Sampera, a New Genus of Liabeae (Compositae Or Asteraceae) from the Northern Andes

Sampera, a New Genus of Liabeae (Compositae Or Asteraceae) from the Northern Andes

PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 122(2): 155-161. 2009. Sampera, a new genus of Liabeae (Compositae or Asteraceae) from the northern Andes Vicki A. Funk* and Harold Robinson (VAF) U.S. National Herbarium, Department of Botany, MRC 166, National Museum of Natural History, P.O. Box 37012, Smithsonian Institution, Washington, DC. 20013-7012, U.S.A., e-mail: [email protected]; (HR) Department of Botany, MRC 166, National Museum of Natural History, P.O. Box 37012, Smithsonian Institution, Washington, DC. 20013-7012, U.S.A., e-mail: [email protected] Abstract.—The genus Oligactis (Kunth) Cass. is divided into two genera based on the two former subgenera and a new name was necessary for the non-typical subgenus. DNA sequence data have shown that these two groups are not sister taxa and that each is easily defined by morphological characters that include differences in the habit, position of the inflorescence, and the pubescence of the style branches. Sampera, with eight species, is named in honor of Dr. Cristian Samper, Director of the Natural History Museum, Smithsonian Institution. The tribe Liabeae includes a distinctive ment of the tribe in the subfamily but strictly tropical group of American Cichorioideae sensu lato near the Verno- Compositae not recognized at the tribal nieae and the Lactuceae, and this was level until Rydberg (1927) established a later confirmed by a morphological cla- separate tribe in his study of the Mexican distic study by Robinson & Funk (1987). and Central American species. In earlier The structural studies of Robinson studies of the family, the group was (1983a, 1983b) also seemed to have buried in either the Vernonieae (Cassini resolved the generic limits within the 1830) or the Senecioneae (Bentham 1873, group, recognizing 15 genera distributed Hoffmann 1894). The latter treatments from Mexico and Cuba in the north to were particularly unhelpful, with almost Argentina in the south. That apparent all the species placed in one genus, resolution was a major improvement over Liabum Adans., in the Senecioneae but previous classifications, but it was not the with related elements scattered in other final word. tribes: Philoglossa DC. in the He- New collections from northern Peru liantheae, Cacosmia Kunth in the Hele- revealed a previously undescribed genus, nieae, and Chionopappus Benth. in the Bishopanthus H. Rob. (Robinson 1983b). Mutisieae. The chaotic treatment was A morphological cladistic study of the partly because the tribe Liabeae possessed tribe (Funk et al. 1996) provided a a confusing combination of characteris- phylogeny that was similar to the intuitive tics, with styles like the Vernonieae, one described by Robinson (1983a, yellow rays like the Senecioneae, and 1983b) but with a few new sister groups often latex like the Lactuceae. proposed. Re-examination of some other The structural studies of Robinson specimens resulted in the reduction of (1983a) had essentially resolved the place- Austroliabum H. Rob. & Brettell to synonymy under Microliabum Cabrera ! Corresponding author. (Robinson 1990). The application of 156 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON DNA sequencing showed that a new Sampera substituted for the subgeneric genus, Dillandia V. A. Funk & H. Rob. names Oligactis and Andromachiopsis. (Funk & Robinson 2001), was needed for three species, in a group placed previously Inflorescence axillary or terminal, with a in Munnozia Ruiz & Pav. Now, new subglomerate, spiciform, or racemose molecular data from nuclear and chloro- arrangement of heads, heads usually plast DNA sequencing has not only with 6-10 florets; anther appendages supported the establishment of Dillandia, with papillose surfaces Oligactis Inflorescence terminal, with a corymbose but also demonstrated the need for arrangement of heads; heads with another new genus in the Liabeae (Dillon 18-50 florets; anther appendages et al. 2009, Funk & Chan pers. comm.). smooth Sampera Within the Liabeae, the two genera, Liabum and Oligactis (Kunth) Cass., are The characteristics cited remain the clearly closely related (Robinson 1983a). most valid structural distinctions avail- These two genera can be distinguished able for the two genera. In addition, in from other members of the tribe by their habit, typical Oligactis is a more com- pale anther thecae with teeth at the base, plete vine with slender stems, whereas the absence of stomata on the disk corolla Sampera is shrubbier in appearance, with lobes, the lack of latex, and the presence of thicker stems. The style branches of the subquadrate raphids in the achene walls. disk florets are longer than the hispidu- Of the two genera, Liabum has leaves that lous upper part of the style shaft in are trinervate or triplinervate with ascend- Sampera, rather than shorter as in Oli- ing lower secondary veins, whereas Oli- gactis. gactis has leaves with pinnate venation The new genus is named for Cristian (the apomorphic character). However, it is Samper, Director of the National Muse- Oligactis that has been shown to be non- um of Natural History (U.S.A.), former monophyletic. Robinson & Brettell (1974) Director of the Institute Alexander von recognized two subgenera in Oligactis. Humboldt, Santafe de Bogota, Colombia, Because molecular data indicate that these former Acting Secretary of the Smithso- two subgenera are not sister taxa, the nian Institution, 2007-2008, and Honor- atypical subgenus must be elevated to the ary Curator of Tropical Ecology in the genus level. Oligactis subg. Andromachiop- Department of Botany, National Muse- sis H. Rob. & Brettell is therefore removed um of Natural History. Dr. Samper has from Oligactis and placed in the new made a lifelong commitment to the genus Sampera. understanding of life on earth and its conservation, and it is fitting that a genus Systematic Account with some of its taxa in Colombia is named after him. It is interesting to note The DNA sequence data (ITS, ?r«L-F, that one of the eight species in this new ndh¥) separated the two groups in Oli- genus carries the name Sampera cuatre- gactis that were already known to have at casasii (M. O. Dillon & Sagast.) V. A. least subgeneric differences. What was Funk & H. Rob., combining the names of not evident from the morphology was Dr. Samper and the famous Smithsonian that one of the two subgenera was the botanist Dr. Jose Cuatrecasas, who sister taxon of Liabum but the other was worked for many years in Colombia. not (Funk & Chan pers. comm.). Robin- son (1983a) furnished a key to the Sampera V. A. Funk & H. Rob., subgenera that is given here in revised gen. nov. form with the genera Oligactis and Type: Liabum coriaceum Hieron. VOLUME 122, NUMBER 2 157 Oligactis subgen. Andromachiopsis H. of achene wall with subquadrate raphids; Rob. & Brettell, Phytologia 28(1):58 carpopodium short, annuliform, with (1974). Type: Liabum pichinchense small subquadrate cells in 3-5 series, Hieron. walls of cells moderately thickened; pap- Plantae frutescentes subscandentes non pus with 20-35 rather persistent inner laticiferae; folia opposita; inflorescentiae capillary setae sometimes with broadened corymbiformes; thecae antherarum palli- tips, with teeth of setae appearing mucro- dae; appendices apicales antherarum nate-tipped in Hoyer's solution, with laeves; raphidis acheniarum subquadratis. outer series of 7-20 short setae or Scrambling shrubs, moderately branch- squamellae. Pollen spherical, 30-37 um ing, stems terete to strongly hexagonal, in diameter, with spines rather unevenly mostly tomentose, without latex; nodes dispersed, with distinct group of inner with or without disks; leaves opposite; columellae under each spine. petioles with or without wings, sometimes The genus Sampera, with eight species, included in perfoliate leaf pairs; blades is distributed from Colombia southward sharply delimited and rounded to slightly to northern Peru, with the majority of the cordate at base or confluent with petiole, species in Ecuador. The genus Oligactis, ovate to oblong-ovate, margins subentire as now delimited, has species found in to serrate, never angulate, upper surface Costa Rica, Panama, Colombia, and flat to slightly bullate, densely tomentose Venezuela. below, pinnately veined. Inflorescence terminal on branches, corymbiform, pe- Key to the species of Sampera duncles less than 5 cm long, thinly to la. Median involucral bracts ovate, densely tomentose. Heads with involucres shortly acute; longer pappus bristles broadly campanulate, involucral bracts thickened, especially at tips; upper 30-55 in 4-5 series, narrowly ovate to surfaces of leaf blades smooth or lanceolate, tips obtuse to narrowly acute, with exsulcate venation 2 outer surface puberulous to arachnoid lb.All involucral bracts lanceolate, nar- tomentose or hirsute. Ray florets 6-18, rowly acute; longer pappus bristles female; corollas yellow, with elliptical slender with tips only slightly broad- limbs; style branches not spiraled. Disk ened; upper surfaces of leaf blades florets 10-34, bisexual; corollas yellow, often rugose or bullate 4 2a. Nodes with stipuliform disks to 3 or narrowly funnelform, lobes 5, linear 4 times as wide as the stem; heads lanceolate, slightly longer than throat, usually with 12 ray florets and 12 without evident stomata; anther filaments disk florets S. ochracea smooth, with weak annular thickenings in 2b. Nodes without stipuliform disks or walls; thecae pale, digitate at base; with disks not more than twice as endothecial cells oblong, with oval or wide as the stem; heads with 2-10 strap-shaped sclerified bands, with single ray florets and ca. 10-15 disc florets thickening on each transverse wall; apical 3 appendages oblong-ovate, smooth with 3a. Heads with 2-4 ray florets and ca. 15 short-oblong to subquadrate cells. Nec- disk florets; lower surfaces of leaves with thin tomentum allowing dark tary short, not or scarcely lobed. Style color of secondary veins to show. base scarcely broadened; style branches S. cuatrecasasii up to 20 times as long as wide, ca. 1.5 3b. Heads with 8-10 ray florets and ca. times as long as hispidulous part of upper 10 disk florets; lower surfaces of style shaft, tips narrowly obtuse.

View Full Text

Details

  • File Type
    pdf
  • Upload Time
    -
  • Content Languages
    English
  • Upload User
    Anonymous/Not logged-in
  • File Pages
    7 Page
  • File Size
    -

Download

Channel Download Status
Express Download Enable

Copyright

We respect the copyrights and intellectual property rights of all users. All uploaded documents are either original works of the uploader or authorized works of the rightful owners.

  • Not to be reproduced or distributed without explicit permission.
  • Not used for commercial purposes outside of approved use cases.
  • Not used to infringe on the rights of the original creators.
  • If you believe any content infringes your copyright, please contact us immediately.

Support

For help with questions, suggestions, or problems, please contact us