Viridantha pachycaulis Hern.
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publication ID |
https://doi.org/ 10.11646/phytotaxa.520.1.7 |
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persistent identifier |
https://treatment.plazi.org/id/5D6087AB-B37D-FFD0-36F0-DCBEFDD9F932 |
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treatment provided by |
Plazi |
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scientific name |
Viridantha pachycaulis Hern. |
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Viridantha pachycaulis Hern. -Cárdenas, Espejo & López-Ferr., sp. nov. ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 , 3B, B View FIGURE 3 1 View FIGURE 1 , B 2 View FIGURE 2 . Table 1)
The new species is similar to Viridantha yagulensis but differs in the number (2–5 vs. 5–7) and size of the spikes (3–4 × 1–1.5 vs. 2–3 × 0.8–1 cm), in the shape (ovate vs. elliptic) and length of the floral bracts (2–2.5 vs. 1.5–2 cm), in the length of the sepals (1.5–2 vs. 1.2–1.5 cm), and in its geographical distribution (Jalisco vs. Oaxaca).
TYPE:— MÉXICO. Jalisco: municipio de San Cristóbal de la Barranca, camino que va de San Cristóbal de la Barranca a la Lobera, Mesa de los Caballos (21°05′11.3″N, 103°29′01.7″W), 1,584 m, April 1, 2020 GoogleMaps , R. Hernández-Cárdenas & S. Lara-Godínez 2429 (holotype UAMIZ!, isotypes IBUG!, MEXU!).
Plants saxicolous, flowering 10–15 cm tall, 8–12 cm in diameter; rosettes shortly caulescent, spherical in outline, solitary or forming clumps of two or three rosettes. Leaves numerous, longer than the inflorescence; sheaths pale brown on both surfaces, oblong, 15–20 mm long, 7–8 mm wide, glabrous at the base on both surfaces; blades densely grey lepidote, narrowly triangular to linear, 50–70 mm long, 3.5–4.5 mm wide, recurved, of attenuate. Inflorescence subsessile, nested in the center of the rosette, ones-branched, with 2–5 spikes; peduncle inconspicuous, 5–10 mm long, 3–4 mm in diameter; peduncle bracts similar to the leaves, longer than the inflorescence but reducing in size distally, densely grey lepidote. Spikes green to reddish-rose at the apex, erect and appressed to the peduncle, dorsiventrally flattened, elliptic, 30–40 mm long, 10–15 mm wide, 2–4 flowered; floral bracts reddish-rose at the apex, yellowish- green towards the base, ovate when extended, 20–25 mm long, 8–10 mm wide, apex acute to acuminate, nerved, carinate, glabrous adaxially, lepidote abaxially. Flowers distichous, erect and appressed to the rachis; sepals reddishrose at the apex, yellowish-green towards the base, lanceolate, 15–20 mm long, 4–5 mm wide, apex acuminate, the two adaxial ones carinate, glabrous adaxially, scattered lepidote abaxially; petals white in its basal half, to dark green in its apical half, narrowly oblong, 20–25 mm long, 3–4 mm wide, apex rounded to obtuse; stamens all equal; filaments white, filiform, 15–17 mm long; anthers pale green, 3–4 mm long; ovary green, ovoid to ellipsoid, 4–5 mm long, 2.5–3.5 mm in diameter; style white, 7–11 mm long; stigma branches green. Capsules 25–30 mm long, 5–8 mm in diameter; seeds fusiform, 2–3.5 mm long; coma 1.5–2 cm long.
Distribution and habitat: — Viridantha pachycaulis is only known from the municipality of San Cristóbal de la Barranca in Central Jalisco ( Fig. 1 View FIGURE 1 ), in the biogeographic province of Pacific Lowlands (according to Morrone et al. 2017), were it grows on vertical walls in the transition area of tropical deciduous forest to Quercus forest with species of Agave , Bursera , Fabaceae , and Quercus . There is a big plateau in this area called “Mesa de los Caballos”, on the side walls of this plateau V. pachycaulis is growing at elevations between 1,580 and 1,660 m. The new species blooms from March to April.
Etymology: —The specific epithet refers to the thick stems of the new taxon (from the Greek: παχύς (pachys) = thick; καυλος (kaulos) = stem), which is why the rosettes look very robust.
Paratypes: — MÉXICO. Jalisco: municipio de San Cristóbal de la Barranca, camino que va de San Cristóbal de la Barranca a la Lobera, Mesa de los Caballos (21°05′11.3″N 103°29′01.7″) 1,584 m, April 1, 2020, R . Hernández- Cárdenas & S. Lara-Godínez 2456 (UAMIZ!).
Observations: — Viridantha pachycaulis also has some similarities with V. atroviridipetala and V. grandispica . Nevertheless, V. pachycaulis differs from V. atroviridipetala in the height of the rosettes (10–15 vs. 5–10 cm), in the width of the leaf blades (3.5–4.5 vs. 2–3.5 mm), in the size (3–4 × 1–1.5 vs. 1.5–3 × 0.5–1 cm) and shape of the spikes (elliptic vs. narrowly elliptic), and in the shape of the floral bracts (ovate vs. lanceolate to narrowly triangular). Viridantha pachycaulis differs from V. grandispica in its habit (saxicolous vs. epiphytic), in the grow form (short caulescent vs. acaulescent), in the length of the petals (2–2.5 vs. 2.5–3 cm), and in the length of the capsules (2.5–3 vs. 4–5 cm), see also Table 1 and Figure 3 View FIGURE 3 .
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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