Notes on Elaeagia myriantha, Comb. Nov. (Rubiaceae)

Abstract

Observations of recent fruiting collections of Simira (Standley) Steyermark, a tree found in wet mid-elevation forests from southern Costa Rica to Peru, support the following transfer of this species to Elaeagia. Sickingia Standley was originally described from flowering material from northern Colombia, but Standley himself later erected the monotypic genus to accommodate this species, as (Standley) Standley. Even though classification within the Rubiaceae has been strongly dependent on knowledge of mature fruits, which were lacking for this taxon, Standley (1938) placed in the Rondeletieae along with Sickingia Willdenow. Steyermark (1972) determined that Sickingia is a synonym of Simira Aublet and published new combinations in Simira for all Sickingia species, including Sickingia myriantha. In that work he considered the placement of this species in Elaeagia, but rejected this conclusion based on its corolla aestivation. He stated only that the aestivation differed, but did not describe its condition. Steyermark (1974) later presented a detailed description of this species, although the mature fruits were still unknown and his description of them was sketchy. Recent botanical exploration, particularly in Colombia, has made more material of this species available, including mature fruiting specimens. The fruits are small (2-3 mm long), loculicidal woody capsules that dehisce only partially, apparently allowing a salt-shaker dispersal of the numerous small angled seeds. The fruits and seeds are decidedly not those of Simira, which has larger (> 1 cm diam.), completely dehiscent capsules with broad, flat, samaralike seeds. Rather, they are characteristic of Elaeagia Weddell and Warszewiczia Klotzsch, sympatric genera of neotropical trees. These genera are distinguished in part by their corolla aestivation, convolute in Elaeagia and imbricate in Warszewiczia. Aestivation of the species in question is nearly valvate to slightly convolute, more like that of Elaeagia, rather than imbricate as originally implied by Standley when he described this species in Sickingia. also shares with Elaeagia species rounded to truncate stipules (vs. acute in WarszewNOVON 3: 490-491. 1993. iczia), resinous terminal buds (vs. nonresinous in Warszewiczia), glomerulate cymes arranged in pyramidal paniculate inflorescences, and white, short tubular-funnelform corollas with exserted stamens that are barbate near their insertion (similar in Warszewiczia). Thus, because of its fruits Holtonia myriantha is not a Simira but rather an Elaeagia, and a slight variation in corolla aestivation does not warrant maintaining as a separate genus. We present below an expanded morphological description and geographic range for this species, and a selected list of specimens, in addition to types, on which these are based. Representative specimens from Venezuela were cited by Steyermark (1974). This species is distinguished within Elaeagia by its persistent, relatively short rounded to truncate stipules. It appears to be most closely related to E. cubensis Britton, which shares membranaceous, relatively short stipules that persist on several distal nodes. However, the stipules of E. cubensis are ultimately completely deciduous and shorter, and the corolla is campanulate. Elaeagia Weddell, Hist. Nat. Quinquinas 24. 1849. TYPE: Elaeagia utilis Weddell. Standley, Trop. Woods 30: 37. 1932, syn. nov. TYPE: (Standley) Standley, based on Sickingia Standley. Elaeagia (Standley) C. M. Taylor & Hammel, comb. nov. Basionym: Sickingia Standley, Publ. Field Columbian Mus., Bot. Ser. 7(1): 27. 1930. (Standley) Standley, Trop. Woods 30: 37. 1932. Simira (Standley) Steyermark, Mem. New York Bot. Gard. 23: 306. 1972. TYPE: Colombia. Magdalena: Las Nubes road, region of Santa Marta, 1,200 m, 3 Dec. 1898, H. H. Smith 1810 (holotype, F; isotypes, MO, NY not seen, US not seen). Deppea panamensis Dwyer, Ann. Missouri Bot. Gard. 67: 145. 1980, syn. nov. TYPE: Panama. Panama: 5-10 km NE of Altos de Pacora, Mori & Kallunki 4965 (holotype, MO). Trees to 20 m tall, buds resinous; bark gray, rough; stems pilosulous to glabrescent. Leaves opThis content downloaded from 157.55.39.211 on Tue, 27 Sep 2016 03:59:56 UTC All use subject to http://about.jstor.org/terms Taylor & Hammel Elaeagia posite, elliptic, 8-22 cm long, 2.5-10 cm wide, acute at base, acute to shortly acuminate at apex, chartaceous to stiffly so, glabrous above, below glabrous to puberulent or pilosulous, frequently barbate with tufted domatia in vein axils; secondary veins 8-12 pairs; petioles 7-25 mm long; stipules persistent, interand intrapetiolar, resinous when young, glabrous to pilosulous, 2-5 mm long, subtruncate to lobed for ca. /3 of their length, not splitting to base, lobes rounded to obtuse. Inflorescences terminal, paniculate, pyramidal, peduncles 0 (and inflorescences tripartite) to 1-7 cm long, panicles 611 cm long, 7-14 cm wide, bracts triangular, those subtending branches 1-3 mm long and those subtending flowers ca. 0.5 mm long, branches and bracts glabrous to pilosulous; flowers sessile or with pedicels to 1 mm long in glomerules of 2-8, homostylous, proterogynous; ovary turbinate, 1-1.5 mm long; calyx limb ca. 0.5 mm long, dentate for ca. 2 of its length, lobes 5, acute to obtuse; corolla shortly tubular-funnelform, white to creamy yellow, glabrous externally, internally densely white-villous, tube 3.5-4 mm long, lobes 5, ca. 0.5 mm long, acute to obtuse, aestivation valvate to slightly convolute; stamens 5, inserted near apex of corolla tube, the anthers ca. 1.5 mm long, exserted by ca. 1 mm; stigmas 2, 1-1.5 mm long, linear, recurved, shortly exserted. Fruit capsular, ellipsoid to turbinate, woody, 2-3 mm long, 1.5-2.5 mm wide, loculicidal, basipetally dehiscent, opening for ca. '/ of its length; seeds angled, pale brown, 0.2-0.5 mm diam. Distribution and habitat. Wet forests at (400-)1,600-2,200(-2,350) m, southern Costa Rica to Andean Venezuela and northern Peru, most frequently collected in northern and central Colombia. Phenology. Collected in flower January, March, April, and September to November, in fruit March, April, June, July, and October to December. Representative specimens studied. COLOMBIA. Antioquia: autopista Medillin-Bogota, sector rio Samanario Claro, San Luis, Herndndez et al. 522 (COL). Cauca: Popayan, Timbio en Hatoviejo, Perez & Cuatrecasas 6107 (COL). Magdalena: Campano, Sierra Nevada de Santa Marta, Minca, 11?08'N, 74?01'W, Gentry & Cuadros 64762 (MO). Quindio: municipio Salento, vereda rio Arriba, Hacienda El Cairo, Arbelaez et al. 2563 (COL, HUQ). Valle: hoya del rio Cali, rio Pichind6, en Los Carpatos, Cuatrecasas 21625 (CUVC, VALLE). COSTA RICA. Puntarenas: Reserva Biologica Carara, sitio Bijagual, Ziuniga 407 (CR). San Jose: Zona Protectora Cerro Turrubares, Hammel et al. 18967 (CR); El General, Skutch 2387 (MO). ECUADOR. Napo: carretera Hollin-Loreto, Km 40-50, Hurtado 777 (MO). Pastaza: Hacienda San Antonio de Baron von Humboldt, 2 km al norte de Mera, 1?27'S, 78006'W, Neill et al. 6069 (MO). PERU. Cusco: Paucartambo, Atalaya a Chontachaca, alrededor de la carretera en la ruta hacia Shintuya, Nfniez 8074 (MO). Acknowledgments. This work was stimulated by preparation for the Flora Costaricensis and the Manual of the Plants of Costa Rica, and was supported in part by National Science Foundation grant BSR-9006449. We thank the Asociacion Colombiana de Herbarios for making available Colombian collections of this species, and David Lorence for valuable comments.