the large fruits.
Source: Based on Prance in Mori and Prance (1990).
Acknowledgements: We are grateful to D. Daly and T. Paine for allowing us to use their images to illustrate the characters of this species.
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Floras and Monographs
Couratari macrosperma A.C.Sm.: [Article] Mori, S. A. & Prance, Ghillean T. 1990. Lecythidaceae - Part II: The zygomorphic-flowered New World genera (Couroupita, Corythophora, Bertholletia, Couratari, Eschweilera, & Lecythis). With a study of secondary xylem of Neotropical Lecythidaceae by Carl de Zeeuw. Fl. Neotrop. Monogr. 21: 1-376.
