Romanschulzia mexicana is described as new and illustrated. It is readily distinguished from all other 12 species of Romanschulzia by its fruiting pedicels and gynophores that are both very long and rather slender. Romanschulzia 0. E. Schulz is one of two genera of the Brassicaceae (Cruciferae) that are distributed exclusively at high altitudes in the tropics (Al-Shehbaz, 1984). The other genus is the African Oreophyton 0. E. Schulz. Romanschulzia consists of 12 species distributed from central Mexico south into Panama at 1,800-3,300 m (Rollins, 1942, 1956, 1984). The genus belongs to the Thelypodieae Prantl, a tribe considered by some to include genera that appear to be primitive among the Brassicaceae (Cruciferae) (Al-Shehbaz, 1973, 1985; Rollins, 1956). Because of its exceptionally long gynophores and shrubby habit, the new species was thought to be a member of the Capparaceae and thus was sent to one of us (H. H. Iltis). Iltis identified it as an unknown Romanschulzia because of its long gynophore, as well as the presence of a complete septum and incumbent cotyledons not invaginated between the radicle and cotyledons; the latter both are characters typical of Brassicaceae and not Capparaceae-Cleomoideae. Although the single collection on which R. mexicana is based contains no flowers, the species is described because of its unique fruiting material. Romanschulzia mexicana Iltis & Al-Shehbaz, sp. nov. TYPE: Mexico. Guerrero: Mun. Leonardo Bravo, Pedregal, 28 km by road WSW of Filo de Caballo, 10 June 1985, W. Thomas & J. L. Contreras 3788 (holotype, NY; isotype, WIS; fragments, MEXU, UC). Figure 1. Frutex scandens usque ad 2.5 m; folia petiolata lanceolata vel oblongo-lanceolata obscure denticulata, folia proxime infra racemos auriculata vel amplexicauli; pedNOVON 3: 96-98. 1993. icelli fructiferi tenuississimi, arcuati vel divaricati, 4-8 cm longi; gynophoro tenuississimo, 2-3.2 cm longo; fructus cylindricus, 2.5-4.1 cm longus; semina oblonga, uniseriata, 2.6-3.6 x 1-1.3 mm; cotyledones incumbentes. Scandent shrubs to 2.5 m, glabrous throughout. Stems terete, green when young, becoming straw colored with age; lateral branches 3-10 cm long; pith solid. Lowermost leaves of lateral branches petiolate, lanceolate to oblong-lanceolate, 2.5-6 x 0.42.2 cm, cuneate at base, obscurely denticulate, acute at apex; leaves just below racemes sessile, auriculate to amplexicaul, with rounded to subacute basal lobes. Flowers not seen. Infructescences lax racemes, 37 cm long, terminating lateral branches; fruiting pedicels very slender, divaricate at base, strongly arcuate to straight, 4-8 cm long, 0.3 mm diam. Receptacle 1.2-2 mm diam.; nectar glands continuous, subtending bases of all filaments. Gynophore very slender, 2-3.2 cm long, ca. 0.3 mm wide, obscurely and longitudinally 4-striate or 4-winged. Fruit narrowly cylindrical, 2.5-4.1 cm long, 2-3 mm wide; valves acute at both ends, with a prominent midvein and conspicuously reticulate lateral veins; septum complete, thin, opaque, pushed to valves by seeds on other side; style absent; stigma entire, minute. Seeds narrowly oblong, brown, 2.63.6 x 1-1.3 mm, plump, uniseriately arranged in each locule, wingless, faintly and minutely reticulate, with a tiny appendage distally; cotyledons incumbent, that facing radicle smaller. Distribution. Known only from the type material, collected in forests and pasture on karstic limestone at 1,800-1,900 m. The relationship of Romanschulzia mexicana is not entirely clear. The shrubby habit in Romanschulzia is known only in another species, R. apetala Rollins, which is a narrow endemic of the Cordillera Talamanca, Prov. Cartago, Costa Rica, once collected by R. W. Holm and H. H. Iltis in 1949 (Holm & Iltis 536, MO). However, the latter, only This content downloaded from 157.55.39.32 on Mon, 10 Oct 2016 04:17:55 UTC All use subject to http://about.jstor.org/terms Volume 3, Number 2 1993 AI-Shehbaz & lltis Romanschulzia mexicana