Dyckia rupestris W.Till & Morawetz[as Dyckia rupestris W. Till & W. Morawetz]

Diagnose: —A D. oligantha L. B. SMITH, cui affinis, characteri¬bus sequentibus differt: planta majora, florens usque ad 55 cm alta; folia longiora, vaginis longioribus (us¬que ad 34 mm longis); inflorescentia (8-) 11-18-flora, (10-) 13-17 cm longa; rhachis inflorescentiae recta; internodia media scapi 17-24 mm longa; bracteae florigerae carinatae, usque ad 12 mm longae, angu¬sto-triangulares, basem versus margine denticula¬tae, supra mediam integrae; flores erecto-patentes, minores, 11-12 x C-7 mm metientes; pedicelli (3-) 4-7 mm longi, ± cylindrici, subtenues, bracteis flori¬geris quartum pattern breviores usque ad aequilongi; sepala apiculata; petala rhomboidea, angustiora, 12 x 8,5 mm metientia; filamenta latiora, crassiora, an¬therae cylindricae, non triangulares. Typus: W. Morawetz 13-201285, Brasilia, Pernam¬buco septentrionalis, apud civitatem Brejo da Madre de Deus (occidentali-septentrionalis de civitate Ca¬ruaru), 20.12.1985 (holotypus R!, isotypus WU!). Patria: Adhuc nota solum loco classico.

Observations: —Using the Key of Smith & Downs (1974) you come to D. oligantha, from which D. rupestris differs in vegetative and floral characteristics (Fig. 1) as in the differential-diagnosis afore mentioned. Can also be compared with D. duckei L. B. Smith and D.biflora Mez , from which main differences are the scales on the inflorescence, the acuminate and partially entire edged floral bracts, the more rugged growth, longer leaves and the geographic spread. It differs from D. sordida Baker in the colour of the scales on the inflorescence, the finely toothed upper scape bracts and floral bracts, the clearly stemmed flowers and in the geographic spread. Lastly is the strong endemism of many species of this genus in the broader sense.

From the two known dyckias from Pernambuco - one of which was also found in Brejo da Madre de Deus in Brejo - the new species differs from D. pernambucana L. B. Smith by clearly shorter leaves and much smaller rosettes, the pale leaf-sheaths, the always glabrous upper side of the leaf, the slimmer scape, the non leaf like lower scape bracts, the always simple inflorescence, that is only 17 cm long , the longer ( to 12mm) floral bracts, the to 7 m long pedicel, the second flowers, the pointed, wider and shorter sepals and the less strongly joined filament;
From D. limae L. B. Smith it differs by the shorter leaves and smaller rosettes, the almost entire edged leaf sheaths, the glabrous upper side of the leaf, the scaled scape, the always simple and shorter inflorescence, the straight Rhachis, the longer (to 12mm) floral bract, longer and slimmer pedicel and the short joined filament.

Rauh has recently described 4 new taxa from the D. oligantha group (Tropische und subtropische Pflanzenwelt no. 60, 1987 and no. 65, May 1989.) D. oligantha var. cristallina Rauh is a typical variety distinguished from D. rupestris. D. nervata Rauh is much smaller than D. rupestris, it has strongly bent over leaves, a strong woolly inflorescence, bent down-wards floral bract, shorter sepals and petals and higher joined filaments
D.brachystachia Rauh & E. Gross is also much smaller and through the poor flowering, small inflorescence, the seeming permanently closed flowers and the very high joining of the filaments. It is largely similar to D. granmogulensis Rauh from the federal state of Minas Gerais, from which D. rupestris can be distinguished by the clearly larger leaf sheath, brown leaf spines, upper side glabrous blades, the strongly scaled scape, the somewhat less flowered , to the top of the fertile inflorescence, the clearly larger flowers, the tip felt like and not woolly, larger sepals and the clearly larger petals.

Edited from : Till & Morawetz 1990. (protologue) Eine neue Dyckia aus Pernambuco, Brasilien: Dyckia rupestris W. Till & W. Morawetz, spec. nov. .