Pitcairnia singularis Flores-Argüelles, Espejo & López-Ferr., 2017

Flores-Argüelles, Alejandra, Espejo-Serna, Adolfo & López-Ferrari, Ana Rosa, 2017, Pitcairnia singularis (Pitcairnioideae, Bromeliaceae), a new species from Jalisco, Mexico, Phytotaxa 291 (4), pp. 275-280 : 275-279

Pitcairnia singularis Flores-Argüelles, Espejo & López-Ferr. , spec. nov. ( Figs. 1–3 )

The new species is characterized by the following: deciduous normal leaves without distinct petioles; inflorescence simple, with 14–20 pedicellate, secund, white flowers; petals 1.5–1.7 cm long, without basal appendages.

Type:— MEXICO. Jalisco: municipio de Puerto Vallarta, Ojo de Agua, 20° 31’ 20.22” N, 105° 11’ 37.27” W, 1195 m, bosque de Quercus , 22 August 2013 (fl), A. Flores-Argüelles & A. R. Romero-Guzmán 776 (holotype: UAMIZ, isotype: IBUG).

Plant saxicolous, perennial, acaulescent, cespitose, 15–25 cm tall in flower, slightly bulbous. Roots fibrous. Leaves 2–6, dimorphic, epetiolate, margins entire; outer reduced leaves sheath like, dark brown, membranous, oblong, 1.3 ‒ 4.2 cm long, 2.2 ‒ 3.7 mm wide at widest point, glabrous on both surfaces, conspicuously nerved, apically attenuate; inner normal leaves with sheaths triangular to ovate, 11.3 ‒ 16.5 mm long, 5.8 ‒ 8.7 mm wide at the base, dark brown, leaf-blades deciduous, green, linear, 10.8 ‒ 36 cm long, 1.6 ‒ 4.3 mm wide at widest point, conspicuously nerved, glabrous on both surfaces, present when flowering. Inflorescence terminal, simple, erect, racemose; peduncle green, erect, terete in cross section, 13–17 cm long, ca. 1 mm in diameter when dry, glabrous; peduncle bracts membranous, green, erect, narrowly triangular, 1.7 ‒ 5.2 cm long, 0.37 ‒ 0.74 mm wide at base; raceme 5.5–7 cm long, glabrous, 14–20 polystichously flowered; rachis wholly visible; floral bracts white-greenish, straw colored in dried specimens, narrowly triangular, long attenuate, membranous, 4 ‒ 7(–10) mm long, ca. 0.7 mm wide, erect, the apex acute, glabrous; flowers secund at anthesis, slightly zygomorphic, pedicellate; pedicels linear, 1.5 ‒ 6.9 mm long, flattened, glabrous except lepidote apically; sepals free, white, narrowly triangular, 9.5–11 mm long, 1.4–1.6 mm wide at the base, the two adaxial ones carinate, glabrous, acute; petals white, oblanceolate-spatulate, 1.5–1.7 cm long, 3.7–4 mm wide at widest point, without basal appendages, acute; stamens all equal in length; filaments white, strap shaped, linear, 11–12 mm long; anthers yellow, linear, 3.4–3.7 mm long, sagittate; ovary ovoid, 3–4 mm long, ca. 1.6 mm in diameter; style linear, 14–15 mm long; stigma white, conduplicate-spiral. Capsules red-brownish, ovoid, trigonous, 7.5–8 mm long, 2.5–3 mm in diameter at its widest part, apex rostrate, septicide; seeds light brown, fusiform, 1.8–2 mm long, long bicaudate.

Etymology:— The specific epithet refers to the singular characteristics of the new species that distinguish it from any other member of the genus.

Distribution, habitat and phenology:— Pitcairnia singularis is known only from the Pacific slopes of Sierra del Cuale, in the municipality of Puerto Vallarta, Jalisco ( Fig. 3 ). It grows in oak and open pine-oak forests ( Fig. 1C ) with Quercus magnoliifolia Née (1801: 268) , Brahea sarukhanii Quero (2000: 110) , Bejaria mexicana Bentham (1839: 15) , and Pinus maximinoi Moore (1966: 8) . This saxicolous bromeliad grows between 1195 and 1213 m elevation near water streams among shaded, moist boulders ( Figs. 1B–C ), with other saxicolous plants like Pitcairnia imbricata ( Brongniart 1841: 369) Regel (1868: 135) , Sobralia decora Bateman (1841 : t. 26), and Anthurium halmoorei Croat (1983: 301) . It flowers and fruits from August to December.

Additional specimens examined (paratypes):— MEXICO. Jalisco: municipio de Puerto Vallarta, Ojo de Agua, 20°31’0.96” N, 105°12’ 12.71” W, 1213 m, bosque abierto de Pinus - Quercus , 1 December 2013 (fr), A. Flores-Argüelles & A.R. Romero-Guzmán 896 (IBUG); municipio de Puerto Vallarta, Ojo de Agua, 20°31’20.22” N, 105°11’37.27” W, 1195 m, bosque de Quercus , 1 August 2014 (fl), A. Flores-Argüelles & A.R. Romero-Guzmán 930 (MEXU, UAMIZ). Comments:— Pitcairnia singularis grows in an area of high diversity and endemism. Several species have recently been described from the Sierra del Cuale, such as Hyptis cualensis González & Castro (2014: 154) , Salvia cualensis González (2012: 50) , and S. cualensis var. perezii González (2012: 53) , all members of the Lamiaceae .

In his treatment of Pitcairnia for Flora Novo Galiciana, McVaugh (1989) included eight species in Jalisco ( P. compostelae McVaugh (1989: 25) , P. cylindrostachya Smith (1937: 25) , P. heterophylla (Lindey 1840: t.71) Beer (1857: 68), P. imbricata , P. karwinskyana (s. l.) Schultes & Schultes (1830: 1239), P. micheliana André (1901: 576) , P. oaxacana Smith (1937: 25) , and P. palmeri ( Watson 1887: 456) . Espejo-Serna et al. (2004) reported nine species (additional: P. loki-schmidtii Rauh & Barthlott (1987: 18) , P. roseana Smith (1937: 27)) , and P. jaliscana Watson (1887: 456) , considered by McVaugh as synonym of P. karwinskyana ; excluding: P. compostelae , restricted to Nayarit). Seven of these species have red petals, and only two ( P. loki-schmidtii and P. imbricata ) have white to greenish white or yellow petals. However, all of the species have much longer petals (40–80 mm) than those of the new species proposed here (15–17 mm). A key for the identification of all species of Pitcairnia present in the state of Jalisco, Mexico, is given below.

1. Inflorescence capitate, sessile, peduncle very short or absent, rachis inconspicuous .......................................................................... P. heterophylla

- Inflorescence racemose, long pedunculate, rachis conspicuous.........................................................................................................2

2. Sepals 9–11 mm long; petals 15–17 mm long, white....................................................................................................... P. singularis

- Sepals 20–30 mm long; petals 40–80 mm long, red, yellow or white to greenish-white..................................................................3

3. Normal leaf-blades 3–5 cm wide, petiolate, not deciduous along a straight transverse line..............................................................4

- Normal leaf-blades 0.5–2 cm wide, never petiolate, deciduous along a straight transverse line.......................................................5

4. Floral bract shorter than the pedicel, exposing most or all of the flower; petals red; plants in flower to 60 cm high..... P. oaxacana

- Floral bract covering most or all of the flower; petals yellow or white; plants in flower to 100 cm high....................... P. imbricata

5. Petals white to greenish white, elliptic, ca. 2.5 cm wide, appendaged, corolla campanulate, actinomorphic ........... P. loki-schmidtii

- Petals red, oblong to oblong-spathulate, 1–1.5 cm wide, not appendaged, corolla tubular, zygomorphic........................................6

6. Pedicels not over 2 mm long..............................................................................................................................................................7

- Pedicels 4–30 mm long......................................................................................................................................................................8

7. Sepals and rachis of inflorescence densely and persistently lepidote ................................................................................. P. roseana

- Sepals and rachis of inflorescence glabrous or almost glabrous at anthesis......................................................................................9

8. Flowers clearly secund; floral bracts shorter than some of the pedicels ............................................................................. P. palmeri

- Flowers not at all secund; floral bracts equaling or exceeding the pedicels ..................................................................... P. jaliscana

9. Peduncle bracts lance-triangular, exposing much of the peduncle ................................................................................ P. micheliana

- Peduncle bracts broadly ovate, ample, concealing the peduncle............................................................................ P. cylindrostachya

Figures

FIGURE 1. A. Plants in flower at type locality. B. Detail of the basal portion of Pitcairnia singularis, showing the reduced sheath like and the normal leaves. C. Oak forest habitat of P. singularis Flores-Argüelles, Espejo & López-Ferr.

FIGURE 2. Holotype of Pitcairnia singularis Flores-Argüelles, Espejo & López-Ferr.

FIGURE 3. Known distribution of Pitcairnia singularis Flores-Argüelles, Espejo & López-Ferr.