Cornejo, Xavier & Mori, S. A. 2011.
Lecythidaceae
Description - Species Griadis nova pagina bullata, inferiore dense pilosa tibus praedita; flores caulini tomentulosa. Unbranched or once-branched pachycau lous tree, 2.3-10 m tall, 4-13 cm dbh, the trunk cylindric to base. Stems thick with cordate leaf scars. Immature leaves subtended by conspicuous, large, folióse, pink cata phylls. Mature leaves clustered at apices of branches or stems; petioles absent or scarcely developed, suborbicular to broadly elliptical in cross-section made at base of leaf blade, the cross-section with lower arc of 6-7 suborbicular major bundles, upper arc of ca. 3 major bundles, these elliptic in outline (the inside mostly of parenchyma), the major bundles surrounded by abundant minor bundles, the pulvini brown, inconspicuous after drying; blades oblanceolate to oblanceolate spathulate, 70-150 x 17-38 cm, coriaceous, subbullate, dark-green, glabrous adaxially, paler green abaxially, pilose, especially on veins, the trichomes simple, linear-oblong, laterally flattened (when dry), and whitish, the blade apparently without punctations, the base long tapering, the margins entire, the apex narrowly- to broadly-obtuse and acuminate; venation brochidodromous, the midrib nar rowly carínate for most of length adaxially, longitudinally multi-sulcate, the secondary veins in 34-64 pairs in mature leaves, salient, ¿rounded adaxially, the tertiary veins prom inent, percurrent, joining the secondaries at 90° angles, the higher order ± salient. Inflorescen ces cauline from lower to middle part of trunk, the racemes very reduced, or subfasciculate, or flowers solitary, the rachis, when present, 1—3 x ca. 2 mm, bearing up to 4 flowers; floral bracts triangular, ca. 1—1.5.x 1—1.5 mm; pedicel 3-7 x ca. 1 mm, tomentulose to densely pilose, bearing 2 minute triangular bracts, ca. 0.7 x 0.7 mm, inserted on lower half of pedicel Flowers 4—6.5 cm diam. at anthesis; calyx splitting in 3 or 4 lobes, the lobes fused at their bases to form a rim above apex of ovary, hemiorbicular to subovate, ca. 5-6x5 mm, light-green, puberulous to glabrous abaxially; petals oblong-obovate, oblong-elliptic, or oblong, widely spreading at anthesis, rounded and sometimes arching downward toward apex, 2.3-3 x 1.3-1.6 cm (slightly smaller, ca. 1.7-2. X 0.5-0.8 cm, when dry), carnose (when fresh, but thinly membranaceous when dry), yellowish to cream at anthesis, glabrous; androecium actinomorphic, appearing some what square when viewed apically, the filaments carnose, angular in cross section, the outermost filaments 8-10 mm long, the stamens 40—55, inserted in three levels, all centripetally reflexed downward, creamish or yellowish, the anthers 1 mm long, the dehiscence lateral; ovary inferior, turbinate, ca. 5x4 mm (ca. 3 x 2.5 mm when dry), greenish and white-tomentulose to densely pilose, the summit truncate, green, the style ca. 0.8 mm long, the stigma with 4 stigmatic lines; ovary 4-locular, the ovules few in number, pendulous from near apex of septum, the fiinicle short, linear. Fruits on very short pedicels ca. 5 mm long, obovate, the base obtuse to rounded, the apex truncate, somewhat subcostate at maturity, 7.5-9 xca. 5 cm, green, abun dantly brown-lenticellate when fresh, the sepals not persistent; seeds one per fruit, the embryo white.
Distribution.-Known only from two small populations located in Santo Domingo de los Tsáchilas province, northwestern Ecuador between 900 and 1670 m elevation, and separate from each other by ca. 10 km. It is most likely that additional populations of this species inhabit the nearby forested mountains and hills.
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 trees endemic to the wet forests in W Ecuador such as Browneopsis macro foliolata Klitgaard (Fabaceae), Croizatia cima Ionia Cerón & G. L. Webster (Euphorbiaceae), Heisteria asplundii Sleumer (Olacaceae), Pentagonia clementinensis Cornejo (Rubia ceae), and Meliosma gracilis Cornejo & Bonifaz (Sabiaceae; Cerón & Webster, 2002; torgensen & León-Yánez, 1999).
Phenology.-Flowers have been collected during the rainy season in Jan and Nov (the senior author has observed several trees flowering in Jan and only a single tree with a single flower in Nov); 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 because the aroma of some other conspecifics is consistent with beetle polli nation (Knudsen & Mori, 1996). There are, however, no published studies of the polli nation of any species of Grias so these comments need to be confirmed with field studies.
Prédation.-The staminal filaments are partially eaten by Melipona bees when the flowers are still attached to trees.
Etymology.-The epithet refers to the sub bullate adaxial surface of the leaf blades, which is unknown in other species of the genus.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, longi tudinal vs. poricidal anther dehiscence, four versus six or more petals, few versus many ovules per locule, and fruits obovate, contain ing a longitudinally 8-ridged single seed versus subglobose and containing several smooth to superficially net-like veined seeds Cornejo & Mori, 2010). In addition to the salient venation abaxially, G. subbullata differs from other species of Grias by the leaf blades, which are pilose abaxially and sub-bullate adaxially, tomentulose to densely pilose pedicels and hypanthia externally, and fruits green at matur ity. 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 status.—Mature individuals of Grias subbullata are mostly found in the interior of forests. A few individuals remain as scattered treelets intermixed with native trees of several other species in open areas and pastures adjacent to old growth forests. A few seedlings and juveniles of G. sub bullata have only been observed in the interior of forests, but never in nearby deforested areas. Based on these field observations, we conclude that the seeds of this species have low tolerance for forest disturbance, and therefore, are not able to germinate in open areas. In addition, because populations of G. subbullata are restricted to forested hills and low moun tains surrounded by cattle pastures and agricultural fields, their habitat is threatened by continuous selective logging, deforesta tion, and agricultural expansion. Thus, we suggest that Grias subbullata be assigned the IUCN conservation status of endan gered, EN Blab(iii) (IUCN, 2001).