Anthurium rosselianum Croat, 2019

Croat, Thomas B., 2019, Anthurium rosselianum (Araceae), a new species of Anthurium section Belolonchium from Colombia, Phytotaxa 391 (2), pp. 101-107 : 101-106

Anthurium rosselianum Croat , sp. nov. ( Figs. 1–4 )

Species is a member of section Belolonchium characterized by its epiphytic habitat, short internodes, cataphylls sharply D-shaped, mostly deciduous with thick raised scar, some loose, pale brown, twisted fibers persist at the upper nodes becoming fibrous with fragments of brown epidermis, the fibers manila, cordate-sagittate blades, epunctate on the lower surface on the blades, 9 pairs of basal veins, 1 st pair free to base, sinus hippocrepiform, 12 pairs of primary lateral veins, collective veins arising from 1 st pair basal veins, 4.0 mm from margin, a short-pedunculate inflorescence with a medium reddish brown, oblong-lanceolate, broad spathe, and a weakly cylindroid tapered spadix. Particularly unusual for a member of section Belolonchium is the way the cataphylls persist. Mostly they are deciduous leaving a thick raised scar but some loose, pale brown, twisted fibers persist at the upper nodes.

Type:—COLOMBIA. Cauca: Along road between Popayán and Viente de Julio W of Popayán, 17 km W of summit, 1280 m, 2°31’18”N, 77°01’56”W, 19 July 1997, T. B. Croat & J. F. Gaskin 80112 (holotype MO!, isotype CUVC).

Epiphytic; internodes short, 3.5 cm long, 6.0 cm diam., drying medium yellow-brown, matte, with cataphyll scars that run diagonally and are prominently raised; cataphylls to 26.7–38.0 cm long, sharply D-shaped, green, thick, mostly deciduous with thick raised scar, some loose, pale brown, twisted fibers persist at the upper nodes becoming fibrous with fragments of brown epidermis, the fibers manila. Leaves with petioles 119.2 cm long, 0.8–1.2 cm diam., terete, unribbed, medium green, semiglossy, drying narrowly and obtusely sulcate, medium brown; geniculum 2.0 cm long, drying slightly paler than petioles; blades 96.0–101.5 × 65–66 cm, 1.40–1.53 times longer than broad, moderately coriaceous, cordate-sagittate, acute and weakly emarginated to gradually acuminate at apex, prominently lobed at base, broadest at petiole attachment, 0.80–0.85 times long as petioles; upper surface dark green and semiglossy above, drying medium brown and semiglossy below; lower surface slightly paler and weakly glossy above, drying reddish brown and weakly glossy below, epunctate; anterior lobe 73.0– 81.5 cm long, straight to slightly concave in upper half of anterior lobe, the distil margin broadly rounded; posterior lobes 32.0–33.0 × 21.2 cm, directed downward and inward; midrib acute and slightly paler above, narrowly raised and paler below; primary lateral veins 12 pairs, arising at a 45–55° angle, acute above and below, drying paler above, concolorous below; tertiary veins moderately obscure; collective veins arising from 1 st pair basal veins or primary lateral veins, 4.0–6.0 mm from margin. basal veins 9 pairs, 1 st pair free to base, 3 rd pair fused to 6.7 cm, 7 th and 8 th pair fused to 15.5 cm; posterior ribs gradually curved, naked 8.0– 12 cm; sinus reniform to hippocrepiform, 23.2 cm deep, 19.6 cm wide. Inflorescence short-pedunculate; peduncle 24.8–25.0 cm long; spathe medium reddish brown, oblong-lanceolate, broad, 14.2–15.0 × 6.6–8.0 cm, drying moderately coriaceous; spadix sessile, weakly cylindroid-fusiform tapered, 13.1 cm long, 1.6 cm diam., drying medium reddish brown; flowers 15–18 visible per principal spiral, drying 1.7–1.9 × 1.0– 1.7 mm; tepals moderately smooth on drying; lateral tepals 0.9 mm wide, the outer margins 3–4-sided, inner margin rounded, surface minutely papillate; stamens not yet emergent. Berries not seen.

Eponymy:—The species is named in honor of the late Allan John Rossel, formerly a Volunteer Research Associate at the Missouri Botanical Garden. After a career of working as a Systems Analysist for IBM, Al began work with the Aroid Research Group at the Missouri Botanical Garden, initially working with entering all data and images into Tropicos but his skills with computers and the many associated programs led us to have him get involved with many other aspects of aroid research. Al was exceptional with the creation of Lucid multi-entry keys to different genera of Araceae , even writing a special program to download all species data in Lucid to automatically generate vernacular species descriptions. For this work, he received the Missouri Botanical Garden Volunteer Award for Special Projects in 2015. In addition, Rossel received two monetary service awards from IBM which were donated to the Garden. Allan was so attentive to detail that he came to be our unofficial “name cop” by maintaining all the new name records to avoid using a name more than once. In addition, he was able to solve most of our computer problems quickly. After an extended bout with cancer, Allan Rossel died August 21, 2016 and is survived by his wife Carol Elaine (Leenerts) Rossel and daughters Joyce Rossel and Janet Rossel Waldeck.

Distribution:—The species is known only from the type locality in Cauca Department west of the Continental Divide.

Habit and ecology: — Anthurium rosselianum grows at 1280 m in a Lower montane rain forest life zone according to the classification of zones proposed by (Holdridge 1971).

Phenology:—Flowering in July. Further investigations are required to determine exact flowering and fruiting seasons.

Conservation status:—According to the IUCN List (2001), Anthurium rosselianum is considered as Data Deficient (DD).

Discussion:—In the Lucid Anthurium Key (Haigh et al. 2009) A. rosselianum tracks to A. bogotense Schott (1857: 302) ( Colombia) and A. brownii Masters (1876: 744) ( Costa Rica to Ecuador), both of which differ in having a much longer, narrowly tapered spadix; A. gualeanum Engler (1898: 424–425) ( Ecuador), differing by having a caviform, almost closed spathe; A. macarenense Schultes & Idrobo (1954: 183) ( Colombia), which differs in having a narrower spathe with prominent greenish lines; A. plurisulcatum Sodiro (1906: 38) ( Ecuador), differing by having leaf blades with a reniform sinus and a much longer peduncle (60–90 cm long) as well as and finally A. riofrioi Sodiro (1902: 82) ( Ecuador), which differs by its subreniform sinus and stipitate spadix.

Figures

FIGURE 1. Anthurium rosselianum. Holotype specimen: MO-4940579, sheet 1. Colombia. Cauca: Along road between Popayán and Juntas via Viente de Julio Popayán, 17 km W of summit, 1280 m, 2º31’18”N, 77º 01’56”W, 19 July 2007, T.B. Croat & J.F. Gaskin 80112. Leaf blade abaxial surface, part of basal lobe showing sinus, with outer margin, adaxial surface and complete petiole.

FIGURE 2. Anthurium rosselianum. Holotype specimen: MO-4940580, sheet 2. Colombia. Cauca: Along road between Popayán and Juntas via Viente de Julio Popayán, 17 km W of summit, 1280 m, 2º31’18”N, 77º 01’56”W, 19 July 2007, T.B. Croat & J.F. Gaskin 80112. Leaf blade, anterior lobe folded twice with adaxial surface at lower left, abaxial surface on right, portion of cataphylls intact, stem with fibrous cataphylls and young cataphylls on upper end of stem.

FIGURE 3. Anthurium rosselianum. Holotype specimen: MO-4940581, sheet 3. Colombia. Cauca: Along road between Popayán and Juntas via Viente de Julio Popayán, 17 km W of summit, 1280 m, 2º31’18”N, 77º 01’56”W, 19 July 2007, T.B. Croat & J.F. Gaskin 80112. A portion of leaf blade, posterior lobe outer margin with overlay, stem, petiole and cataphyll with stem, inflorescence and petiole.

FIGURE 4. Anthurium rosselianum. Holotype specimen: MO-4940582, sheet 4. Colombia. Cauca: Along road between Popayán and Juntas via Viente de Julio Popayán, 17 km W of summit, 1280 m, 2º31’18”N, 77º 01’56”W, 19 July 2007, T.B. Croat & J.F. Gaskin 80112. Removed cataphyll and inflorescence with old peduncle and spathe and new spadix in lower center and upper center without spathe.