Overview

Brief Summary

Taxon Biology

The tribe Liabeae is a distinctive but strictly tropical group of Compositae (Asteraceae) from the Americas. Recent studies require the recognition of a new genus (see below).

The new genus is named for Cristián Samper, Director of the National Museum of Natural History (USA); former Director of the Instituto Alexander von Humboldt, Santafé de Bogotá, Colombia; former Acting Secretary of the Smithsonian Institution, 2007-2008; and Honorary Curator of Tropical Ecology in the Department of Botany, National Museum of Natural History. Dr. Samper has made a lifelong commitment to the understanding of life on earth and its conservation and it is fitting that a genus with some its taxa in Colombia is named after him. It is interesting to note that one of the eight species in this new genus carries the name Sampera cuatrecasasii (M.O. Dillon & Sagást.) V. A. Funk & H. Rob., combining the names of Dr. Samper and the famous Smithsonian Botanist Dr. José Cuatrecasas who worked for many years in Colombia.

The genus contains eight species:

Sampera asplundii (H. Rob.) V.A. Funk & H. Rob., comb. nov. Oligactis asplundii H. Rob., Phytologia 35(3): 200 (1977).

Ecuador.

Sampera coriacea (Hieron.) V.A. Funk & H. Rob., comb. nov. (Figs.1. 2).

Liabum coriaceum Hieron., Bot. Jahrb. Syst. 29: 58 (1900). Oligactis coriacea (Hieron.) H. Rob. & Brettell, Phytologia 28(1): 58 (1974).

Liabum scandens Domke in Diels, Bibloth. Bot. 116: 167 (1937). Oligactis scandens (Domke) H. Rob. & Brettell, Phytologia 28(1): 59 (1974).

Liabum granatense Cuatrec., Feddes Repert. Spec. Nov. Regni Veg. 55: 128 (1953). Oligactis granatensis (Cuatrec.) H. Rob. & Brettell, Phytologia 28(1): 58 (1974).

Oligactis coriacea var. granatensis (Cuatrec.) H. Rob., Phytologia 35(3): 201 (1977).

Colombia, Ecuador, Peru.

Sampera cuatrecasasii (M.O. Dillon & Sagást.) V.A. Funk & H. Rob., comb. nov.

Oligactis cuatrecasasii M.O. Dillon & Sagást., Arnaldoa 2(2): 25 (1994)[1995].

Peru.

Sampera cusalaguensis (Hieron.) V.A. Funk & H. Rob., comb. nov.

Liabum cusalaguense Hieron., Bot. Jahrb. Syst. 29: 55 (1900). Oligactis cusalaguensis (Hieron.) H. Rob. & Brettell, Phytologia 28(1): 58(1974).

Ecuador.

Sampera ecuadoriensis (Hieron.) V.A. Funk & H. Rob., comb. nov.

Liabum ecuadoriense Hieron., Bot. Jahrb. Syst. 19: 60 (1894). Oligactis ecuadoriensis (Hieron.) H. Rob. & Brettell, Phytologia 28(1): 58 (1974).

Ecuador.

Sampera ochracea (Cuatrec.) V.A. Funk & H. Rob., comb. nov. Liabum ochraceum Cuatrec., Collect. Bot. Barcilone 3: 302 (1953). Oligactis ochracea (Cuatrec.) H. Rob. & Brettell, Phytologia 28(1): 58 (1974).

Peru.

Sampera pastoensis (Cuatrec.) V.A. Funk & H. Rob., comb. nov. Liabum pastoense Cuatrec., Not. Fl. Colomb. 6: 36 (1944). Oligactis pastoensis (Cuatrec.) H. Rob. & Brettell, Phytologia 28(l): 58 (1974).

Colombia.

Sampera pichinchensis (Hieron.) V.A. Funk & H. Rob., comb. nov. Liabum pichinchense Hieron., Bot. Jahrb. Syst. 29: 56 (1900). Oligactis pichinchensis (Hieron.) H. Rob. & Brettell, Phytologia 28(1): 59 (1974).

Liabum hallii Hieron., Bot. Jahrb. Syst. 29: 57 (1900). Oligactis hallii (Hieron.) H. Rob. & Brettell, Phytologia 28(1): 58 (1974).

Ecuador.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Funk, Vicki

Source: Compositae

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Comprehensive Description

General Description

Sampera V.A.Funk & H. Rob., gen. nov. Type: Liabum coriaceum Hieron.

Oligactis subgen. Andromachiopsis H. Rob. & Brettell, Phytologia 28(1): 58 (1974). Type: Liabum pichinchense Hieron.

Plantae frutescentes subscandentes non laticiferae; folia opposita; inflorescentiae corymbiformes; thecae antherarum pallidae; appendices apicales antherarum laeves; raphidis acheniarum subquadratis.

Scrambling shrubs, moderately branching, stems terete to strongly hexagonal, mostly tomentose, without latex; nodes with or without disks; leaves opposite; petioles with or without wings, sometimes included in perfoliate leaf pairs; blades sharply delimited and rounded to slightly cordate at base or confluent with petiole, ovate to oblong-ovate, margins subentire to serrate, never angulate, upper surface flat to slightly bullate, densely tomentose below, pinnately veined. Inflorescence terminal on branches, corymbiform, peduncles less than 5 cm long, thinly to densely tomentose. Heads with involucres broadly campanulate, involucral bracts 30-55 in 4-5 series, narrowly ovate to lanceolate. tips obtuse to narrowly acute, outer surface puberulous to arachnoid tomentose or hirsute. Ray florets 6-18, female; corollas yellow, with elliptical limbs; style branches not spiraled. Disk florets 10-34, bisexual; corollas yellow, narrowly funnelform, lobes 5, linear lanceolate, slightly longer than throat, without evident stomata; anther filaments smooth, with weak annular thickenings in walls; thecae pale, digitate at base; endothecial cells oblong, with oval or strap-shaped sclerified bands, with single thickening on each transverse wall; apical appendages oblong-ovate, smooth with short-oblong to subquadrate cells. Nectary short, not or scarcely lobed. Style base scarcely broadened; style branches up to 20 times as long as wide, ca. 1.5 times as long as hispidulous part of upper style shaft, tips narrowly obtuse. Achenes prismatic, with 5-8 ribs, bearing contorted setulae and small glandular dots, cells of achene wall with subquadrate raphids; carpopodium short, annuliform, with small subquadrate cells in 3-5 series, walls of cells moderately thickened; pappus with 20-35 rather persistent inner capillary setae sometimes with broadened tips, with teeth of setae appearing mucronate-tipped in Hoyer's solution, with outer series of 7-20 short setae or squamellae. Pollen spherical, 30-37 µm in diam., with spines rather unevenly dispersed, with distinct group of inner columellae under each spine.

The genus Sampera is distributed from Colombia southward to northern Peru with the majority of the species in Ecuador. The genus Oligactis, as now limited, has species found in Costa Rica, Panama, Colombia and Venezuela. The new genus contains eight species.

Key to the species of Sampera

1a. Median involucral bracts ovate, shortly acute; longer pappus bristles thickened, especially at tips; upper surfaces of leaf blades smooth or with exsulcate venation . . . . . . . . . . 2

2a. Nodes with stipuliform disks to 3 or 4 times as wide as the stem; heads usually with 12 ray florets and 12 disk florets. . . . . S. ochracea

2b. Nodes without stipuliform disks or with disks not more than twice as wide as the stem; heads with 2-10 ray florets and ca. 10-15 disc florets. . . . . . . . . . . . . 3

3a. Heads with 2-4 ray florets and ca. 15 disk florets; lower surfaces of leaves with thin tomentum allowing dark color of secondary veins to show. . . . . . . . . S. cuatrecasasii

3b. Heads with 8-10 ray florets and ca. 10 disk florets; lower surfaces of leaves with thick tomentum obscuring color of secondary veins . . . . . . . . . . . S. coriacea

1b. All involucral bracts lanceolate, narrowly acute; longer pappus bristles slender with tips only slightly broadened; upper surfaces of leaf blades often rugose or bullate. . . . . . 4

4a. Leaf blades ovate-lanceolate; peduncles with appressed arachnoid tomentum; plants from near or below 2500 m . . . . S. asplundii

4b. Leaf blades mostly oblong-ovate; peduncles with floccose tomentum; plants mostly above 2500m . . . . . . .5

5a. Base of leaf blade abruptly acute to subtruncate. . . . . . . . . . 6

6a. Heads with (5-)6-8 ray florets; inner pappus bristles 3.5-4.0 mm long . . . . . S. ecuadoriensis

6b. Heads with 14-18 ray florets; inner pappus bristles 4.5-5.5 mm long. . . . . . . S. pichinchensis

5b. Base of leaf blade acuminate to decurrent.. . . . . . . . . . . . . . . . .7

7a. Petiole winged, continuous between decurrent base of leaf blade and nodal disk . . . . . . . . . . S. cusalaguensis

7b. Petiole not winged . . . . . . . . . . .S. pastoensis

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Funk, Vicki

Source: Compositae

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Evolution and Systematics

Evolution

Systematics

The Liabeae were not recognized at the tribal level until Rydberg (1927) established a separate tribe in his study of the Mexican and Central American species. In earlier studies of the family, the group was buried in either the Vernonieae (Cassini 1830) or the Senecioneae (Bentham 1873; Hoffmann 1894). The latter treatments were particularly unhelpful, with almost all the species placed in one genus, LiabumAdans., in the Senecioneae, but with related elements scattered in other tribes: Philoglossa DC. in the Heliantheae, Cacosmia Kunth in the Helenieae, and Chionopappus Benth. in the Mutisieae. The chaotic treatment was partly because the tribe Liabeae possessed a confusing combination of characteristics, with styles like the Vernonieae, yellow rays like the Senecioneae, and often latex like the Lactuceae.

The structural studies of Robinson (1983a) had essentially resolved the placement of the tribe in the subfamily Cichorioideae s. l. near the Vernonieae and the Lactuceae but this was confirmed by a morphological cladistic study in 1987 (Robinson & Funk). The structural studies of Robinson (1983a, b) also seemed to have resolved the generic limits within the group, recognizing 15 genera distributed from Mexico and Cuba in the north to Argentina in the south. That apparent resolution was a major improvement over previous classifications, but it was not the final word.

New collections from northern Peru revealed a previously undescribed genus Bishopanthus H. Rob. (Robinson 1983b). A morphological cladistic study of the tribe (Funk & al. 1996) provided a phylogeny that was similar to the intuitive one provide by Robinson (1983a, b) but with a few new sister groups proposed. Reexamination of some other specimens resulted in the reduction of AustroliabumH. Rob. & Brettell to synonymy under Microliabum Cabrera (Robinson 1990). The application of DNA sequencing showed that a new genus, Dillandia V.A. Funk & H. Rob. (Funk & Robinson 2001), was needed for three species, in a group placed previously in Munnozia Ruiz & Pav. Now, new molecular data from nuclear and chloroplast DNA sequencing has not only supported the establishment of Dillandia, but also demonstrated the need for another new genus in the Liabeae (Funk & Chan, in prep.).

Inflorescence axillary or terminal, with a subglomerate, spiciform, or racemose arrangement of heads, heads usually with 6-10 florets; anther appendages with papillose surfaces. . . . . . . . . Oligactis

Inflorescence terminal, with a corymbose arrangement of heads; heads with 18-50 florets; anther appendages smooth . . . . Sampera

The characteristics cited remain the most valid structural distinctions available for the two genera. In addition, in habit, typical Oligactis is a more complete vine with slender stems while Sampera is more shrubby in appearance with thicker stems. The style branches of the disk florets are longer than the hispidulous upper part of the style shaft in Sampera, rather than shorter as in Oligactis.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Funk, Vicki

Source: Compositae

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!