Vochysia condorensis Huamantupa & D. A. Neill, 2018

Huamantupa-Chuquimaco, Isau & Neill, David A., 2018, Vochysia condorensis (Vochysiaceae), a new species from the Cordillera del Cóndor, Ecuador, Phytotaxa 340 (1), pp. 79-85 : 80-83

Vochysia condorensis Huamantupa & D. A. Neill , sp. nov. ( Figures 1–3 .)

Type: — ECUADOR. Morona-Santiago: Cantón Limón Indanza, Cordillera del Cóndor, Centro Shuar Yunkumas, Cerro Chuank Naint (“Vulture Mountain” in Shuar), sandstone plateau, dense wet forest, near 1-ha forest inventory plot, 1150 m, 03º03’34”S, 78º14’45”W, 17 September 2005, D. Neill & NSF dendrology course students 14603 (Holotype: QCNE 193639!, Isotypes: AAU, CUZ!, ECUAMZ, HUT, K, LOJA, MO!, NY!, US).

Diagnosis: — Vochysia condorensis is characterized by being a small to medium tree, 4–20 m, pachycaul, with candelabriform architecture, leaves glabrous, obovate, oblong to spathulate, 9.5–30 × 5.9–13.5 cm, with the inflorescence erect and solitary, axis fistulose, and the cincinni with 2 to 3 flowers.

Tree 4–20 m, trunk up to 60 cm in diameter, pachycaul, with candelabriform architecture, sparsely branched, the branches curved upward, young branchlets terete, subangulate or subcylindric, finely cristate, drying darkish red, mostly glabrescent, but tomentulose mostly toward the apices, with a gummy exudate when cut that turns red upon drying; stipules triangular, ca. 1 mm long. Leaves clustered distally on the branches; in verticils of 4 to 8; petiole 1.2–2.3 cm, subcylindric, sulcate-channeled adaxially and striate abaxially; lamina of leaf relatively thick and coriaceous, obovate, oblong, or spathulate, 11–30 × 5.9–13.5 cm; apex rounded, retuse; base acute, cuneate, clearly decurrent on the petiole; margin entire, revolute, especially in the distal half; glabrescent on both sides, with very sparse, scattered, simple hairs ± 0.7 mm long; midvein impressed adaxially, prominent abaxially, up to 4 mm wide; venation reticulate-pinnate, the secondary veins in 16–26 pairs, spaced 0.5–1.7 cm apart, and forming an angle of 70–80° with the midvein, impressed adaxially, markedly prominent abaxially, frequently with a single lateral collector vein; venules abundant; the marginal vein, 0.3–0.5 mm from the margin, sub-impressed adaxially and prominulous abaxially. Inflorescence terminal, erect, 10–30 cm long; axis of the inflorescence frequently fistulose; cincinni 2–3-flowered, the floral axis densely pilose-ferrugineous. Buds elongate, 1.6–2.5 cm long, densely pilose-tomentose; peduncles of the cincinni 1.8–3.4 cm long; pedicels 5–17 × 0.6–1.4 mm long, densely pilose-tomentose. Flowers yellow-orange. Spurred sepal 2.1–3.5 cm long; spur slightly recurved, apex obtuse to rounded, 7–12 mm long and 1.2–2 mm wide towards the base, forming an angle of 40–60° with the pedicel; dorsal sepal ± 3 cm long not including the spur, sparsely pilose-ferrugineous; smaller sepals less than 3 mm long. Petals 3, unequal, oblanceolate to acute, sparsely ciliate on the midvein with a few scattered malpighian hairs; the central petal more developed, 14–21 × 4–5 mm, the laterals 10–14 × 2.5–4 mm; the central petal not exceeding 2/3 the length of the developed dorsal sepal. Stamen 1, 2.5–3.1 cm long, with a few scattered hairs at the margins on the back of the filament, slightly curved, the filament short, 0.8–1.2 mm long; anthers 2.5–3.1 cm long, with a few scattered hairs at the margins, conduplicate, navicular, each exposed theca ca. 1.2 mm wide. Staminodes 2, glabrous, deltoid-sagittate, 1.5–2.2 mm long. Ovary trilocular, ± 1.5 × 2.0 mm, glabrous. Style ± 3 cm long; stigma subterminal, capitate-triangular, glabrous. Fruit a verruculose woody capsule, ellipsoid, 3.5–5.2 × 1.5–2.7 cm.

Ecology and Distribution: — Vochysia condorensis is currently known only from the Ecuadorean portion of the Cordillera del Cóndor, in the provinces of Morona-Santiago and Zamora-Chinchipe, between 1150 and 1640 m elevation. In this region the species occurs in forests on sandstone plateaus of the Hollín Formation, on nutrient-poor sandy soils, and on the slopes below these plateaus, on sandy soils eroded from the plateaus. The species associated with V. condorensis in these low-statured forests include some elements that also occur on sandstone tepuis in the Guiana Shield, such as Digomphia densicoma (Martius ex de Candolle 1845: 232) Pilger (1910: 371) , Bonnetia paniculata Spruce ex Bentham (1861: 63) and Retiniphyllum tepuiense Steyermark (1965: 237) . Other species that occur in these forests with V. condorensis are distributed on sandstone formations to the south in Peru, such as Schefflera harmsii Macbride (1959: 31) and Pagamea dudleyi Steyermark (1975: 226) . In the Cordillera del Cóndor, V. condorensis has not been found on other geological formations besides the Hollín sandstones, such as the granitic Zamora batholith or the Napo Formation limestone.

Given that some records of V. condorensis are located a few kilometers from the Ecuador-Peru border, it is likely that the species occurs on the Peruvian side of the Cordillera del Cóndor, in the Amazonas Region.

Phenology: — Vochysia condorensis flowers from March to October and fruits in March, but probably to December.

Conservation status: —Populations of Vochysia condorensis are relatively small and isolated, due to the patchy distribution of the sandstone plateaus which are its exclusive habitat. This species has been recorded in the Cerro Plateado Biological Reserve, the largest formally protected area in the Ecuadorian portion of the Cordillera del Cóndor, covering 26,000 hectares in southern Nangaritza canton, Zamora-Chinchipe. It also occurs in several smaller community reserves owned and managed by indigenous Shuar communities in Morona-Santiago, in the northern portion of the species range. In other areas of the Cordillera del Cóndor region, native forests are being disturbed by mining operations. While mining is typically not carried out on the sandstone formations where the species occurs, its habitat may be affected in the future by mining impacts and other drivers of deforestation. In the Fruta del Norte mining concession in Yantzaza canton, Zamora-Chinchipe, the mining company Lundin Gold, Inc., is taking steps to mitigate the environmental impacts of its operations, including a program of conservation in situ and ex situ of V. condorensis and other locally endemic plant species.

Based on the criteria of the IUCN (2017), the geographic distribution of the species was calculated with Geocat Software (2017); the extent of occurrence of V. condorensis is 2,258 km ² and the area of occupancy is 32 km ², with the result that this species is classified as Endangered (EN).

Etymology: —The species name is derived from the Cordillera del Cóndor mountain range, which comprises its entire known distribution.

Paratypes: — ECUADOR, Morona-Santiago: Cantón Limón Indanza, Cordillera del Cóndor , 03°07’S, 078°14’W, 1500 m, 22 July 1976 (fl.), G. Argent & R. B. Burbidge 268 ( MO!) ; Cumbre del Cerro Chikichiki Naint a 4 km SE del Centro Shuar Warints , 03°10’13”S, 78°14’ 33”W, 1220 m, 9 October 2002 (fl.), G. Toasa 8950 ( MO!, QCNE!) ; Centro Shuar Yunkumas, Cresta del Cerro Chuank Naint, roca arenisca blanca, 03°03’39”S, 78°14’24”W, 1200 m, 4 September 2005 (fl.), C. Kajekai et al. 205 ( MO, QCNE!). Zamora-Chinchipe: Cantón Nangaritza, Cordillera del Cóndor , Parroquia Zurmi , comunidad Yawi , cima de la cordillera, 04°29’59”S, 78°38’18”W, 1600 m, 15 June 2005 (fl.), W. Quizhpe et al. 1442 (LOJA!, MO!) ; Reserva Biológica Cerro Plateado, dense low forest on Hollín Formation sandstone slope above Río Numpatakaime , 04°35’28”S, 78°50’55”W, 1620 m, 19 August 2012 (fl.), D. Neill, M. Asanza & E. Cueva 17401 ( ECUAMZ!) ; Cantón Yantzaza, Cordillera del Cóndor, carretera desde Los Encuentros hacia el Cerro Machinaza , sendero a Las Peñas , 03°47’15”S, 78°29’48”W, 1440 m, 18 July 2005 (fl.), W. Quizhpe 1602 (LOJA!, MO!) ; Cuenca del Río Machinaza, Campamento las Peñas , tercera parcela, 03°46’S, 78°29’W, 1500 m, 19 September 2009 (fl), W. Quizhpe et al. 3107 (LOJA!, MO!) ; 1 km N of Río Machinaza hacia Las Peñas, ridgetop, Fruta del Norte mining concession of Kinross Aurelian gold mine company, 03°46’33”S, 78°29’46”W, 1640 m, 20 March 2008 (fl.), D. Neill & W. Quizhpe 16272 ( CUZ, MO!, QCNE!) ; 20 March 2008 (fr.), D. Neill & W. Quizhpe 16273 ( MO, QCNE!) ; 03°46’36”S, 078°29’43”W, 1620 m, 28 June 2009 (fl.), D. Neill & C. Kakejai 16607 (LOJA, MO) ; 03°46’33”S, 078°30’07”W, 1620 m, 4 July 2009 (fl.); D. Neill & C. Kakejai 16635 ( ECUAMZ!, LOJA!, MO!) .

Discussion: —According to the infra-generic classification proposed for Vochysia by Stafleu (1948), Vochysia condorensis is placed in Vochysia sect. Ciliantha Stafleu (1948: 445) , subsect. Megalanthae Stafleu (1948: 484). Vochysia section Ciliantha has the following characteristics: bark rarely exfoliating; stipules always present, rarely less than 4 mm long; leaves opposite to verticillate; venation reticulate; petals 3, rarely 1; petals and (or) stamen ciliate along the margins, sometimes pilose on the back; style and ovary glabrous. Vochysia subsection Megalanthae is characterized by: bark not exfoliating; leaves in verticils of 4 or more, glabrous; inflorescence terminal and sparsely pilose; flower buds spurred, 1.5–3.5 cm long, the spur never longer than the fourth sepal; petals 3; anther pilose on both sides or on one side only, filament very short, 0.1–0.15 cm long; staminodia developed, glabrous; stigma capitate. Vochysia condorensis shares some characteristics with Vochysia duquei Pilger (1937: 498) and Vochysia gigantea Stafleu (1948: 489) , which are placed in the same subsection; the three species are distinguished in Table 1.

Also V. condorensis has a candelabrum-like architecture, pachycaul with a few thick branches that bend upwards and relatively large, thick, coriaceous leaves clustered distally on the branches. This architecture is similar to some species of small shrubby trees in the Brazilian Cerrado in Vochysia sect. Vochysiella Stafleu (1948: 424) subsect. Decorticantes ( Warming 1875: 57) Stafleu (1948: 425) , and particularly to Vochysia rufa Martius (1826: 144) , a common species in cerrado vegetation. However, differences in vegetative features and floral structure, including the surface of the leaf densely rufous-ferrugineous, tomentellous, axis of the inflorescence densely ferrugineous tomentose, and cincinni with 2-4 flowers, indicate that V. condorensis does not have strong affinities to this mostly Brazilian group of Vochysia . No other species of Vochysia in Ecuador or Peru has the candelabrum-like architecture of V. condorensis , based on our field experience. Another striking characteristic of V. condorensis is a rather thick exudate in the bark that dries dark red; this is reflected in herbarium specimens, which have red leaves and dark reddish branches. An additional characteristic feature is the presence of a few scattered hairs at the margins on the back of the filament of stamens.

Figures

FIGURE 1. Vochysia condorensis. A. Flowering branch - D. Neill et al. 14603 (QCNE, holotype). B. Flowering branch (photo, D. Neill, from the type locality). C. Fruits - D. Neill & W. Quizhpe 16273 (MO).

FIGURE 2. Illustration of Vochysia condorensis. A. Habit with inflorescence. B. Entire leaf and a close-up of the undersurface. C. Flower with pedicel. D. Calyx showing the staminodes (with arrow) and part of the ovary. E. Flower sectioned longitudinally, showing the arrangement of the carpels and style. F. Petals. G. Stamen. H. Thecae in transverse section. (Illustration by Alba Arbeláez based on the type, D. Neill et al. 14603).