Psammisia pseudoverticillata Pedraza, 2015

Pedraza-Penalosa, Paola, 2015, New blueberry and mortino relatives (Ericaceae) from northwestern Colombia, PhytoKeys 49, pp. 33-58 : 37-39

Psammisia pseudoverticillata Pedraza sp. nov. Figures 4, 5, 6

Diagnosis.

Psammisia pseudoverticillata can be easily differentiated from all other Psammisia s.l. by its leaves, which are clustered and seemingly verticillate, chartaceous, large, obovate, bullate in vivo, pinnate, decurrent at the base, and subtended by a basally pulvinated petiole. Its congested racemes bear flowers that are distinctive because of their large size, thickness and fleshiness; however, it must be noted that the flowers of this new species shrink significantly upon drying. The flowers of Psammisia pseudoverticillata are also characterized by its color combination and angled calyces and corollas (calyces markedly angled).

Type.

COLOMBIA. Antioquia: Municipio Urrao. Corregimiento La Encarnación, Vereda Calles, Parque Nacional Natural Las Orquídeas, camino Calles-La Encarnación, después de la confluencia del Río Polo y el Río Calles, antes del Río San Pedro, sitio La Quiebra, 6°30'31"N; 76°14'W, 1600-1850 m, 31 Jan-2 Feb 2011 (fl), P. Pedraza-Peñalosa, J. Betancur, M. F. González, G. Giraldo, F. Gómez, A. Duque & J. Serna 2134 (holotype: COL!; isotypes: HUA!, NY! [NY02058402]).

Description.

Terrestrial shrubs with arching branches, <1 m tall; stems and twigs somehow flatten, caniculated lengthwise, apparently glabrous, the hairs inconspicuous (<0.1 mm long), unicellular and eglandular (= minute hair type), bark brown and smooth. Axillary buds not observed. Leaves alternate, originated very close together, pseudoverticillate with clusters of 3-5 leaves separated by leafless sections several centimeters long; petiole caniculate, basally pulvinate, 4-12 mm long, glabrate, minute type of hair; lamina chartaceous, bullate in vivo, obovate, (17.5-)20.5-24 × (6.5-)12-14.2 cm (at least 24 cm long, apices incomplete), base attenuate and decurrent, margin entire and eciliate, apex missing in herbarium specimens but probably acuminate, glabrate on both sides, adaxially with caducous minute hairs, abaxially the hairs of arachnoid type, ca. 1 mm long, very thin, multicellular and eglandular; laminar glands absent; venation pinnate, with up to 4 orders visible adaxially in dry specimens, midrib adaxially impressed and abaxially raised, at least 9-11 secondaries per side, these alternate or subopposite, evenly dispersed along the lamina, ascending, adaxially flat and abaxially raised, brochidodromous, intersecondaries frequent. Inflorescence an axillary, solitary, 6-8-flowered raceme; inflorescence bracts, floral bract, and bracteoles alike, persistent, chartaceous, cream-reddish-colored, ovate, 1.6-1.8 × 1.5-2 mm, margin entire and inconspicuously ciliolate, the hairs of the minute type but a few are multicellular, apex obtuse or acute, glabrous on both sides, venation obscure, the bracteoles are different in having apex acute and more abundant marginal multicellular hairs that are fused in masses of fimbria toward the base; peduncle 4 mm long, rachis 5-10 mm long, both red-brown, glabrate, the hairs of the arachnoid type, also covered with minute, whitish warts in vivo (inconspicuous when dried, though imparting rough look); pedicel red-brown, articulate with calyx, 12-14 mm long (17 mm in vivo), with the same indumentum and warts of the rachis; bracteoles 2, basal, supopposite to alternate. Flowers 5-merous, actinomorphic, diplostemonous. Calyx red-brown, ellipsoid, 5-angled, the angles sharp and opposite to the sinuses, 8-9.2 mm long (10.5-11 mm in vivo), sparsely tomentulose with a combination of arachnoid and minute hair types, specially warty distally; tube ellipsoid, 6-7.4 mm long (8.5-9 mm in vivo); limb erect, 1.8-2 mm long; lobes deltate, 1 × 3.2 mm long, (1.5-1.7 × 4 mm in vivo), margin scariose (except at apex) and sometimes broken up in segments or with a few multicellular and eglandular hairs, apex acute; sinuses obtuse (U-shaped); aestivation unknown. Corolla dark pink with white throat and lobes, very fleshy, not bistratose, urceolate, 5-angled, 12-14 mm long (19 mm in vivo), 4-5.2 mm diam. (ca. 10 mm in vivo), 2.4-3 mm wide at throat (ca. 5 mm in vivo), puberulous without with a combination of arachnoid and minute hairs, the indumentum more abundant distally, glabrous within; lobes ovate, ca. 1.1 × 1.1 mm (ca. 2 × 2 mm in vivo), apex acute, reflexed at maturity; aestivation valvate. Stamens 10, equal, 8.7-9 mm long, included, not adherent to corolla; filaments free, long-triangular, 2.3-2.5 mm long, marginally glabrate, with minute hairs; anthers 8.3-8.5 mm long, connective spurless; thecae 4.1-4.5 mm long, slightly prognathous, without basal appendage, papillate; tubules 2, free, straight, 4-4.2 mm long, smooth, dehiscing by introrse slits, 2.7-3.5 mm long. Nectary not pulvinate, slightly concave in vivo, glabrous; style 15-17 mm long, included; stigma punctiform. Berry unknown.

Distribution and ecology.

Psammisia pseudoverticillata is endemic to Antioquia (Colombia) and it is only known by the type specimen collected in Las Orquídeas National Park. It is known to flower in January and February. It grows in humid montane forests at 1600-1850 m.

Etymology.

The species epithet refers to the clustered tendency of the leaves.

Preliminary conservation status.

Psammisia pseudoverticillata it is only known by the type specimen collected in montane forests of Las Orquídeas National Park. Only one individual has been observed throughout several years of fieldwork. Currently, montane forest, and the park in general, suffer from degradation product of human activities (agriculture, selective logging, livestock), therefore I consider this species vulnerable due to the small area it occupies, its perceived scarcity, and current habitat threats.

Discussion.

Apparently, Psammisia pseudoverticillata is the only in the genus with seemingly verticillate leaves; only Psammisia oppositiflora Luteyn has opposite or subopposite leaves. Psammisia pseudoverticillata is morphologically closer to Psammisia orthoneura but the latter is differentiated because of its evenly distributed glabrous leaves (vs. leaves clustered, glabrate with minute hairs in Psammisia pseudoverticillata ); obscurely articulate pedicels or apparently continuous with the calyx (vs. articulate); shorter (7-8 mm long), cupuliform, terete calyces (vs. 8-11 mm long, ellipsoid, with 5 well-defined angles); terete and shorter corollas (12-13 mm long vs. 5-angled, 12-19 mm long); and its staminal connectives with obsolete spurs (according to protologue) (vs. without spurs). A plant collected in La Serranía de los Paraguas (Valle del Cauca, Municipio El Cairo), where several Ericaceae novelties have recently been found ( Pedraza-Peñalosa 2008), was identified by James L. Luteyn as Psammisia aff. orthoneura . This specimen (Luteyn 12330) may belong to Psammisia pseudoverticillata . However, the flowers are too immature to make an accurate identification given slight differences in leaf shape.