Dyckia montezumensis Leme, 2012
publication ID |
https://doi.org/ 10.11646/phytotaxa.67.1.2 |
persistent identifier |
https://treatment.plazi.org/id/693287B2-075A-356A-94A1-FD87542EFEB4 |
treatment provided by |
Felipe |
scientific name |
Dyckia montezumensis Leme |
status |
sp. nov. |
Dyckia montezumensis Leme View in CoL , sp. nov. ( Figs. 8 View FIGURE 8 , H–M, 9 View FIGURE 9 , A–G)
The closest relative of this new species is Dyckia atratiflora . This new species differs by the smaller size when in bloom, reduced number of leaves, inflorescence not erect, shorter first order branches, shorter basal floral bracts, flowers not polystichously arranged, and by the yellow style.
Type:— BRAZIL. Minas Gerais: Montezuma, Parque Estadual de Montezuma , topo de morro no entorno da represa da COPASA, 1012 m elevation, 15º 09’ 53” S, 42º 29’ 16” W, 26 May 2010, E GoogleMaps . Leme 8315 & R . Oliveira (holotype RB!) .
habit of sterile specimens.
Plants terrestrial, flowering ca. 115 cm high. Leaves ca. 10 in number, sparsely rosulate, thickly coriaceous; sheaths suborbicular, ca. 2.5 × 4.5 cm, glabrous and whitish toward the base; blades narrowly triangular, distinctly canaliculate, arcuate, 37–50 cm long, 2.2–2.5 cm wide at the base, ca. 2.5 mm thick near the base, dark green to reddish-wine, opaque, densely white lepidote abaxially with the trichomes obscuring the color of the blades, adaxially densely white lepidote with the trichomes arranged along the intercostal areas and not obscuring the color of the blades, distinctly nerved on both sides, apex long acuminate-caudate, margins sparsely white lepidote to glabrous, sparsely spinose, spines 1.5–2.5 mm long, 7–20 mm apart, narrowly triangular, antrorse or retrorse, dark castaneous, glabrous. Peduncle at a 45° angle, ca. 72 cm long, 3.5–4.5 mm in diameter, inconspicuously and sparsely white lepidote to glabrous, smooth, dark green to dark purplish-wine; peduncle bracts broadly ovate to suborbicular at the base with a narrowly sublinear-triangular, carinate blade, apex acuminate-caudate, 10–40 × 7–10 mm, stramineous, strongly nerved, inconspicuously white lepidote, erect, the basal ones remotely spinulose, many times shorter than the internodes, the upper ones entire. Inflorescence at an angle of 45°, ca. 35 cm long, bearing a simple branch at the base, laxly to subdensely flowered, rachis straight to flexuous toward the apex, terete, dark purplish-wine, subdensely white lepidote, 1.5–3 mm in diameter; primary bracts resembling the basal floral bracts, many times shorter than the stipe; primary branch ca. 7.5 cm long, forming an internal angle of 30° with the main axis, bearing ca. 4 flowers more or less polystichously arranged, rachis flexuous, terete, 1.5–2 mm in diameter, subdensely and minutely white lepidote, dark purplish-wine, stipe ca. 4 cm long, ca. 2 mm in diameter, dark purplish-wine; floral bracts broadly ovate, acute to acuminate, 3–7 × 2–4.5 mm, entire, ecarinate, inconspicuosly white lepidote, slightly exceeding to shorter than the pedicels, distinctly nerved. Flowers ca. 25 in number, 16–18 mm long, subspreading to forming an internal angle of ca 45°, distichously to subpolystichously arranged; pedicels distinct, 4 × 2–3 mm, dark purplish-wine to nigrescent, subdensely white lepidote; sepals symmetric, ovate, distinctly convex, apex obtuse to often emarginate, ca. 6 × 5 mm, blackish-wine near the base to wine colored toward the apex, white lepidote near the base to glabrous toward the apex; petals symmetric, broadly spathulate, apex obtuse-emarginate, connate at the base for ca. 2 mm to form a common tube with the filaments, 13 × 9–11 mm, ecarinate, orange except for the wine colored apex and apical margins, forming a campanulate corolla 9–12 mm in diameter; stamens distinctly shorter than the corolla; filaments completely connate to each other above the common tube with the petals and forming a tubular structure ca. 7 mm long, orange; anthers sublinear, ca. 4 mm long, base bilobed, apex apiculate, fixed near the base; pistil 8–9 mm long, surpassed by the anthers; stigma conduplicate-spiral, papillose, orange; style ca. 1 mm long, yellowish; ovary suboblong-ovate, 7–8 mm long, ca. 2.5 mm in diameter, greenish. Capsules unknown.
Distribution and habitat:— Dyckia montezumensis is typically terrestrial, found in the shrubby Cerrado vegetation in the northern region of Minas Gerais state, not far from the border with Bahia. Its known habitat comprises a hilltop of ca. 1,000 m elevation situated inside the State Park of Montezuma, which is a planned conservation unit. Plants occur in small groups of individuals hidden in dense grass-like vegetation.
Etymology:—The name chosen for this new species refers to the county of Montezuma, where it was found within the limits of Montezuma state Park.
Observations:— Dyckia montezumensis is closely related to D. atratiflora Braun, Esteves & Scharf (2009: 84) from Goiás, central Brazil. However, the comparison of these two species is complicated because the original description of D. atratiflora presents many inconsistencies when compared to the illustration (i.e., color photographs) provided in its protologue. The inconsistencies are mainly related to: (1) inflorescence measurements (e.g., distinctly longer in the illustrations than in the description) and structure (mentioned as usually simple or sometimes slightly branched, but bearing at least 9 lateral branches in the illustration, which is a high branch number for the genus); (2) pink color described for sepals and petals, which is not indicated in the illustration and was never before reported for the genus); (3) sepal shape (lanceolate but almost always rounded at the apex in the illustrations), dimensions (described as 10 mm long but distinctly shorter according to the scales provided in the illustration), and trichome density (described as densely covered by trichomes but showing glabrous sepals in the illustration). Those inconsistencies are probably caused by sampling methods, with the use of specimens of different populations (as suggested by the visual differences in the illustrations), without proper specimen citation, as only one specimen was cited in the protologue (i.e., the holotype).
Despite these difficulties, it is possible to distinguish D. montezumensis from D. atratiflora by its smaller size when in bloom (ca. 115 cm vs. 185 cm high), with reduced leaf number (leaves ca. 10 vs. 20 to 30 in number), inflorescence forming an angle of 45° (vs. erect) with shorter first order branches (ca. 7.5 cm long vs. to 19 cm long), shorter basal floral bracts (ca. 7 mm long, vs. ca. 12 mm long), flowers more or less distichously arranged (vs. polystychous), and by the yellow style (vs. dark purple).
E |
Royal Botanic Garden Edinburgh |
R |
Departamento de Geologia, Universidad de Chile |
RB |
Jardim Botânico do Rio de Janeiro |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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