Species Of Apocynaceae Research Articles

Secamone brevicoronataandS. pedicellaris (Apocynaceae), two new species from Madagascar

Klackenberg, J.: Secamone brevicoronata and S. pedicellaris (Apocynaceae), two new species from Madagascar. — Willdenowia 30: 45–51. 2000. — ISSN 0511-9618.Secamone brevicoronata and S. pedicellaris, two species of Apocynaceae s.l., Secamoneae, from Madagascar, are described as new to science, illustrated and compared with related taxa.

Two New Species of Secamone (Apocynaceae, Secamoneae) from Madagascar

Secamone schatzii and S. linearis are two new species of Apocynaceae, Secamoneae, from the Malagasy eastern lowland forest and from the Marojejy mountains in northeastern Madagas- car, respectively. Both species are related to Seca- mone tenuifolia and S. glaberrima from the Central Plateau. The new species are described, illustrated, and compared with related taxa. A key to the eight species in the Secamone tenuifolia group is given. Secamone R. Brown is a paleotropical genus of suffrutescent twiners or small scrambling herbs, rarely erect shrubs, with usually small white to yel- low flowers. In a revision of Secamone in the Mad- agascar Region (Klackenberg, 1992), 56 species were recognized from Madagascar. Since then two additional species have been described from this island (Klackenberg, 1997, 1998). In the course of preparing the tribe Secamoneae for the Flore de Madagascar et des Comores, while examining re- cent material from the MO herbarium, I encoun- tered two specimens from eastern Madagascar that do not fit in any of the hitherto known 58 species. The specimens were collected in the lowland at Nosy Mangabe and in the mountains in Marojejy, respectively. After morphological analysis it is ev- ident that they represent two new species of Seca- mone. Both are herein described, illustrated, and given the names Secamone schatzii and S. linearis.

A New Marsdenia (Apocynaceae, Asclepiadoideae) from Baja California

Marsdenia carterae, a new species of Apocynaceae (Asclepiadoideae, Marsdenieae) from Baja California Sur, Mexico, is described and illustrated. This is the first North American species of Marsdenia with verticillate leaves and is also notable in lacking a developed corona and for its non-twining habit. Marsdenia carterae W. D. Stevens & Ju6rez-Jaimes, sp. nov. TYPE: Mexico. Baja California Sur: eastern escarpment of Cerro Mechudo between Portezuelo de San Antonio and La Sabanilla, Sierra de la Giganta, 675 m, 24?49'N, 110?44'W, occasional on cliffs and talus, 4 Nov. 1971, R. Moran 18990 (holotype, UC; isotype, MO). Figure 1. Distribution map and additional images can be found in W3TROPICOS (http://mobot.mobot.org/ Pick/Search/pick.html). A speciebus ceteris Marsdeniae regionis foliis verticillatis habitu haud volubili corona obsoleta distinguenda. Shrub to 1.5 m tall and 2.5 m wide, branches decumbent or pendent, stems with thick, dark, corky bark on older wood, bark thinner and whitish on younger wood, branchlets roughened by raised leaf scars, densely pubescent with appressed, ? curly, multicellular hairs to ca. 0.15 mm long, internodes 1-5(-25) mm long, ribbed except when still herbaceous; latex white; roots unknown. Leaves 3, rarely 1 or 2, per node, without pseudostipules but with 1-3 colleters in each stipular area, blades 5-8.5 cm long, 4-8 mm wide, very narrowly lanceolate to lorate or linear, apex acute to rounded or minutely mucronate, base acute, minutely pubescent when young, glabrescent except hairs + persistent along midrib of both sides, midrib prominent below, sulcate above, especially near petiole, venation pinnate, lateral veins obscure, ca. 7-13 pairs, middle veins arising ca. 550 to midrib, margin thickened and + revolute, colleters 0-3, at adaxial base of blade; petiole 4-6 mm long, with indumentum of stem. Inflorescence extra-axillary, 1 per node and mostly not on adjacent nodes, cymose, congested-racemiform, or congested-paniculiform, sometimes bearing a fully formed leaf opposite the first flower or branch, 5-15-flowered, with indumentum of stem, peduncle 2-5 mm long, pedicel 3-4 mm long, bracts to 2.5 mm long, 1.1 mm wide, lanceolate; calyx divided to base, with 1-2 colleters below each sinus within, lobes 2.22.5 mm long, 0.9-1.4 mm wide, ovate or elliptic, with rounded tips, green with scarious margins, pubescent outside, glabrous inside; corolla rotate with ascending lobes, aestivation narrowly imbricate and dextrorse, glabrous outside, glabrous inside except throat densely barbate with stiff, white, unicellular hairs to ca. 0.5 mm long, these spreading at sinuses and retrorse between, cream-white, tube 1.2-1.4 mm long, lobes 2.3-3.1 mm long, 1.5-2.2 mm wide, elliptic with obliquely rounded tips; gynostegium ca. 2.2 mm tall, stipe ca. 1.7 mm long, corona obsolete, anthers rectangular, ca. 1.0 mm long, 1.5 mm wide, terminal appendages ovate, ca. 0.8 mm long, 0.6 mm wide, + erect and appressed to style apex, wings straight, parallel, ca. 0.5 mm long, 0.3 mm wide; corpusculum ca. 0.25 mm long, 0.08 mm wide, linear, dark red-brown, translator ca. 0.08 mm long, translucent and unwinged, pollinia erect, ca. 0.25 mm long, 0.15 mm wide, obovate, pale yellow; style apex conical, smooth, shallowly 2-lobed at apex, ca. 0.4 mm wide. Follicles single or occasionally paired, divergent when paired, fusiform-attenuate to napiform, somewhat asymmetrical, smooth, 7-12 cm long, 1.3-1.8 cm wide, densely tomentose, follicle wall ca. 0.5 mm thick, herbaceous; seeds obovate, flat, ca. 11 mm long, 7 mm wide, pale yellow-brown with a pale brown margin 0.4-0.5 mm wide, margin smooth and entire, surface smooth and glossy, coma about 2.5 cm long, pale tawny. NOVON 9: 565-567. 1999. This content downloaded from 207.46.13.60 on Thu, 21 Apr 2016 07:10:49 UTC All use subject to http://about.jstor.org/terms

Agrobacterium-mediated transformation of the terpenoid indole alkaloid-producing plant species Tabernaemontana pandacaqui.

Plants of the Apocynaceae family produce a wide range of terpenoid indole alkaloids (TIAs) which have important pharmaceutical applications. Studies of the molecular mechanisms controlling TIA biosynthesis may eventually provide possibilities to improve product yield by genetic modification of plants or cell cultures. However, these studies suffer from the lack of transformation/regeneration protocols for Apocynaceae plants. We chose to study the feasibility of Agrobacterium tumefaciens-mediated transformation of Tabernaemontana pandacaqui, because of the availability of an efficient regeneration procedure for this member of the Apocynaceae family. A procedure to produce transgenic T. pandacaqui plants was established, albeit with low efficiency. Transgenic expression was demonstrated of an intron-containing β-glucuronidase reporter gene and of a gene coding for the TIA biosynthetic enzyme strictosidine synthase from Catharanthus roseus, another Apocynaceae species.

Anatomical Structures of the VA Mycorrhiza in the Apocynaceae (Gentianales)

AbstractRoots of 19 Apocynaceae species were studied anatomically with respect to their symbiosis with VAM‐fungi. In plants collected from the field, VAM‐fungi were established in the root cortex. Also, inoculations with different Glomus species on the cultured plants are very successful in the infection and colonization of the root cortex.After penetration of the rhizodermis, the special exodermal short cells become colonized by winding hyphae. Then, in the root cortex of many Apocynaceae species, the VAM‐fungi produce intercellular running hyphae which leads to extensive colonization of the root. Arbuscules develop on intracellular running hyphae, whereas vesicles develop mainly on intercellular hyphae. Except for some special details, this is the most common type of colonization of VAM fungi in flowering plants.But in Amsonia tabernaemontana, Nerium oleander, and Thevetia peruviana, another type of colonization could be observed. In these species, the colonization of the hyphae within the root cortex is only possible by intracellular growth. Intercellular running hyphae in the root are lacking. Therefore, after penetration the colonization in the cortex is cluster‐like and strictly limited. Only by additional penetrations from hyphae in the soil, will roots show heavy infestations. This type of growth of the VAM fungi in the root is well known from the Gentianaceae and was explained as a structural incompatibility.In Catharanthus roseus, Pachypodium lamerei, and Trachelospermum jasminoides, intermediate stages of both types of colonization could be described. The results are discussed in the search for possible stimulants for structural incompatibility.

Palynological Study of the Apocynaceae of Taiwan

Abstract Ten genera and seventeen species of Apocynaceae from Taiwan were studied by means of transmission electron microscopy. Five types of exine stratification are recognized based on ultrastructural features and apparent chemical characteristics. In type I, the nexine corresponds to a foot layer plus the endexine; in type II, the nexine corresponds directly to the foot layer only; in type III, the nexine corresponds directly to the endexine only; in type IV, the nexine is absent and the infratectal stratum is a granular layer and in type V, the nexine is also absent, but the infratectal stratum is a reticular layer at upper and lower portions underlain by a granular layer in the middle with granules of varying size and shape. Except for the species of Trachelospermum, the rest of the infrageneric taxa can be keyed out by palynological characters. Possible evolutionary trends in exine stratification are proposed.

New Species and Combinations in Apocynaceae from Peru and Adjacent Amazonia

Among recent collections from Peru and adjacent regions are the six new species of Apocynaceae described here. A new combination is also proposed for the widespread plant previously known as Mandevilla velutina. The genus Pacouria is reported for the first time from Peru and the very unusual fruits of Allamanda weberbaueri described for the first time.

Screening of antimicrobial activity of some plants belonging to the Apocynaceae and Loganiaceae

A review is given of the literature on the antimicrobial activity of various indole alkaloids. The data are briefly discussed. A screening was performed of a series of plants belonging to the indole alkaloid rich plant families Apocynaceae and Loganiaceae, 25 materials representing 14 Apocynaceae species and 54 materials representing 41 Strychnos species were investigated. No activity against the yeast or the fungus, used as test organisms was found. A number of extracts showed activity against the gram-positive test organisms, 4 species showed activity against gram-negative bacteria.

Corolla tube formation in six species of apocynaceae

Corolla tube formation inTrachelospermum asiaticum, Nerium indicum var.leucanthum, Anodendrom affine, Vinca major, Catharanthus roseus andAmsonia elliptica was investigated anatomically.The corolla tube formation among these species is basically similar. The bases of petal primordia extend laterally to the interprimordial regions, the upward growth occurrig at those regions just beside the petal bases. The extending petal bases connect with each other at the bases of the abaxial side of stamen primordia in the early stage of the corolla development. The upward growth at the coonnected regions results in the formation of a short corolla tube but is weakened rapidly. At the stage of the mutual connection of petal bases, a common base of petal and stamen primordia is initiated. This common base develops into the lower portion of the corolla tube, i.e. the portion below the stamen insertion.In a relatively late stage, adjacent margins, of the corolla lobes fuse postgenitally at their lower portions, resulting in the formation of almost all of the upper portion of the corolla tube.The corona inNerium andVinca is initiated by the active adaxial growth of the upper portion of the corolla tube.

Notes concerning the isolation of quaternary alkaloids from Pleiocarpa tubicina Stapf

AbstractThe following quaternary indole alkaloids have been isolated from the root bark of the Apocynaceae species Pleiocarpa tubicina Stapf: huntrabrine methochloride, kopsinic acid methochloride, N(a)‐methyl‐sarpagine methochloride and macusine B chloride.