Botanical novelties from Sierra de Maigualida , southern Venezuela . II

Grande, J.R., Kallunki, J., Arbo, M.M., Berry, P.E., Huber, O. & Riina, R. 2012. Botanical novelties from Sierra de Maigualida, southern Vene zuela. II. Anales Jard. Bot. Madrid 69(1): 7-19. Four new species, Siphocampylus acanthidiotrichus J.R. Grande (Campanulaceae), Phyllanthus huberi Riina & P.E. Berry (Phyllanthaceae), Sohnreyia maigualidensis J.R. Grande & Kallunki (Rutaceae), and Turnera maigualidensis J.R. Grande & Arbo (Turneraceae) are described and illustrated from the summit areas of Sierra de Maigualida in the Gua yana Highlands of southern Venezuela. To date, one genus, 32 spe cies, one subspecies, and one variety of angiosperms are known only from the Maigualida meadows and shrublands, between 1800 m and the highest elevation areas at 2400 m. Here we describe the first iteroparous species for the genus Sohnreyia K. Krause, a Turnera L. species with apically villose, apiculate petals, and a Siphocampylus Pohl species with aculeiform hairs and pinnatisect leaves. The new species, Siphocampylus acanthidiotrichus, together with S. tillettii Steyerm., represents a morphologically distinct subgroup within the genus.


INTRODUCTION
This is the second installment of a series of papers updating the floristic knowledge of Sierra de Maigualida, a relatively recently discovered granitic mountain range in southern Venezuela which is sorrounded by several typical Guayanan sandstone table mountains (tepuis).A description of the geography, geology and vegetation of this mountain range, including a detailed map, can be found in Huber & al. (1997) and in the first issue of this series (Nozawa & al., 2010).A preliminary checklist of the vascular plant species of the Sierra de Maigualida is given in Rodríguez & al. (2008), but a more detailed one, including floristic patterns, as well as the history of its botanical exploration, is in preparation (Grande & al., in prep.).
In the present contribution, four species belonging to four families (Campanulaceae, Phyllanthaceae, Rutaceae and Turneraceae), are described and illustrated.Some of them exhibit remarkable features within their respective genera.This is the first record of an iteroparous species for the genus Sohnreyia (Rutaceae), a Turnera species with apically villose, apiculate petals, and a Siphocampylus species with aculeiform hairs and pinnatisect leaves.
The continuous exploration work and new cartography generated require some corrections on the topographical nomenclature in this region.Localities referring to "Río Chajura" in previously published species [including those in Botanical Novelties from Sierra de Maigualida, southern Venzuela.I (Nozawa & al., 2010)] are to be changed to Río Yudi, according to the updated geographical information included in Huber (1995), and cited in Huber & al. (1997).

CAMPANULACEAE
The following new species was treated as Siphocampylus sp.A in Flora of the Venezuelan Guayana (Stein, 1998), in which a brief description as well as an illustration.It was not accounted accounted for, however, in the Nuevo Catálogo de la Flora Vascular de Venezuela (Madriz, 2008).Siphocampylus acanthidiotrichus J.R. Grande, sp.nov.

Diagnostic characters
Siphocampylus acanthidiotrichus is the only known species in the genus with tiny aculeiform trichomes.It is very similar to S. tillettii Steyerm., from which it can be differentiated according to the characters listed in Table 1.Although infrageneric, and even generic divisions within subfamily Lobelioideae do not reflect the current phylogenetic hypothesis (Knox & al., 2008;Lammers, 1998), until now the most thorough classification is that of Wimmer (1953), according to which Siphocampylus acanthidiotrichus and S. tillettii are part of Siphocampylus sect.Macrosiphon subsect.Eusiphocampylus (A.DC.) E. Wimm.Both species can be assigned to this subsection by virtue of their corolla tubes, which are 2-5 times longer than the limb, and their filaments, which are adnate to the corolla from the base to the constriction.By virtue of their habit (geniculate, rooting at lower nodes and not exceeding 0.5 m high), surface of leaves and stems (bullate), texture and margins of leaves (coriaceous), relatively long pedicels, and corolla with reddish-orange tube and yellow lobes, they could be considered part of a small, well-delimited group restricted to the Guayana Highlands.

Distribution and habitat
Siphocampylus acanthidiotrichus is endemic to Sierra de Maigualida, where it grows in shrubby meadows at 2100-2150 m elevation, on soils developed from granitic substrate.According to the information in the collection labels it is not clear whether S. acanthidiotrichus grows on peatlands or on rocky exposures.Siphocampylus tillettii, the most similar species, is restricted to rock outcrops on Cerro Marahuaka (Stein, 1998;Steyermark, 1978), a sandstone table mountain in western Venezuelan Guayana.

Etymology
The species honors our friend and colleague Otto Huber, a dedicated worker on the flora and vegetation of the Guayana Region, and the first person to botanically explore the high ridges of Sierra de Maigualida.

Diagnostic characters
The only other species of Phyllanthus known to date from the higher altitudes of the Sierra de Maigualida is P. obfalcatus Lasser & Maguire.That species differs, however, in its more numerous leaves on the side branches (> 40), its narrower and more falcate leaf blades (1-2 mm wide), and in having a distinct subapical gland 0.1-0.2mm diam.on the lower leaf surface.Following Webster's key to Phyllanthus in the Flora of the Venezuelan Guayana (Webster, 1999), P. huberi keys out closest to P. maguirei Jabl.and P. tepuicola Steyerm., both high elevation species to which it is presumably allied phylogenetically and characterized by the lack of laminar glands, bifid styles, muticous/emarginate anthers, and the presence of six disk segments in both flower sexes.Of the two, P. huberi is more similar to P. tepuicola, which is endemic to Cerro Duida, to the southwest in Estado Amazonas.Phyllanthus huberi can be distinguished by its larger leaves with an emarginate apex, strongly revolute margins, longer petiole, and shorter pistillate pedicel.
Although Phyllanthus huberi is entirely glabrous, the stems and branchlets of the three specimens cited all have a notable blackish growth that could initially be confused with pubescence.This covering is most likely due to the presence of fungal hyphae, perhaps associated with the very humid and cool conditions at the high elevation shrublands and meadows in which the species occurs.Steyermark (1988) made reference to this same phenomenon in several species of Ilex L. (Aquifoliaceae) from the Guayana Highlands.

Distribution and habitat
This species is only known from the Sierra de Maigualida, in the Venezuelan Guayana Region, along the border of estado Bolívar and estado Amazonas.It occurs there on sandy soils along streams, at the edge of rock outcrops, and in herbaceous meadows, at 2100-2150 m elevation.

RUTACEAE
Sohnreyia K. Krause is a small genus with four species from the Amazonian-Guayanan region of northern South America (Appelhans & al., 2011).As presently understood it is a member of tribe Spathelieae, subfamily Spathelioideae, together with the related Spathelia L. and Dictyoloma A. Juss.Despite some early disagreement about its taxonomic placement and circumscription, this genus is currently accepted as a member of the family Rutaceae, order Sapindales (Stern & Brizicky, 1960;Chase & al., 1999;Groppo & al., 2008;Appelhans & al., 2011;Stevens, 2011).
So far, species described in Sohnreyia are characterized by its apically crowded paripinnate leaves, with 7-24 pairs of leaflets, phyllothyrsiform terminal inflorescences (inflorescence terminology following Austin, 1973), and fruits 2-3-winged, wider than long.They are monopodial and semelparous, a combination present also in some monocots like Agave L. (Agavaceae-Asparagaceae) and Corypha L.
(Arecaceae) but very rare in dicots (Janzen, 1976;Bell, 1980).León & Alaín (1951), in fact, reported that plants of the related Spathelia die six months after flowering, once the fruits have ripened.Collections made in the late 1980's and early 1990's above 2000 m elevation in the highlands of Sierra de Maigualida (Central Venezuelan Guayana), however, have revealed the existence of individuals similar to Sohnreyia ulei (Engl.ex Harms) Appelhans & Kessler that are capable of producing axillary inflorescences and show an itero parous condition, being monopodial or sometimes sympodial.These individuals, additionally, are relatively shorter and exhibit a very dense ferruginous pubescence on young organs and leaves with only 2-4(5) pairs of smaller, rugose leaflets (Kallunki, 2005).A deeper examination of the complete set of specimens revealed further differences in the type and distribution of the pubescence, as well as in the filaments, ovary, stigma, and fruit.All together, they suggest a substantial differentiation of the populations on granitic substrate at higher altitudes in Sierra de Maigualida from those that occur on sandstone within a wider altitudinal range, and convinced the authors that it merits specific recognition.Sohnreyia maigualidensis J.R. Grande & Kallunki, sp.nov.

Etymology
The specific epithet refers to the type locality.

Diagnostic characters
Since Linné (1760) established Spathelia sorbifolia L., 29 species and one variety in four different genera have been described in the tribe Spathelieae.Fourteen to twenty

TURNERACEAE
Although Turneraceae could be circumscribed within Passifloraceae as subfamily Turneroideae on the basis of molecular phylogenetic evidence (APG III, 2009;Stevens, 2011), in this contribution it is retained as a distinct family.Turnera maigualidensis J.R. Grande & Arbo, sp.nov.
The new species can be easily differentiated from all previously described taxa within Spathelia and Sohnreyia by its paucifoliolate leaves (only 2-5 pairs of leaflets vs. 7-24 pairs in the rest of the species), densely covered by a ferrugineous indumentum of mixed stellate and simple hairs and by its small inflorescences, both terminal and axillary (vs.exclusively terminal).

Distribution, habitat, and phenology
The new species seems to be restricted to small, open areas scattered in the highlands (1800-2200 m) of Sierra de Maigualida, located in the north-central part of the Guayana phytogeographic region and the Pantepui Pro vince (Huber & al., 1997).It is a mostly monopodial or rarely ramified shrub, with a very sparse crown, which grows in large colonies of numerous individuals that are usually separated several meters from each other.The average height is between 1-3 m, but shorter (juvenile) and taller individuals (up to 7 m) have also been observed, the latter especially on rocky substrates and in the ecotone zone with the low elfin forest.

Etymology
The specific epithet refers to the type locality.

Diagnostic characters
The new species differs from other described species of Turnera L. by the overlapping leaves, congested towards the apex, with revolute margins, a sole pair of cupuliform nectaries at the junction of the petiole, and petals with the apex apiculate and villose.Turnera maigualidensis belongs to series Salicifoliae Urb., which includes species having stipules small or rudimentary, upper leaf surface glabrous or subglabrous, solitary flowers, free flower pedicel, narrow prophylls, ovary glabrous and styles pilose.Upright long branches foliated only towards the apex, are present like in many specimens of T. glaziovii Urb. and T. rupestris, and in T. arcuata Urb.(series Turnera).Leaf base is somewhat prominent and stipules are persistent after leaf abscission as in T. cicatricosa Arbo, the pedicel is not developed, as in T. venosa Urb.The new species differs from all species in the series by presenting small imbricate leaves with revolute margins.The latter is a rare character in the genus, present in a few species of series Leiocarpae Urb. and series Sessilifoliae Arbo.

Distribution and habitat
According to the information from collection labels, this new species is a low shrub, fairly scarce in its natural habitat.It is only known from the type collection.

Fig. 1 .
Fig. 1.Siphocampylus acanthidiotrichus: a, habit, detail of adaxial surface of leaf blade; b, apex of the flower, with details of pubescence abaxial side of corolla lobe; c, calyx, with detail of pubescence at the apex of the calyx tube; d, seed, extended surface, showing the tiny foveae; e, antheral tube.(Drawn by Bruno Manara from O. Huber 12746 [holotype]: a, c, f, O. Huber & L. Izquierdo 12782; b, d, e, from O. Huber 13067).

Fig. 3 .
Fig. 3. Sohnreyia maigualidensis: a, habit, included are details of the pubescence of the adaxial and abaxial surfaces of the leaflets; b, stamen, internal side; c, apical portion of a ramification of a terminal inflorescence, showing one flower in anthesis; d, fruits.(Drawn by Bruno Manara; a-d from O. Huber 13063 (holotype), except the terminal inflorescence of a, from O. Huber 13097).

Fig. 5 .
Fig. 5. Turnera maigualidensis: a, flowering branch; b, leaf, abaxial side; c, portion of branch, showing the insertion of the leaves with pilose stipules, persistent after leaf abscission; d, flower with prophylls; e, floral pedicel and prophylls with stipules; f, outer portion of the calyx, showing indumentum of inner and outer lobe; g, apex of an outer lobe; h, apex of an inner lobe; i, calyx tube portion, inside, with two petals and one stamen adnate, the scars of two stamens have been squared; j, apical portion of a petal; k, anther, dorsal view; l, anther, ventral view; m, longistylous gynoecium.(Figs.a, d, Bruno Manara; figs.b, e-m, Liliana Gómez; all figures from the type specimen).