Puya pumila Ravenna[as Puya pumila P Ravenna]

Diagnose: —Planta multiceps, congesta, 70-80 cm alta, inferne radicibus pluribus emitens. Folia rosulata, lineari-angustata, recurve patentia et erecto-patentia, ad margines spinosa, facie adaxiali opace viridia, abaxiali dense minuteque lepidote-tomentulosa, tomentulis cinereo-argenteis, 28-13 cm longa et 10-4 mm lata, spinis uncinatis et retrorsis, carti¬lagineis, sed apice duro pungentique, 3-1.3 mm longis. Caulis floriferus cylindricus, robustus, usque basin inflorescentiae 50-58 cm longus et 15-18 mm crassus, inferne foliis abbreviatis deinde bracteis ovato-lanceolatis, ventricosis, purpurescentibus, deciduis, facie abaxiali tomentulosa, tomentulis cinereis, internodiis viridibus et purpureo-castaneis. Inflorescentia ramosa, thyrsoidea. Rami 7-10, subpatentes, usque duos tertios floriferi, demum apicem versus steriles, sensim angustati, bracteis lanceolatis vel ovato-lanceolatis, purpureis, 30-4 mm longi. Axis centralis inflores¬centiae ad tres quartos inferiores lepidote-tomentulosus, tomentulis albicantibus. Pedicelli virides 6-7 mm longi. Receptaculum truncate obovatum, viridis, 3-5 mm longus. Sepala lanceolato-naviculata, ad coroliam adpressa et cingentia, ad medium inferiorem inter se imbricata. 23-27 mm longa et 7-10 mm lata, sparse tomentulosa vet subglabra, acute vel obtuse cuspidata. Corolla anguste campanulata, post anthesin spiraliter tortila; tepala coerulea vel interdum facie abaxiali coerulea et viridia, 45-47 mm longa et 15-18 mm lata. Filamenta leviter declinata, filiformi-subulata, azurea sed basin versus albicantia, sepalina 27-31, petalina 30-34 mm longa. Antherae subbasifixae oblongae, aurantiacae 3.8-4 mm longae, pollen loculique aurantiaci. Ovarium ovatum, trigonum, albo-viridescens, ad 6 mm longum et 4.6 mm latum. Stylus subrectus, azureus, 27-30 mm longus, apice trifurcato, ramis 2,4 mm longis, inter se flexuose arcteque adpressis, ad apicem crispate glanduloso-stigmatosis, stigmatum capitato simu¬lantibus.

Observations: —Puya pumila is a monocarpic plant. In general design, it resembles Puya alpestris (Poepp, et Endl.) Gay (1853), P. berteroana Mez (as "berteroniana", see Stuessy & Marticorena 1991), and P. chilensis Mol., three species that usually inhabit abrupt places, on or among rocks. From the former to which it is closely related, it departs in the smaller habit, shorter and narrower leaves, purple-tinged bracts, and shorter, tightly appressed style arms, which simulate a single capitate stigma at the apex, (see key below); from the others, in the much lower habit, and in being smaller in all its parts. Actually, the latter two species exceed 2 m high, and bear coarse leaves that reach 1 m in length, and 35-40 mm in breadth at the blade base. In P. chilensis leaves are entirely glabrous, and dull green. Puya berteroana, may display either blue, or green corollas (inedit inf.), and adaxial face of leaves is sparsely lepidote-tomentulose gradually downwards from its half, and the abaxial quite densely and silvery, lepidote-¬tomentulose. In this species spines are hard, 7-3 mm long, brown and sclerified nearly to the base.

Ruiz and Pavon (1798), founded the genus Pourretia, with P. coarctata Ruiz et Pav. as type. The name was antedated by Puya Molina (1782), and the species apparently is a synonym of P. chilensis Mol.

Poeppig and Endlicher (1838), described Pourretia alpestris, from the mountains of Antuco in southern Chile. Actually, Poeppig collected the plant at the top of mount Pilque. The species was transferred to Puya by Mez (loc. cit.).

Hooker fil. (1865), described, and illustrated a supposedly new species, namely P. whiteii. This proved to be a further synonym of P. berteroana (ined. inf.).

Philippi (1894) discussed the nomenclature, and synonymy of Puya chilensis. and P. whyteii Hooker fil., and considered that the proper name for the latter should be P. coerulea Miers ex Lindl., which obviously is a mistake. The latter is a valid species of subgenus Chagualia.

In their monograph of the genus Puya in Chile, Smith & Looser (1935). structured the genus into three subgenera. Eupuya Mez (= Puya), Chagualia Sm. & Loos., and Pourretia (Ruiz et Pav.) Mez (loc. cit.). Subgenus Puya, to which P. pumila belongs, is featured by a thyrsoid or oblong inflorescence, in which patent or subpatent branches are gradually narrowed, and sterile in the upper half or third. Additionaly, petals show entire edges down to the base, without any callose protuberance, the latter being a dist¬inctive feature of subgenus Chagualia. These authors considered P. berteroana a synonym of P. alpestris. Since Pourretia is a synonym of Puya, it cannot be used for another subgenus.

Worth of mention is a paper by Varadarajan (1990), in which chorology patterns of Puya species are surveyed in connection to the philogeny of the group.

Some recently proposed Chilean species, are P. quillotana W. Weber (1984), and P. gilmartinii Varadajan & Flores. The former may be synonym either of P berteroana, or P. chilensis (see comments below), and the latter apparently is the same plant previously identified by Flores (1981), as P. coquimbensis Mez. Ziska (1992: 102), refers to Varadarajan and Flores opinion, that P. gilmartinii " possibly is of hybrid origin, and it is much similar both to P. chilensis, and P. boliviensis". A photograph from the type of P. coquimbensis Mez (Gaudichaud 53, P), shows an inflorescence culm which seems to match in P. venusta Phil. If this proves to be true, the latter should become a synonym of the former. By the way, Zizka (loc. cit.), refers erroneously to P. alpestris, as inhabiting Central Chile.

P. berteroana was originally collected "prope Quillota and La Quinta" (Bertero 115, P). Curiously enough, Mez (loc. cit.), describes it as "inflorescentia ample paniculata, ramulis apicem versus fertilibus". These characters would exclude it from subgenus Puya. Nonetheless, Prof. Benoist, of the Paris Museum, examined the type-specimen, under request of Smith & Looser (loc. cit.: 262), and verified that the young inflorescence branch, though shortly, actually is sterile at the apex. Thus the species belongs in subgenus Puya. The reference to blue flowers exclude it from P. chilensis, and the name is therefore associated to the well known blue- (or green-) flowered plant of the area. Both species grow together near Limache (_ "La Quinta").

To subgenus Puya also belongs the magnificent Puya raimondii Harms, from the highlands of Bolivia and Peru, which reaches 8 m or more in hight. Two additional species of this group, are P. fiebrigii Mez, and P. hofstenii Mez, the former from Bolivia, and the latter from northern Argentina. Both of them display lax, open inflores¬cences.

KEY TO SPECIES OF SUBGENUS PUYA IN CHILE
A. corolla yellow or greenish yellow.
B. Leaves totally glabrous, almost straight, mostly erecto-patent. Plants 2-3 m high. Coastal slopes, and coastal belt of C zone, and near north. 1. P. chilensis Mol.

BB. Leaves lepidote-tomentulose on the abaxial face, recurvely patent. Plants 1¬1.50 m high.

C. Leaves ferrugineous, with white spines. Coastal slopes in the near north.
2. P. gilmartinii Varad. & Flores

CC. Leaves green, at least on the adaxial face, spines brown. Coastal slopes in the far north.
3. P. boliviensis (Bak.) Mez

AA. Corolla electric blue, or sometimes green (in species 4).

B. Plant 2-2.50 m high. Leaves to 1 m long. 25-30 mm broad at the blade base: Inflorescence branches 20-25. C Chile, lower Andean slopes, and coastal belt. 4. P. berteroana Mez.

BB. Plant 0.7-1 m high. Leaves 30-13 cm long. Inflorescence branches 7-10.

C. Style branches 2.4 mm long, flexuose, and tightly folded up, simulating a single capitate stigma at the body apex. Leaf spines cartilagineous. 3-1.3 mm long, sclerified part brown on the upper half or solely at the apex SW of central zone.
5. P. pumila Rav.

CC. Style branches 3-4 mm long, apparently free from each other. Leaf spines hard, dark, 6-2 mm long, sclerified from base to top. South Chile. 6. P. alpestris (Poepp. et Endl.) Gay

COMMENTS
Smith & Looser (loc. cit.: 247), referring to P. chilensis, and P. boliviensis, say. "hojas pronto glabras en ambas caras", meaning the supposed existence of indument in young leaves. In the former species, at least, this statement reveals itself as incorrect, since ab initio both leaf faces are entirely glabrous. P. quillotana W. Weber (1984). described from a scanty specimen, collected near Quillota, most probably, as said before, is a synonym either of P. chilensis or P. berteroana. The latter two species are the only ones, often growing together, that are found in the whole area.

Edited from : Ravenna 2000. (protologue) A new Puya Species from Central Chile .