Genlisea multiflora A.Fleischm. & S.M.Costa, 2017

Fleischmann, Andreas, Costa, Suzana M., Bittrich, Volker, Amaral, Maria Do Carmo Estanislau Do & Hopkins, Michael, 2017, A new species of corkscrew plant (Genlisea, Lentibulariaceae) from the Amazon lowlands of Brazil, including a key to all species occurring north of the Amazon River, Phytotaxa 319 (3), pp. 289-297 : 290-294

Genlisea multiflora A.Fleischm. & S.M.Costa , sp. nov. ( Figs. 1–2 )

Similar to Genlisea sanariapoana Steyerm. regarding scape indumentum and similar to G. guianensis N.E.Br. regarding capsule indumentum, but differs from both species by whitish to pale lilac corolla (5.5) 7–8.5 mm long including the spur (dark blueish-lilac corolla 15–16 mm long in G. sanariapoana and 10–18 mm long in G. guianensis ), and inflorescence a multiple-branched raceme at the peak of anthesis (simple racemes or rarely a double raceme).

Type:— BRAZIL. Roraima: Caracaraí, Viruá National Park, at “Estrada Perdida”, 59 m, 1 February 2017, S. M. Costa 1299 (holotype UEC!, isotypes INPA!, M!, RB!).

Perennial herb, 10–35 cm tall, leaves rosulate, heterophyllous. Laminar leaves not observed. Rhizophylls numerous, dimorphic: surface traps ca. 65 mm long, the trap stalk up to 30 mm long, trap arms up to 3 mm long, up to 1.3 mm wide, with 10–15 windings, neck 13–15 mm long and 0.6–0.8 mm in diameter, vesicle to 3 mm long and up to 1.2 mm wide; deep-soil traps similar, but more thin and filiform, 30–40 mm long, trap arms 10–15 mm long, up to 0.5 mm wide, neck ca. 5 mm long and up to 0.3 mm in diameter, narrowing towards the vesicle, vesicle up to 1.2 mm long and up to 0.6 mm wide. Inflorescence a simple raceme or multiple-branched raceme, with 10–37(–50) flowers; peduncle upper part, pedicels and calyx densely covered with indumentum of long-stalked glandular capitate hairs on septate stalks 0.3–0.4 mm long and slightly shorter eglandular hairs (0.1–0.2 mm long); peduncle (70–) 210–350 mm long, erect (but sometimes becoming prostrate when submerged), terete, diameter up to 3 mm near the base, strongly glandular in the upper part, base glabrous to sparsely glandular, the very base with simple eglandular hairs, lower part of the peduncle with up to 32 sterile bracts (“scales”); inflorescence ramifying and branching from bracts, ramifications of first order with several sterile bracts in their basal part; sterile bracts (scales) similar to flower-subtending bracts, but larger, densely covered with patent eglandular hairs when young or at inflorescence ramifications, older bracts at the peduncle base glabrous, frequently caducous; fertile bracts ovate, 1–1.5(–2.5) mm long and up to 0.8 mm wide, with acute apex and slightly gibbous base, densely covered with patent eglandular hairs, occasionally single glandular hairs; bracteoles narrowly lanceolate, 0.8–1.0(–2.0) mm long and up to 0.4 mm wide, with acute apex, covered with eglandular hairs. Pedicels terete, ca. 0.3 mm in diameter, up to 10 mm long during anthesis, up to 17 mm long in fruit, erect at anthesis and in fruit, densely covered with long-stalked glandular hairs and shorter eglandular hairs. Sepals subequal, lanceolate to narrowly lanceolate, acute, up to 1.2 mm long and up to 0.5 mm wide, densely covered with long-stalked glandular hairs and eglandular hairs. Corolla (5.5–) 7–8.5 mm long (including the spur), white or tinged pale lilac, with a yellowish mark at the base of the gibbous palate; upper lip entire, transversely elliptic to obovate, with apex rounded, irregularly crenulate to undulate, plain or lateral margins slightly reflexed, up to 3.5 mm long and 3.5–5.5 mm wide; lower lip shallowly trilobate, transversely elliptic in outline, up to 3 mm long and 3–5.5 mm wide, with gibbous palate; spur up to 5 mm long, much exceeding the lower corolla lip in length, straight and paralleling the lower corolla lip, cylindric-conical from widened base (2–2.5 mm in diameter), at the middle ca. 1.5–2 mm wide and abruptly narrowed to a conical tip 0.5–1 mm wide with obtuse apex; spur sparsely covered with short glandular (and sometimes eglandular) hairs. Capsule subglobose, ca. 2.5 mm in diameter, covered with very short, hispid eglandular hairs up to 0.1 mm long in the upper half (lower half subglabrous), capsule dehiscence circumscissile. Seeds 5-angularpyramidal to angulate-ovoid, very narrowly winged on the angles, light brown, 220–250(–280) μm long, 180–200 μm wide, testa with fine reticulation, the testa cells more or less isodiametric, with the anticlinal walls shallowly raised, and the periclinal walls tabular to slightly concave.

Distribution and habitat:—Thus far only known from two collection sites within the same range from Viruá National Park, Roraima state, Brazil. Given the vast, unexplored area of Amazon lowland floodplains (also in adjacent Venezuela and the Guianas) covered by white-sand savannas (“ campinaranas ”) and the increasing attention to this kind of vegetation, further records of this species seem likely in the near future. The species occurs at the grassarboreal white-sand savanna physiognomy, at the margins of lentic water bodies. The plants occur on hydromorphic soil that, though sandy, had fine granularity and some organic matter. This Genlisea species thus far apparently has been overlooked, as it grows seasonally inundated and hence it may not flower every year.

Etymology:—The species epithet ‘ multiflora ’ denotes the highly branched floriferous inflorescences of this species, with up to 50 or more individual flowers per scape.

Conservation Status:—Data Deficient (DD) according to IUCN (2012). It is quite probable that further populations of this species will be discovered within the range of the protected area of Viruá National Park. However, the two currently known populations along the “Estrada Perdida” are outside the national park, about 2 km from its nearest borders. The type location is in an area that suffers from anthropogenic impact, e.g. by trampling and fire. The population 2 km to the south of the locus classicus, also at a roadside of the Estrada Perdida, was hit by a large anthropogenic fire in 2016 (Beatriz Lisboa, park staff, pers. comm.) and no individual could be found at that site despite intensive search in 2017. The white-sand savannas throughout the Amazon are subject to massive anthropogenic impact (such as hydroelectric dams, mining, and illegal sand extraction), which change the environmental characters and reduce the local biodiversity, even leading to extinction of taxa ( Adeney et al. 2009, Adeney et al. 2016). Not even officially protected areas, such as the Viruá National Park, can totally prevent some deleterious impacts, especially in localities close to main access roads ( Adeney et al. 2009), as is the locus classicus of Genlisea multiflora .

Phenology and Ecology:—Collected in flower and fruit in January and February. Foliar leaves of G. multiflora were not present at any of the specimens studied, yet it remains without question that this species of Genlisea bears green foliar leaves like all members of the genus do, but probably not so much in flowering and fruiting specimens. Some species of Genlisea occasionally have very few to almost no foliar leaves present during anthesis and when in fruit (e.g. the related G. guianensis , see Figure 451 in Fleischmann 2012). This is occasionally the case in the more distantly related species Genlisea tuberosa Rivadavia et al. (2013: 464) , and regularly observed in G. oligophylla Rivadavia & A.Fleischm. in Fleischmann et al. (2011: 10) and G. uncinata Taylor & Fromm-Trinta (1983: 365) . In the latter two large species, the scape is becoming the main organ of photosynthesis during anthesis, and foliar leaves are much reduced ( Fleischmann et al. 2011). This could also be the case in the proportionally large scapes of G. multiflora , especially as the plants grow inundated under water for most of the year and seem to flower only during times of low water levels. When their habitats become exposed, it might be that the aquatic foliar leaves will desiccate easily and will decay–in case they are thin and membranous as in the related, likewise aquatic species G. guianensis and G. sanariapoana .

Taxonomic relationships:— Genlisea multiflora belongs to Genlisea section Genlisea of G. subgenus Genlisea , as can be evidenced from its seed capsules, which are of circumscissile dehiscence and which are held upright in fruit ( Fleischmann et al. 2010, Fleischmann 2012). Out of all members of that Neotropical section, it seems to be most closely related to Genlisea sanariapoana , based on corolla morphology and the dense scape indumentum, which consists of glandular capitate and eglandular hairs in both species. From that large species of the lower Orinoco region of Venezuela and Colombia, G. multiflora differs by its much smaller habit, a notably smaller corolla, and different capsule indumentum and seed shape. The closely related G. guianensis from the Guiana Shield uplands, Central-Eastern Brazil and Bolivia is geographically closer, and shares with G. multiflora a similar shape of the corolla lower lip, a capsule indumentum of short hispid eglandular hairs and narrowly winged angulate-pyramidal seeds, but G. guianensis has a very different scape indumentum (glabrous except hispid bracts, bracteoles, and calyx). Genlisea multiflora , G. guianensis and G. sanariapoana share a similar seed shape of angulate-ovoid to angulate pyramidal seeds with slightly raised wings on the angles and finely reticulate testa ( Fleischmann 2012). This seed shape is also observed in the phylogenetically close G. aurea and in G. roraimensis , while all derived members of G. section Genlisea have notably smaller, wing-less seeds with smooth testa ( Fleischmann et al. 2010, Fleischmann 2012). Genlisea multiflora , G. sanariapoana , G. guianensis and the closely related G. glabra (an endemic to the tepuis of the Guiana Shield) are unique among New World members of G. section Genlisea in having lilac to whitish flowers with a distinctive bicolored palate base (a feature paralleled in African Genlisea species), while all other members of that section have uniformly yellow flowers (rarely very pale yellow fading almost white). The close affinity of the Amazonian G. multiflora to the Guiana Shield members of G. section Genlisea is not surprising, and indeed a large percentage of plants occurring in Amazonian white-sand savannas show close floristic connections to oligotrophic habitats of the Guiana Shield ( García-Villacorta et al. 2016). At first glance, Genlisea multiflora resembles the three members of African G. section Recurvatae Fleischmann, Müller, Barthlott & Fischer (2010: 781) , most notably G. glandulosissima Fries (1916: 301) and G. pallida Fromm-Trinta & Taylor (1985: 177) , in terms of overall habit, the dense glandular scape indumentum and especially corolla morphology (spur much exceeding the comparatively short, convex and distinctly trilobate corolla lower lip; corolla lower lip with flat expanded part shorter than/equaling the gibbous, bicolored palate; corolla upper lip subequalling the lower lip in size). However, this similarity is merely superficial, as G. multiflora morphologically (and phylogenetically; Fleischmann, unpubl. data) belongs to the entirely Neotropical G. section Genlisea , as can be evidenced from seed morphology (it does not share the characteristic obovoid to globose seeds with isodiametrically reticulate testa ornamentation with distinctly raised anticlines, as found in all members of G. sect. Recurvatae ) and fruiting pattern (fruiting pedicels always reflexed in G. sect. Recurvatae ; Fleischmann et al. 2010, Fleischmann 2012).

Additional specimens examined (paratypes):— BRAZIL. Roraima: Caracaraí, Viruá National Park, Estrada perdida, depois do primeiro Boieiro, campinarana aberta sazonalmente inundada (atualmente não inundada, mas úmida), 27 January 2015, S. R. Chavez 70 (INPA! IAN!, K!, M!, MIRR!, MG!, MO!, NY!, P!, R!, SPF!, UEC!, UFRR!).

Figures

FIGURE 1. Genlisea multiflora. A. habit. B. indumentum of peduncle upper part. C. bract (left) and one bracteole (right) attached to peduncle and pedicel. D. indumentum of pedicel. E. calyx. F. corolla. G. capsule. H. seed. A, B from S.M. Costa 1299, C–H from S. R. Chavez 70. Drawing by A. Fleischmann.

FIGURE 2. Genlisea multiflora. A. habitat. B. habit of a plant with prostrate scape. C, D. corollae, face view (tinged pale lilac and white specimens). E. highly branched infructescence. F. corolla, lateral view. G. scape indumentum of a flowering specimen. H. fruits. J. SEM image of seed, base view (micropylar end). K. SEM image of seed, top (chalazal) view. Photos B–E, G, H by Volker Bittrich, rest by Suzana Costa.