Grias subbullata Cornejo & S.A.Mori
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Family
Lecythidaceae (Magnoliophyta)
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Scientific Name
Grias subbullata Cornejo & S.A.Mori
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Primary Citation
Brittonia 63: 474 (-477, fig. 3). 2011
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Type Specimens
Specimen 1: Isotype -- X. Cornejo 8084
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Description
Autor: Xavier Cornejo & Scott A. Mori
Type: Ecuador. Santo Domingo de los Tsáchilas: Otongachi, premontane wet forest, secondary, 78° 57' 21.96" W 00° 19' 4.14" S, 900 m, 21 Jan 2009 (fl), X. Cornejo & A. Guasti 8084 (holotype, GUAY; isotypes, AAU, K, MO, NY, QCA, QCNE).
Description: Pachycaulous, monocaulous or once-branched, understory trees, 2-10 m × 4-13 cm, the trunk cylindrical, not buttressed. Bark smooth. Stems glabrous, the leaf-bearing one to 25 mm diam. Leaves: petioles absent or scarcely developed, suborbicular to broadly elliptical in cross-section, densely pubescent; blades oblanceolate to oblanceolate-spathulate, 70-150 × 17-38 cm, coriaceous, subbullate and glabrous adaxially, densely pubescent, especially on veins abaxially, the trichomes simple, laterally flattened (when dry), whitish, apparently without punctations abaxially, the base long tapering, the margins entire, the apex narrowly- to broadly-obtuse or acuminate; venation brochidodromous, the secondary veins in 34-64 pairs, the tertiary veins prominent, percurrent, the higher order veins reticulate, ± salient. Inflorescences cauline, racemes or subfasciculate, with up to 4 flowers, the rachis densely pubescent, 1-3 × ca. 2 mm; pedicels 3-7 × ca. 1 mm, tomentulose to densely pubescent, subtended by a single triangular bract, ca. 1-1.5.x 1-1.5 mm, bracteoles not apparent. Flower buds ovate; mature flowers 4-6.5 cm diam.; hypanthium ca. 5 x 4 mm (ca. 3 x 2.5 mm when dry), densely pubescent; calyx splitting in 3 or 4 lobes at anthesis, the lobes fused at bases to form calycine rim above apex of ovary, the lobes hemiorbicular to subovate, ca. 5-6 × 5 mm, light-green, puberulous to glabrous abaxially; petals narrowly elliptic, oblong, or obovate, 2.3-3 × 1.3-1.6 cm (slightly smaller, ca. 1.7-2. x 0.5-0.8 cm, when dry), sometimes arching downward at apex and widely spreading at anthesis, yellowish to cream, sometimes reddish-pink at bases; androecium obloid, appearing somewhat square when viewed apically, the staminal tube 1-2 mm high, divided into 2 chambers, arching from base to apex abaxially, the lower chamber erect adaxially, the upper chamber slanting outward, with 40-55 stamens, the filaments somewhat slightly constricted at apex, the outermost 8-10 mm long, the connectives absent, the anthers suborbicular, ca. 1 mm long, dehiscence introrse; ovary 4-locular, with ca. 2 ovules per locule, the summit truncate, green, a nectary disk absent, the style ca. 0.8 mm long. Fruits obovate, green turning brown, 7.5-9 × ca. 5 cm, longitudinally subcostate and abundantly brown-lenticellate when fresh at maturity, the mesocarp yellow, ca. 10-13 mm thick. Seeds ca. 65 x 30 mm.
Common names: None recorded.
Distribution: Known only from two small populations located in Santo Domingo de los Tsáchilas province, northwestern Ecuador between 900 and 1670 m elevation. The populations are separated from each other by ca. 10 km. The type locality, in the private Reserva Otongachi, is located along the Santo Domingo-Quito highway; and the other population is fouind in the Bosque Protector Lelia. It is most likely that additional populations of this species may inhabit the forested tops of mountains and hills located in the same area.
Ecology: This species is a small understory tree of premontane to lower montane wet forests where it has been observed to trap litter within its terminal rosette of leaves. It is sympatric with other trees endemic to the wet forests of W Ecuador such as Browneopsis macrofoliolata Klitgaard (Fabaceae), Croizatia cimalonia Cerón & G. L. Webster (Euphorbiaceae), Heisteria asplundii Sleumer (Olacaceae), Pentagonia clementinensis Cornejo (Rubiaceae), and Meliosma gracilis Cornejo & Bonifaz (Sabiaceae) (Cerón & Webster, 2002; Jørgensen & León-Yánez, 1999).
Phenology: Flowers have been collected in Jan and Nov during the rainy season; and fruits have been found in Nov. The rainy season in that area occurs from Oct to Mar and the dry season is from Apr through Oct.
Pollination: Melipona bees have been observed visiting the flowers but we do not think that they are the pollinators of this species which, because of the aroma that some other conspecifics produce, may be beetles (Knudsen & Mori, 1996). There are, however, no published studies of the pollination of any species of Grias so this suggestion needs to be confirmed with field studies.
Dispersal: As in all species of Grias, it is most likely that the fruits of G. subbullata, once fallen to the ground, are dispersed by rodents.
Predation: Based on our observation of other species of Grias, we conclude that mammals and insects may be involved in the predation of this species.
Field characters: This species is separated from all other species of Grias by the combination of subbullate adaxial leaf blade surface; prominent secondary and tertiary veins abaxially; reduced rachis; short pedicels; dense hypanthial and calyx-lobe pubescence; white petals often with reddish-pink at their bases; and divergent anther thecae. The leaves of sterile collections appear more like the leaves of a species of Gustavia than a species of Grias. It is also the most pubescent species of this genus.
Taxonomic notes: Because of the prominent secondary and tertiary veins abaxially, the leaf blades of this remarkable new species resemble some species of Gustavia L. It is distinguished from that genus by flower and fruit characters (e.g., calyx-lobes fused at their bases to form a distinct versus absent calycine rim; filaments angular versus round in cross section, longitudinal vs. poricidal anther dehiscence, four versus six or more petals, few versus many ovules per locule, and fruits obovate containing a longitudinally 8-ridged seed versus subglobose and containing several smooth to superficially net-like veined seeds. In addition to the salient venation abaxially, G. subbullata differs from other species of Grias by the leaf blades, which are pilose abaxially and subbullate adaxially, tomentulose to densely pilose pedicels and hypanthia externally, and fruits green at maturity. The very short pedicels of Grias subbullata are only similar in length to those of the distantly related G. theobromicarpa Cornejo & S.A. Mori, another local endemic only known from the wet forests of Pichincha Province, Ecuador, at ca. 1500 m. However, G. subbullata is also differentiated from G. theobromicarpa by the staminal tube (poorly vs. strongly developed), shorter anthers (1 versus 3-4 mm long), anther dehiscence (lateral versus longitudinal-ventral), and fruits green, subcostate, and obtuse to rounded at base (versus fruits irregularly green and brown variegated, prominently 8-ridged, and cuneate at base, Cornejo & Mori, 2010).
Conservation: Mature individuals of Grias subbullata are mostly found in the interior of forests. Very few individuals remain as scattered treelets intermixed with native trees of several other species in open areas and pastures near to less disturbed forests . Seedlings and juveniles of G. subbullata have been observed only in the interior of forests, but never growing in the deforested areas nearby. Based on these field observations, we suspect that the seeds of this species have a narrow range of tolerance for disturbances and, therefore, are not able to germinate in open areas. In addition, because the remaining forest populations of G. subbullata are threatened by continuous selective logging, deforestation for logging and other purposes, and agricultural expansion we suggest that Grias subbullata be assigned the IUCN conservation status of endangered, EN B1ab(iii) (IUCN, 2001).
Uses: None recorded.
Etymology: The epithet refers to the sub-bullate adaxial surface of the leaf blades, which is unknown for other species of the genus.
Source: Cornejo, X. & S. A. Mori. 2011. Eschweilera awaensis and Grias subbullata (Lecythidaceae), two new species from northwestern Ecuador. Britonia 63.
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Floras and Monographs
Grias subbullata Cornejo & S.A.Mori: [Article] Cornejo, Xavier & Mori, S. A. 2011.
and (Lecythidaceae), two new species from northwestern Ecuador. Brittonia. 63 (4): 469-477. -
Narratives
