Pitcairnia frequens L.B.Sm. & B. Holst ex Saraiva & Forzza

SARAIVA, D. P. & FORZZA, R. C., 2012, Pitcairnia frequens (Bromeliaceae), a neglected new species from Morro dos Seis Lagos, Amazonas, Brazil, Phytotaxa 69 (1), pp. 57-63 : 58-60

Pitcairnia frequens L.B.Sm. & B. Holst ex Saraiva & Forzza sp. nov. ( Fig. 1–4 )

Pitcairnia frequens is related to P. armata Maury (1889: 270) and P. maguirei Smith (1960: 17) chiefly because its linear and serrate leaves, sessile flowers, unappendaged petals, included stamens and style, and alate seeds. However P. armata has it leaf-sheaths broadly ovate that form a pseudobulb; upper peduncle bracts entire; sepals asymmetrical, alate-carinate and its pale green petals. P. maguirei differs by its nerved floral bracts, with a narrow pale margin; 4 cm long sepals; 6 cm long and pale green petals.

Type: — BRAZIL. Amazonas: São Gabriel da Cachoeira, Morro dos Seis Lagos, Lago do Dragão , 66°40' 59"W, 0°17' 11"N, 27 August 2011, (fl.), M . H . Terra-Araujo , F . M . Costa , M . M . P. Souza , S . M . Esteves , C . R . Boelter , J . Meirelles , C . E . Zartman , A . M . Silveira & D. P . Saraiva 221 (Holotype: RB!, isotype: INPA!) .

Plant saxicolous, propagating by slender rhizomes, the flowering stem ca. 133 up to 200 cm tall. Leaves rosulate, arched-recurving, monomorphic, thinly coriaceous; sheaths ovate, ca. 4–22 × 7–25 mm, brownish-green, nearly glabrous, entire; blades linear, not narrowed at base, persistent, archedrecurving, 89–112 × 1–1.8 cm, nerved, green, densely white lepidote, apex acuminate, margins densely spinose; spines brown, complanate, antrorse, 1–1.3 mm long. Inflorescence erect, ca. 95–130 cm long, distinctly exceeding the leaves. Peduncle 5–8 mm diam., greenish-red, white floccose distally but soon sparsely so; peduncle bracts, the basal ones foliaceous and distinctly exceeding the internodes, the upper ones narrow triangular-lanceolate, acuminate, erect, shorter than the internodes, 2.1–4 × 0.6–1.1 cm, green, woolly white lepidote. Fertile part of the inflorescence simple (spike) or few-branches laxly arranged, erect, 30–60 cm long, the rachis slightly stout, 5–7 mm diam., terete, pinkish-red, soon glabrous. Floral bracts ovate-laceolate, acute, 6–7 × 4 mm, entire, thin in texture, pinkish-red, spreading, glabrous, shorter than the sepals. Flowers, ca. 60–160, 25– 30 mm long, subdensely arranged, spreading at anthesis and afterwards, sessile, actinomorphic. Sepals narrowly triangular-lanceolate, ecarinate, acuminate, erect, 16–18 × 4 mm, pinkish-red, glabrous. Petals spatulate, acuminate, ca. 27 × 5 mm, pinkish-red, erect except for the slightly recurved apex, unappendaged, glabrous. Stamens shorter than the petals, free; filaments white; anthers linear, 5–6 mm long, attached near the base, the base bifid, the apex obtuse, yellow. Stigma capitate, spiralate, conduplicated, included at anthesis, the stigmatic lobes pinkish-red. Ovary fusiform, 4/7 superior, glabrous, placentation axilar. Ovules many, winged. Fruits a capsule, seeds winged.

Anatomy: —The adaxial and abaxial surfaces are smooth ( Fig. 2A ). A uniseriate epidermis covers the leaf. The internal periclinal cell walls have secondary thickenings on both the adaxial and abaxial surfaces. There are U-shaped thickenings on these walls ( Fig. 2C ). Peltate scales are present on the adaxial and abaxial epidermis. The number of stalk cells is five ( Fig. 2E ). The leaf is hypostomatic, and subsidiary and guard cells are placed at the same level of the epidermis ( Fig. 2D ). Two layers of sclerenchymatic hypodermis, with secondary thickenings, are present in the adaxial and abaxial mesophyll portions ( Fig. 2C,D ). An aquiferous hypodermis with thin cell walls is found essentially in the adaxial portion. This hypodermis has rounded cells ( Fig. 2A ). Palisade chlorenchyma is present giving the appearance of an abrupt transition between the aquiferous tissue and the chlorenchyma. Chlorenchymatic inter-vascular cells are short-armed cells with less- distinct air lacunae ( Fig. 2A ). The vascular bundles are collateral, with smaller or larger gauges. These vascular bundles are surrounded by sclerenchymatic sheaths. These sheaths are in direct contact with aquiferous hypodermis, in both adaxial and abaxial positions. Fibers are present in the phloem ( Fig. 2B ).

Paratype: — BRAZIL. Amazonas: São Gabriel da Cachoeira, Morro dos Seis Lagos, Lago do Dragão , 400–450 m, 14 and 15 October 1987 (fl.), W. A. Rodrigues, D. C. Daly, P. J. M. Maas, D. W. Stevenson, R. P. de Lima, J. F. Ramos & J. C. Oliveira & C. Farney 1712 ( NY!, RB! [2 sheets])

Etymology: —The name given by L.B. Smith is related with the high frequency of the species in the herbaceous strata of the hill top.

Distribution and Habitat: — Pitcairnia frequens is an endemic species of the Morro dos Seis Lagos top in São Gabriel da Cachoeira, Amazonas, Brazil —Amazonian domain ( Fig. 4 ). The undulating plateau of the hill has six lakes, and the Pitcairnia is growing near the Lakes Dragão and Verde as a rupicolous plant on sunexposed surfaces or in places slightly shaded by shrubs ( Fig. 3 ).

Conservation status: —According to the IUCN Red List ( IUCN 2011), the species should be treated as least concern (LC). Due to its large population size growing at the top of a difficult to access hill, and for its placement in the intersection of three protected areas: Pico da Neblina National Park, Morro dos Seis Lagos Biological Reserve, and Balaio Indigenous Park ( Fig. 4 ).

Note: —The latest voucher (Saraiva 221) was chosen here to be the holotype instead of the oldest, sent to New York Botanical Garden Herbarium (Farney 1712), and appointed by L.B. Smith & B. Holst as new species. This decision was taken to ensure a more detailed description of the species.

Figures

FIGURE 1. Habit of Pitcairnia frequens. A. Flowering habit. B. Detail of spine and scales in adaxial surface. C. peduncle bract. D. Flower with floral bracts. E. Floral bract. F. Sepals. G. Petal and androecium. H. Gynoecium. I. Stigma. J. Transversal cut of ovary, showing its axial placentation.

FIGURE 2. Micrographs of Pitcairnia frequens in cross section. A. General aspect of the leaf with smooth adaxial and abaxial contour, and abrupt transition between the aquiferous tissue and the chlorenchyma. B. Sclerenchymatic sheaths surrounding the vascular bundles and phloem fibers. C. Adaxial epidermises, sclerified hypodermis, and aquiferous hypodermis. D. Stomata on abaxial epidermis. E. Pedicle of a peltate scale on abaxial surface. AH-aquiferous hypodermis, EP-epidermis, SC-substomatal chamber, SH-sclerified hypodermis. Scale bars: A-200 mm; B-100 mm; C, D, E-50 mm.

FIGURE 3. Pitcairnia frequens occurrence places at Morro dos Seis Lagos and inflorescences details. A. Verde Lake.B. Dragão Lake. C. Rupiculous population in the Verde Lake. D. Population between shrubs near Dragão Lake. E. Compound inflorescence. F. Simple inflorescence. G. Spreading flowers.

FIGURE 4. Intersection of the three areas of protection that include the Morro dos Seis Lagos (Hill of the Six Lakes). The large and darkest spot into Morro dos Seis Lagos Biological Reserve represents Morro dos Seis Lagos. It is near BR-307 that connects the municipalities of São Gabriel da Cachoeira to Cucuí.