Barbacenia purpurea Hook.

Barbacenia purpurea Hooker

Barbacenia purpurea Hooker, Bot. Mag., 54, pl. 2777, 1827.—Seubert in Martius, Fl. Bras., 3(1):67, pl. 8: fig. 7, 1847.—L. B. Smith, Contr. U.S. Nat. Herb., 35:278, 1962.—Ayensu, Smithsonian Contr. Bot., 15:55, fig. 18d–f, pl. 39a–c, 1974.

Pleurostima purpurea (Hooker) Rafinesque, Fl. Tellur., 2:97, 1836.

TYPE.—Brazil, cultivated in England, August 1827, Hooker from Herbert (K, holotype(?) or lacking this the original description and plate).

DISTRIBUTION.—Brazil: Rio de Janeiro (city).

29. Barbacenia andersonii L. B. Smith & Ayensu, new species

A B. purpurea, cui verisimiliter affinis, tepalis obtusis, appendicium lobis dilatatis rotundatisque differt.

Caudex (incompletely known) erect (?), simple, over 8 cm or to 40 cm long (!Anderson—[plant] 70 cm tall), 8 mm thick including leaf-sheaths. Leaves 3-ranked, sulcate on both sides, glutinous; sheaths apically exposed for 5 mm, dark brown beneath; blades very narrowly triangular, filiform-attenuate, 15 cm long, 8 mm wide, serrulate on margins and keel.

Scapes 1 or 2, 32 cm long (above the leaf-sheaths) laxly vestite with minute dark stipitate glands. Flowers purple, dark-glandular. Ovary ellipsoid, 10 mm long; perianth-tube above ovary cylindric, 2 mm long. Anthers 12 mm long; coronoid appendages spatulate, bifurcate with rounded lobes, 22 mm long. Style subulate with subapical stigmas.

LEAF ANATOMY (Anderson 6704).—Surface View: Hairs: few tufts present on outer edges of lamina. Epidermis: adaxial and abaxial cells square to rectangular; thin-walled; in long rows across the surface; interspersed with few rounded areas of irregularly shaped cells. stomata: tetracytic; 27 × 21 μm; present only in abaxial furrows.

Transverse Section of Lamina: Dorsiventral ? isolateral; V-shaped with small median adaxial groove. Both surfaces slightly undulating with slight furrows on abaxial surface. Conspicuous grooves occur on adaxial side of bundles. Epidermis: cells on both surfaces rounded to dome-shaped; few conical; thin-walled. Subjacent to epidermis is one layer of rounded, thin-walled parenchyma cells. Adaxial parenchyma larger above midvein; few sclerenchyma cells present in adaxial parenchyma layer. Cuticle: slightly thickened and undulating on both surfaces. Stomata: present in abaxial furrows only; outer and inner ledges present; stomata flush with epidermal surface; large substomatal chamber present. Mesophyll: five layers of elongated cells followed by 7 or 8 layers of rounded, compactly arranged cells. Vascular bundles: 65; commissural bundles observed. One or two large vessels present in each bundle; mostly one. Two phloem units lying laterally in flanges of Y-shaped abaxial girder. Inverted Y-shaped adaxial girder present on each bundle. Midvein has no adaxial girder, but has conspicuously rounded abaxial sclerenchyma. Bundle sheath completely surrounding each bundle. Crystals: none observed. Tannins: few present in mesophyll.

TYPE.—In cerrado with sandstone outcrops, 27 km by road north of Alto Paraíso, Goiás, Brazil, 1750 m alt, 9 March 1973, Anderson 6704 (US, holotype; NY; UB, isotypes).

DISTRIBUTION.—Known only from the type-collection.

Barbacenia purpurea Hooker

SPECIMENS EXAMINED.—A. L. Schott s.n. US 151098.

SURFACE VIEW.—Hairs: none present. Epidermis: adaxial cells rounded; abaxial cells square to rectangular; cells thin walled on both surfaces. Stomata: paracytic, 21 × 6 μm; present on abaxial surface.

TRANSVERSE SECTION OF LAMINA.—Isolateral; V-shaped with margins turned inversely. Adaxial and abaxial surfaces furrowed about one-fourth thickness of blade. Epidermis: cells on adaxial surface dome shaped to rectangular; cells on abaxial surface rounded to dome shaped; thick walled on both surfaces. Cuticle: thin and slightly ridged on adaxial and abaxial surfaces. Stomata: present in abaxial furrows; substomatal chamber present. Mesophyll: undifferentiated. Some large translucent cells radially arranged above the midvein; few translucent cells present in mesophyll. Vascular bundles: 37; commissural bundles not observed. One to two large vessels present in each vascular bundle, mostly one. Two phloem units arranged laterally in flanges of Y-shaped adaxial girder. Inverted Y-shaped adaxial girder present on each vascular bundle. Both girders extend laterally below epidermis on both surfaces. Vascular bundles surrounded by bundle sheath. Crystals and tannins: none observed.

Barbacenia purpurea là một loài thực vật có hoa trong họ Velloziaceae. Loài này được Hook. miêu tả khoa học đầu tiên năm 1827.