Puya serranoensis Rauh[as Puya serranoensis Rauh]

Diagnose: —Planta acaulis, solitaria, florens usque ad 50 cm alta; folia numerosa rosulam usque ad 30 cm altam et 50 cm diametientem formantia; vaginae distincte limitatae, rotundiusculae, 3-3,5 cm latae, 2,5-3 cm longae, castaneae, supra detergibili - tomentosae, omnino pseudobulbum usque ad 6 cm diametientem formantes; laminae usque ad 50 cm longae anguste lineares, supra vaginam 8-12 mm latae, in apicem longum filiformem recurvatum excurrentes, subtus albido-cano-¬tomentosae, supra subglabrae, virides, margine minutis aculeis uncinatis brunneis 6-15 mm inter se distantibus; apices foliorum mox desiccantes; scapus inflorescentiae 15-20 cm longus, 8 mm diametiens, virescenti-rufescens, tomentoso-lepidotus; phylla scapi: basalia subfoliata, vagina brevi, albo-lepidota margine minutissime aculeato et lamina filiformi, superiora acuminata elaminata; inflorescentia plus minusve 30 cm longa, 8 cm lata, laxe bipinnata, plus minusque spicis lateralibus breviter stipitatis 4,5-9 cm longis 3-12 floris adscendentibus; rhachis tenuis recta, rufescens albo-floccoso-lepidota; bracteae primariae, 2,7-3,5 cm longae ovali-lanceolatae, acumi¬natae, modice inflatae margine denticulatae, spicis multo breviores; bracteae florales bracteis primariis superioribus similes, ventricoso-inflatae, ecarinatae, ovales, breviter acuminatae, roseae, albo-lepidotae, pedunculos 6-7 mm longos superantes ; flores heteromalli, plus minusve erecti, sine pedunculo 18-20 mm longi virescenti-rosei; sepala 1 cm longa, 5-6 mm lata, acuminata, posteriora indistincte carinata, rosea, albo-floccoso-lepidota; petala 16 mm longa, 11 mm lata, apicibus parum recurvatis metallice obscuro-smaragdinis; stamina et stylus petalis breviora; filamenta alba, 14 mm longa antheris 3 mm longis luteis; ovarium 7 mm altum semisuperum; stylus cum stigmate staminibus breviore. Flores post anthesin parum torti. Habitat et distributio: Bolivia, inter Villa Serrano et Rio Grande, 2200 m.s.m. in declivibus saxoso-graminosis. Holotypus: HROMADNIK 5230 (= B.G.H. 50 831) in herb. Inst. bot. system. univ. heidelber¬gensi.

Observations: —Puya serranoensis collected by H. HROMADNIK as a Deuterocohnia , however it is of the subgenus Puyopsis (Inflorescence axis visible). Referring to the Puya key by L. B. SMITH in (Subkey, I, p. 67) in Flora Neotropica, Pitcairnioideae, we find the following characteristics: Inflorescence compound; branches of the inflorescence “more than twice as long as the sheaths of the primary bracts”; one assumes however, that the “branches of the inflorescences not more than twice as long as the primary bracts " applies (this is however not the case with the present plant), so one refers to couplet 53 according to the width of the leaf blade (10-75 mm or 2-10 mm) to reach either P.assurgens L. B. SMITH (leaf blade 10-75 mm wide) or to P. tuberosa Mez ( leaf blade 2-10 mm wide). With P. serranoensis the blade directly above the sheath is 12 mm wide at most, the remaining blade is narrower. P. assurgens differs from P. serranoensis in the following characteristics: at the base no bulb like swelling; the to 18 mm wide leaves have an underneath covered with appressed not hairy long scales; the Inflorescence is dense bipinnate with to 6 cm long, ascending side spikes and few flowered; the basal floral bracts should exceed the edge of the fine serrated sepals, the petals are green and postfloral shiny dark purple.
All these characteristics do not apply to Puya serranoensis where the leaf blade is narrow-linear, less than 10 mm wide; the Inflorescence is lax bipinnate; the primary bracts are relatively small; the sepals have entire edges; the petals at anthesis and postfloral are dark bluish green. Moreover, the type locality for P. assurgens is declared as Argentina (Jujuy) and not Bolivia.

With Puya tuberosa Mez, the bulb-like base is admittedly right, but only to 3 cm in diameter with thick offsets at the base, however the foliage leaves are the same as P. tuberosa, thin filamentous (after observations of the type specimen by Haenke s., N., Bot. State-collection Munich), the inflorescence is simple or only sparingly branched, with (1-2) short, about 3 cm long, few flowered side spikes. Inflorescence axis, scape bracts, primary bracts, and floral bracts, are like the sepals virtually glabrous in age. The petals are blue-violet, drying off wine-red.

Puya serranoensis is also related to P. vallo-grandensis: but differs from this through the formation of bulbose single rosettes, through the less strongly branched inflorescence, the very lax, not intensively carmine red coloured side spikes, as well as not through the postfloral in folded sepals.
Collectively all narrow leaved dwarf Puya species, P. minima, the very similar P. hromadnikii, P. tuberosa, P. serranoensis, P. vallo-grandensis, and maybe also P. assurgens and P. dyckioides (Baker) Mez, form a single complex in Bolivia. To clarify this question, further examinations are needed especially since other narrow leaved dwarf forms were found also in North-Peru, whose inflorescence and flowers are not known to Pang.

Translated by Butcher from: Rauh 1983a. (protologue) Bromelienstudien (Mitteilung 12). I. Neue und wenig bekannte Arten aus Peru und anderen Ländern .