BONPLANDIA 16(1-2): 143-180 2007 STERCULIACEAE OF PARAGUAY II WALTHERIA JANICE G SAUNDERS1 Summary: Saunders, J G 2007 Sterculiaceae of Paraguay II Waltheria Bonplandia 16(1- 2): 143-180 ISSN: 0524-0476 The biodiversity and geographical distribution for Waltheria species in Paraguay are presented to accompany the floristic treatment for the rest of the family given separately in Part I (Cristóbal, 2007) In this work eight species are accepted, described, illustrated, mapped, and a key is given to facilitate their identification Waltheria operculata belongs to sect Stegowaltheria, and the others are from sect Waltheria: W albicans, W carmensarae, W communis, W indica s l , W macrophylla, W procumbens, and W viscosissima Two species are endemic to Paraguay: W procumbens, restricted in distribution, and W macrophylla, collected only once and possibly extinct; both species are in need of local conservation assessment fieldwork Key words: possibly extinct species, section Stegowaltheria, section Waltheria, homostyly, heterostyly, America Resumen: Saunders, J G 2007 Sterculiaceae de Paraguay II Waltheria Bonplandia 16(1- 2): 143-180 ISSN: 0524-0476 Se presentan la bíodiversidad y distribución geográfica de Waltheria en Paraguay, que complementa el tratamiento floristico de la familia Parte I (Cristóbal, 2007) En este trabajo se aceptan 8 especies que son descriptas e ilustradas y se acompañan mapas de distribución y una clave para su identificación Waltheria operculata pertenece a la secc Stegowaltheria, y las otras a la secc Waltheria: W albicans, W carmensarae, W communis, W indica s l , W macrophylla, W procumbens, and W viscosissima Puede señalarse que existen dos espe- cies endémicas en Paraguay: W procumbens de distribucion restringida y W macrophylla, coleccionada sólo una vez y posiblemente extinguida Para ambas especies se sugieren tareas locales tendientes a su localización y conservación Palabras clave: especies posiblemente extinguida, sección Stegowaltheria, sección Waltheria, heterostilia, homostilia, América Waltheria L Sitella L H Bailey, Gentes Herb 4(9): 349 figs 222-223 1940 Linné, C, Sp Pl: 673 1753 Lophanthus J R Forst & G Forst, Char Gen Shrubs, shrublets, suffrutescent herbs, Pl: 27, t 14 1776 vines, herbs, unarmed, erect to prostrate Astropus Spreng, Neue Entdeck 3: 64 1822 Vestiture of stellate, simple, and glandular 1 Instituto de Botánica Darwinion, Casilla de Correo 22, B1642HYD San Isidro, Argentina E-mail: jsaunders@darwineduar 143 BONPLANDIA 16(1-2) 2007 hairs; glands sessile or capitate Leaves 35, 40) mm x 10-22(-27) mm; dehiscence stipulate, petiolate; laminas serrate, crenate, usually partially loculicidal, rarely bivalvate or dentate Inflorescences distal or disperse, or operculate Seed 14-25(-27, 30) mm x pedunculate or sessile, glomerulate, 10-15(-20) mm, more or less obovoid, composite or secund, compound cymose or obconical, at times obpyramidal and laterally with compound cincinni; primary cymes often 3-faced with sides curved, but not trigonal consisting of 4 bracts2 (these unequal or Embryo straight; cotyledons flat, equal) per floral pair, or 5-bracteate, or 3- suborbicular, cordiform, oblate; endosperm flowered Flowers sessile, rarely short- present pedicellate, perfect, distylous or homostylous Sepals 5, campanulate or tubular, 5-dentate, 5- A tropical and subtropical genus with ca lobed or 5-parted Petals 5, yellow, flat, 60 species, 53 of them American, and one basally clawed; claw adherent basally to species distributed worldwide Six species are staminal tube very slightly, essentially free, extra-American from either NW Australia, or up to one third of petal length (for 02-3 mm) Asia (both Hainan and Malyasia), or Androgynophore absent or reduced, minute Madagascar, or W Africa, or Maui (Hawaii), (07 mm) Stamens 5, opposite petals; or from both the Islas Marquesas and the filaments connate variously for basal third, Society Islands Phylogenetically these extra- halfway, mostly or throughout forming a American species appear to be scattered staminal tube, rarely essentially free; anthers throughout the genus (Saunders, 1993, 1995) 5, fertile, extrorse; thecae 2, parallel, oblong, Waltheria possesses two centers of diversity longitudinally dehiscent Staminodes absent and endemism: the largest in Brazil, a second or rarely present, vestigial, minute, and in Mexico In Paraguay, eight species occur denticulate Pistil 1 Stigma 1, elongate- One of the two endemics, W macrophylla, plumose (column elongate with branches may possibly be extinct Seven of the short), penicillate, (column null, branches Paraguayan species belong to sect Waltheria long, to 15 mm long), or capitate-penicillate One, W operculata Rose, belongs to sect (branches very short, 05 mm long) Style 1, Stegowaltheria K Schum (Schumann, 1886), lateral or eccentric Ovary 1; locule 1; ovules a group with the following synapomorphic 2 (1 abortive) Capsule usually shed together characters: operculate capsule dehiscence, with calyx, with 1 carpel, with 1 seed Capsule subcordiform foliose stipules, and verrucose, with calyx surrounding, with apex free, 2-32(- tuberculate seed testa (Saunders, 1995) Key to the species of Waltheria in Paraguay 1 Stipules filiform, flexuose, rarely firm and linear-triangular; capsule bivalvate, the 2 valves separating completely 1 W communis A St-Hil 1' Stipules narrowly triangular, triangular, linear-triangular or subovate, never flexuose; capsule not bivalvate 2 Petioles 26-5 mm wide; larger leaves 10-18 cm wide 2 W macrophylla Hassl 2' Petioles < 20 mm wide, or rarely 25 mm wide; larger leaves 1-75(10) cm wide 3 Stems without stellate trichomes, strigose with simple trichomes to 25 mm long; capsule dehiscence operculate 3 W operculata Rose 2 Subsequent bracts described belonging to the primary cyme of floral pair 144 J G Saunders, Sterculiaceae de Paraguay II 3' Stems predominantly with stellate trichomes or glandular-capitate trichomes; capsule dehiscence partially loculicidal, open at apex and upper sides only 4 Leaves acuminate or rarely acute at apices 4 W viscosissima ASt Hil 4' Leaves rounded, obtuse or acute at apices 5 Plants prostrate or procumbent 6 Stems to 04 m long, stiff; flowers distylous; leaves glabrescent, often with black spots or black maculae 5 W procumbens JG Saunders & Soria 6' Stems 06-1 m long, very flexuose; flowers homostylous; adaxial surface of leaves tomentulose, red-spotted below trichomes 6 W carmensarae JG Saunders 5' Plants erect or mostly decumbent, or long lower stems decumbent 7 Capsule interior with endocarp thinly horny (corneous) apically only, for only 04-1 mm in length from apex; petals showy, 48-9 mm x (1)15-38(45) mm; petal lamina obdeltate or obtriangular, subglabrous; petal apical margin truncate with a few simple or V-shaped hairs; claw adherent to basal staminal tube for 07-12(16) mm 7 W albicans Turcz 7' Capsule interior with endocarp thinly to thickly horny (corneous) for half to most of the capsule length from the apex, for ca 08-25 mm; petals small, 3-4(-47) mm x 05-12 mm; petal lamina obovate, elliptic, oblong, rarely obtriangular; petal apical margin usually rounded or obtuse, rarely truncate, vestiture variable, glabrous to densely stellate; lamina adaxial surface vestiture variable, glabrous throughout, or hirsute on distal portion; lamina abaxial surface glabrous to densely stellate on nerves; claw adherent to stamen tube base for 02-08 mm 8 W indica L sl 1 Waltheria communis ASt-Hil Waltheria douradinha A St-Hil, Pl Us Bras 8, Figs 1, 2 and 3 pl 36 1825, syn nov Waltheria boliviensis Turcz, Bull Soc Imp Naturalistes Moscou 36(1): 571 1863, syn nov Saint Hilaire, A, Fl Bras merid 1: 155 1825 Waltheria communis var tomentella K Schum, Waltheria communis var vulgaris (St Hil sic, in Mart, Fl bras 12(3): 59 1886, syn nov sensu K Schum) K Schum, nom illeg Waltheria communis var platyphylla K Waltheria lanata A St-Hil, Fl Bras merid 1: Schum, in Mart, Fl bras 12(3): 59 1886, syn nov 154 1825 Waltheria communis var henningsii K Schum, Waltheria communis var lanata (A St-Hil) K in Mart, Fl bras 12(3): 59 1886, syn nov Schum, in Mart, Fl bras 12(3): 58 1886, syn nov Waltheria communis var dietrichii K Schum, Waltheria gracilis ASt-Hil, Fl Bras merid 1: in Mart, Fl bras 12(3): 59 1886, syn nov 154 1825 Waltheria prostrata K Schum, in Mart, Fl Waltheria communis var gracilis (A St-Hil) K bras 12(3): 56 1886, syn nov Schum, in Mart, Fl bras 12(3): 59 1886, syn nov Waltheria americana L form foliis elliptico Waltheria glabriuscula A St-Hil, Fl Bras lanceolatis K Schum & Hassl, in K merid 1: 155 1825 Schum, Bull Herb Boissier ser 2, 4: 72-73 Waltheria communis var glabriuscula (A St-Hil) 1903, syn nov K Schum, in Mart, Fl bras 12(3): 59 1886, syn nov Waltheria communis var hirta K Schum & 145 BONPLANDIA 16(1-2) 2007 Fig 1 Waltheria communis sl A: branch B: base of leaf with 2 stipules C: primary cyme showing 2 bracteoles and 4 bracts around flower pair D: calyx, opened in adaxial view E: thrum flower pistil F: thrum stamens, tube opened, flat G: petal, adaxial view H: seed, apical view (A-H, Cristóbal 2449) Drawn by Liliana Gómez 146 J G Saunders, Sterculiaceae de Paraguay II Fig 2 Waltheria communis sl leaf variation in Amambay (A, C-H) and Caaguazú (B), Paraguay A-H: morphological variation from entirely hirsute or lanate to entirely cinereus-tomentellous; A: sparsely hirsute, surfaces red-brown cf var vulgaris, glabriuscula (Hatschbach & Kummrow 48524, CTES) B: densely hirsute, surfaces red- brown var vulgaris, (Schinini 5761, CTES) C: lanate,