Schiekia orinocensis (Kunth) Meisn., Pl. Vasc. Gen. 2(12): 300. 1842.

Pellegrini, Marco O. O., Hickman, Ellen J., Guttierrez, Jorge E., Smith, Rhian J. & Hopper, Stephen D., 2020, Revisiting the taxonomy of the Neotropical Haemodoraceae (Commelinales), PhytoKeys 169, pp. 1-59 : 1

4.1. Schiekia orinocensis (Kunth) Meisn., Pl. Vasc. Gen. 2(12): 300. 1842. Fig. 13

Wachendorfia orinocensis Kunth, Nov. Gen. Sp. (quarto ed.) 1(3): 319. 1816. Lectotype (designated here). Venezuela. Isla de Pararuma, in humidis, in ripa Orinoco propter confluentem Sinaruci et in insula Pararuma, fl., fr., May, F.W.H.A. Humboldt & A.J.A. Bonpland 843 (P barcode P00669614!; isolectotype: P barcode P00669615!).

Xiphidium angustifolium Willd. ex Link, Jahrb. Gewächsk. 1(3): 73. 1820, nom. superfl., Syn nov.

Troschelia orinocensis (Kunth) Klotzsch & M.R.Schomb., Reis. Br.-Guiana 1066, 1120. 1849.

Schiekia flavescens Maury, J. Bot. (Morot) 3: 269. 1889. Lectotype (designated here). Venezuela. Upper Río Orinoco, Atures, Salvajito, fl., 3 Apr 1887, M. Gaillard 52 (P barcode P06891121!, pro parte, the two specimens on the sides).

Schiekia congesta Maury, J. Bot. (Morot) 3: 269, f. 12. 1889, nom. nud.

Schiekia orinocensis subsp. savannarum Maguire & Wurdack, Mem. New York Bot. Gard. 9(3): 320. 1957. Holotype. Venezuela. Amazonas: Cerro Yapacana, Río Orinoco, in savannah no. 1, northwest base of the mountain, fl., fr., 31 Dec 1950, B. Maguire et al. 30496 (NY barcode 00214486!; isotypes: F barcode V0045884F!, K barcode K000574294!).

Nomenclatural notes.

When describing Wachendorfia orinocensis , Kunth (1816) mentions a collection made on Isla de Pararuma, Río Orinoco, but makes no reference to the collector, collection number, or herbarium. During a visit to P herbarium, we came across two specimens in which the labels matched the locality in the protologue and also had a label indicating it had been part of the Bonpland & Humboldt herbarium. The specimen P00669614 is clearly what the majority of the original illustration was based upon, while P00669615 was only used to illustrate the fruits. Thus, since the specimen P00669614 possesses well-preserved leaves and stems, floral buds, and mature flowers, it is here designated as the lectotype.

When describing Schiekia flavescens , Maury (1889) mentions two collections, Gaillard 52 and Chaffanjon 185. During a visit to P, we were unable to locate the collection Chaffanjon 185 but managed to find Gaillard 52. The latter was cited by Maury as a mixed gathering, with two specimens of his S. flavescens and a central specimen of S. orinocensis . Thus, we designate the two lateral specimens (right and left) as comprising the lectotype for S. flavescens .

Distribution and habitat.

Schiekia orinocensis , in its current circumscription, is a far more geographically-restricted taxon than traditionally accepted. It is known to occur in Colombia, Guyana, Venezuela, and Brazil (States of Amazonas, Pará, and Roraima) (Fig. 14 ), in tepuis and other montane formations in the Guyana Shield, in seasonally-flooded environments.

Phenology.

It was found in flower and fruit from June to October, during the dry season.

Conservation status.

Schiekia orinocensis possesses a wide EOO (1,193,173 km2) but a relatively narrow AOO (ca. 224 km2). This narrow AOO might be related to the relatively reduced number of collections, especially when compared to S. timida . The relatively small number of specimens might be due to the difficulty of reaching and collecting in tepuis and other mountainous formations in the Amazon Region. Nonetheless, field observations by one of us (EJH) indicate that S. orinocensis forms considerably smaller and more restricted subpopulations than S. timida , which might indicate it is ecologically more specific in its requirements. Thus, following IUCN’s (2001) recommendations, S. orinocensis should be considered as Vulnerable [VU, A2ab+C2a(i)].

Comments.

Schiekia has consistently been treated as a monospecific genus until the present study, given that S. flavescens has been considered a synonym of S. orinocensis since very early days. Nonetheless, previous studies, such as Maguire and Wurdack (1957) and Maas and Maas-van de Kamer (1993), have treated the polymorphism observed in herbarium specimens by recognising different subspecies. Both previous attempts to divide S. orinocensis were almost entirely based on vegetative morphology ( Maguire and Wurdack 1957; Maas and Maas-van de Kamer 1993), with the second one also relying on the proportion between the leaves and the inflorescences ( Maas and Maas-van de Kamer 1993). The observed variation in plant stature and leaf length and width, which was used by previous authors to recognise subspecies ( Maguire and Wurdack 1957; Maas and Maas-van de Kamer 1993), seems to be environmental and, thus, is here disregarded as taxonomically relevant. Our present treatment is based on extensive field and herbarium studies. It suggests that three species can be recognised based on ecological preferences, rhizome morphology, leaf morphology, tepal arrangement and colouration, the width of the filiform staminode-like projections, capsules morphology and colouration, and seed ornamentation. Schiekia orinocensis s.str. is morphologically similar to S. timida due to its rhizome morphology, leaf arrangement and consistency, inflorescence architecture, upright to patent flowers, inflated medial filament, and tuberculate seeds. Schiekia orinocensis s.str. can be differentiated by its leaves with inconspicuous veins (vs. conspicuously veined in S. timida ), chasmogamous and bilabiate flowers (vs. cleistogamous and narrowly tubular), pedicels gibbose at the apex (vs. not gibbous), tepals with apex reflexed and apricot to cream (vs. straight and light to medium green), upper tepals with three dark orange to orange-brown nectar guides (vs. lacking nectar guides), staminode-like projections fusiform and almost as long as its subtending tepal (vs. filiform and 1/3 the length of its subtending tepals) and capsules broader than long (vs. slightly longer than broad or as broad as long). Schiekia orinocensis s.str. and S. silvestris share the chasmogamous flowers and upper tepals with nectar guides, thick and fusiform staminode-like projections and capsules slightly longer than broad or as broad as long. Nonetheless, they can be easily differentiated based on vegetative morphology, flower orientation, inflation of the medial filament, capsule colouration, and seed ornamentation (see below).

Figures

Figure 13. Schiekia orinocensis (Kunth) Meisn A habitat B habit, showing an inflorescence from this flowering season and an old one from the previous year bearing dehisced capsules C root D leaf blade E inflorescence F, G flower: F side view of a flower showing the nectar drop (arrow) in the perianth aperture G frontal view of a flower H-L perianth segments: H upper perianth tepals showing their connate bases and the nectar guides I lower lateral tepal J side view of the lower lateral tepal showing the glandular pubescence K staminode-like projection L lower medial tepal M flower with perianth removed, showing the androecium and gynoecium. N, dehisced capsules. All photos by E. J. Hickman.

Figure 14. Distribution of Schiekia orinocensis (Kunth) Meisn. Beige - Temperate Coniferous Forests and Boreal Forests; Yellow - Temperate Grasslands, Savannahs and Shrublands; Pink - Temperate Broadleaf and Mixed Forests; Light Green - Subtropical Coniferous Forests; Red - Deserts, Xeric Shrublands and Tropical Coniferous Forests; Orange - Tropical / Subtropical Grasslands, Savannahs and Shrublands; Maroon - Dry Broadleaf Forests; Green - Moist Broadleaf Forests; Lilac - Montane Grasslands and Shrublands.