Novelties in the genus Viridantha Espejo (Tillandsioideae, Bromeliaceae) Author Hernandez-Cardenas, Rodrigo Alejandro Author Diaz, Alejandra Serrato Author Lopez-Ferrari, Ana Rosa Author Espejo-Serna, Adolfo text PhytoKeys 2019 132 99 110 http://dx.doi.org/10.3897/phytokeys.132.36959 journal article http://dx.doi.org/10.3897/phytokeys.132.36959 1314-2003-132-99 54E5CD4A687F5D52BCC1FE2267CB290E 3478685 Viridantha uniflora Hern.- Cardenas , Espejo & Lopez-Ferr . sp. nov. Figs 2 , 3 Diagnosis. Viridantha uniflora is similar to V. boqueronensis but differs in the shape (square vs. ovate to triangular) and the width of the leaf sheath (0.7-0.8 cm vs. 1 cm); the width (0.4-0.5 cm vs. 0.7-1.3 cm) of the spikes, the number of flowers per spike (always 1 vs. 2-5); and in the shape of the floral bract (ovate vs. elliptic). Type. MEXICO. Oaxaca: Distrito de Juxtlahuaca, municipio de Santos Reyes Tepejillo, en los alrededores del boqueron de Santos Reyes Tepejillo ( 17°26'58"N , 97°56'29"W ), 1960 m a.s.l., 21 April 2018, R. Hernandez-Cardenas , E. Negri & J. Conde 2156 (holotype: UAMIZ!; isotype: MEXU!). Description. Plants saxicolous, flowering 7-10 cm tall, 7-9 cm diameter; rosettes acaulescent, solitary or caespitose, falcate in outline. Leaves numerous, shorter or equalling the inflorescence; sheaths pale brown on both surfaces, nearly square, 0.8-1 cm long, 0.7-1 cm wide, glabrous towards the base on both surfaces; blades falcate, densely greyish lepidote, narrowly triangular, 3-6 cm long, 0.3-0.4 cm wide, apical portion long attenuate. Inflorescence pedunculated, falcate, one-branched, with 3-5 spikes; peduncle 2.5-3.5 cm long, 0.2-0.3 cm diameter, covered by the bracts of the peduncle; peduncle bracts similar to the leaves but reducing in size towards the apical portion, densely greyish lepidote; spikes green, erect and appressed, flattened, elliptic, 1.3-1.5 cm long, 0.4-0.5 cm wide; flowers erect and appressed, only one per spike; floral bracts green to green-brownish, ovate, 1-1.5 cm long, 0.5-0.6 cm wide, apex acute to acuminate, ecarinate to slightly carinate at the apex, glabrous adaxially, lepidote abaxially; sepals green, lanceolate, 1-1.3 cm long, 0.3-0.4 cm wide, apex acute, the two adaxial ones carinate, both surfaces glabrous or lepidote abaxially mainly on the keel; petals dark green, narrowly oblong, 1.5-1.8 cm long, 0.2-0.3 cm wide, apex rounded to obtuse; filaments white, 0.8-1.2 cm long, included; anthers pale green, 1.2-1.5 mm long; ovary green, ellipsoid, 2.5-3 mm long, 2-3 mm diameter; style white, 8-10 mm long; style branches green. Capsules not seen. Habitat and ecology. Viridantha uniflora is only known from the boqueron of the Santos Reyes Tepejillo municipality, located in the Sierra Madre del Sur in the northwest region of the state of Oaxaca, where it grows on vertical walls in dry oak forests and tropical deciduous forests. The plants of V. uniflora grow in colonies, between 1700 and 1900 m a.s.l., on the cliffs of the boqueron amongst other saxicolous herbs. ( Figs 2 , 3 ). Figure 3. Morphological comparison between Viridantha boqueronensis , V. penascoensis and V. uniflora Hern.- Cardenas , Espejo & Lopez-Ferr . V. uniflora A-B habit E-F , M spikes G plant with inflorescence H pistil I stamens J petals K sepals L floral bract (voucher: Hernandez-Cardenas et al. 2156 , UAMIZ). V. boqueronensis C spike (voucher: K. and R. Ehlers EM7851 , MEXU). V. penascoensis D spike (voucher: Hernandez-Cardenas and Sarabia 2116 , UAMIZ). Photographs A-B by E. Negri Lavin ; C-M by R. Hernandez-Cardenas . Phenology. The plants of Viridantha uniflora bloom in April and May. Etymology. The specific epithet refers to the presence of one flower per spike, condition only known in the proposed taxon. Observations. Plants of Viridantha uniflora had previously been collected by J.I. Calzada 20057 (MEXU), but had been wrongly identified as V. atroviridipetala (Matuda) Espejo. However, V. uniflora differs from V. atroviridipetala in the outline shape of the rosettes (falcate vs. spherical); in the shape of the leaf sheaths (square vs. oblong to ovate); in the shape of the floral bracts (ovate vs. lanceolate to narrowly triangular) and in the number of flowers per spike (1 vs. 2-5). Viridantha boqueronensis and V. penascoensis grow in nearby locations to the type locality of V. uniflora , but without overlapping its distributions. These species share the saxicolous habit and the falcate rosettes in outline. However all these species are easily distinguishable from the newly proposed taxon (Table 2 ). Viridantha uniflora differs from V. penascoensis in the inflorescence (branched vs. simple); in the length and in the colour (green vs. red-pink) of the spikes (1.3-1.5 cm vs. 2-3 cm). Viridantha uniflora differs from V. boqueronensis in the shape of the leaf sheaths (square vs. ovate to triangular); in the number of flowers per spike (1 vs. 2-5); in the colour of the spikes (green vs. green with red-pink); in the shape of the floral bracts (ovate vs. elliptic); and in the presence or not of a keel on the floral bracts (absent or visible only in the apex vs. present along the bract. Table 2. Morphological differences amongst Viridantha boqueronensis , V. penascoensis and V. uniflora .
Characters V. boqueronensis V. penascoensis V. uniflora
Leaf sheaths size (cm) 0.9-1.4 x 0.8-1 0.6-1 x 0.7-0.8 0.8-1 x 0.7-0.8
Leaf sheaths shape Ovate to triangular Broadly ovate to square Square
Leaf blades size (cm) 4-7 x 0.3-0.4 2.5-4 x 0.2-0.3 3-6 x 0.3-0.4
Spikes colour Green with red Red to pink Green
Spikes number 5-7 1 3-5
Flowers number per spike 2-5 2-3 1
Spike size (cm) 1.5-3.5 x 0.7-1.3 2-3 x 0.8-1 1.3-1.5 x 0.4-0.5
Floral bracts size (cm) 1.2-1.7 x 0.5-0.8 1.5-2 x 0.5-1 1-1.5 x 0.5-0.6
Floral bracts shape Elliptic Ovate Ovate
Floral bracts keel Present Absent or visible only in the apex Absent or visible only in the apex
Sepals size (cm) 1-1.3 x 0.3-0.35 1.3-1.5 x 0.3-0.5 1-1.3 x 0.3-0.4
Sepals shape Narrowly elliptic Ovate Lanceolate
Additional specimens examined (paratypes). MEXICO, Oaxaca: Distrito Santiago Juxtlahuaca, municipio de Santos Reyes Tepejillo. 3 km al N de Santos Reyes Tepejillo rumbo a Corral de Piedra ( 17°27'N , 97°57'W ), 1770 m a.s.l., 20 July 1995, J. I. Calzada 20057 (MEXU); en los alrededores del boqueron de Santos Reyes Tepejillo ( 17°26'58"N , 97°56'29"W ), 1960 m a.s.l., 18 March 2017, R. Hernandez-Cardenas , F. Gomez y A. Gonzalez 2120 (UAMIZ). To facilitate the identification of the species of Viridantha , we include an artificial key for all representatives of the genus. Key to the species of Viridantha
1 Rosettes irregular or falcate in outline 2
- Rosettes spherical in outline 8
2 Inflorescence branched 3
- Inflorescence simple 5
3 Flower one per spike, spikes 1.3-1.5 cm long V. uniflora
- Flowers two or more per spike, spikes longer than 1.6 cm 4
4 Leaf blades 3-4 mm wide; floral bract elliptic V. boqueronensis
- Leaf blades 5-8 mm wide; floral bract ovate V. secundifolia
5 Rosettes falcate, blades falcate 6
- Rosettes irregular, blades squarrose 7
6 Plants longer than 5.1 cm; spikes terete V. curvifolia
- Plants shorter than 5 cm; spikes elliptic, flattened V. penascoensis
7 Leaf sheaths broadly ovate to oblong; peduncle (in anthesis) longer than 4.1 cm and lesser than 2 mm diameter V. tortilis
- Leaf sheaths broadly oblong to square; peduncle (in anthesis) shorter than 4 cm and larger than 4 mm diameter V. lepidosepala
8 Inflorescence conspicuously pedunculate, peduncle longer than 4.1 cm 9
- Inflorescence sessile or peduncle shorter than 3.5 cm 11
9 Inflorescence simple, longer than 3.1 cm, flattened to terete, rarely with two small lateral spikes V. ignesiae
- Inflorescence branched, shorter than 3 cm long, flattened 10
10 Leaf blades wider than 2.1 mm; floral bracts triangular to ovate, carinate V. plumosa
- Leaf blades narrower than 2 mm; floral bracts elliptic to oblong, ecarinate to carinate only at the apex V. caballosensis
11 Leaf blades wider than 7.1 mm; anthers black V. mauryana
- Leaf blades narrower than 7 mm; anthers green 12
12 Plants short caulescent; floral bracts elliptic V. yagulensis
- Plants acaulescent; floral bracts variable in shape but never elliptic 13
13 Spikes longer than 3.1 cm and wider than 1.1 cm 14
- Spikes shorter than 3 cm and narrower than 1 cm 15
14 Leaf sheaths broadly ovate to square, blades wider than 4.1 mm; sepals shorter than 1.5 cm V. rzedowskiana
- Leaf sheaths narrowly oblong, blades narrower than 4 mm; sepals longer than 1.6 cm V. grandispica
15 Spikes 3 or less; floral bracts shorter than 1.5 cm; sepals lanceolate V. teloloapanensis
- Spikes 4 or more; floral bracts longer than 1.6 cm; sepals narrowly elliptic V. atroviridipetala