Clethra Alnifolia Research Articles

Inoculation of native woody plants with vesicular-arbuscular mycorrhizal fungi for phosphate mine land reclamation

Cuttings of Aronia arbutifolia (L.) Ell., Clethra alnifolia L., Cornus foemina Mill., Ilex glabra (L.) Gray, and Viburnum nudum L. were inoculated in a rooting bed with Glomus etunicatum (Nicol & Gerd.) Gerdemann & Trappe, Glomus intraradices Schenck & Smith, or a mixed culture that consisted of several unidentified Glomus spp. After 7 weeks, a low level of root colonization (overall mean of 2%) was recorded for all plant species except V. nudum. These low percentages were sufficient to obtain well-colonized plants (overall mean of 57%) after rooted cuttings were transplanted to potting medium and grown in a shadehouse for 7 months. Inoculation had no effect on plant growth or survival after outplanting to a site that contained abundant clay aggregates and where controls became colonized by vesicular-arbuscular mycorrhizal (VAM) fungi. Further studies are needed on sites differing in physical and chemical properties before reliable conclusions can be drawn concerning the use of VAM-fungus inoculation in phosphate minelands reclamation.

Japanese Beetle (Coleoptera: Scarabaeidae): Influence of Favored Food Plants on Feeding Response

Foliage and floral samples from 45 favored host plants (24 families) of the Japanese beetle, Popillia japonica Newman, were evaluated to determine their influence on the feeding response of the insect under laboratory conditions. Foliage from two plants, the red raspberry, Rubus idaeus L., and the European grape, Vitis vinifera L., and rose petals, Rosa sp., induced greater feeding than did sassafras, Sassafras albidum (Nutt.) Nees, the foliage of which was used as a comparison standard. Foliage from 25 other plants, silks from corn, Zea mays L., and blossoms of Rose-of-Sharon, Hibiscus syriacus L., induced feeding comparable to that of the sassafras standard. Leaves from several plants reported to be heavily attacked, however, including sweet pepperbush, Clethra alnifolia L., rhubarb, Rheum rhabarbarum L., black cherry, Prunus serotina J. F. Ehrh., apple, Malus × domestica Borkh. ‘Rome’, peach, Prunus persica (L.) Batsch ‘Elberta’, and asparagus, Asparagus officinalis L., were fed upon significantly less than sassafras.

Elemental Composition of Epiphytic Lichens from Okefenokee Swamp

Elemental Composition of Epiphytic Lichens from Okefenokee Swamp

The Use of Water and Minerals by Evergreen and Deciduous Shrubs in Okefenokee Swamp

Shoot water potentials, leaf diffusion resistances, and foliar concentrations of Ca++, Mg++, K+, N, and P were measured in an evergreen shrub (Lyonia lucida [Lam.] K. Koch) and a deciduous shrub (Clethra alnifolia L.) in Okefenokee Swamp, Georgia. An upland, evergreen species (L. ferruginea [Walt.] Nutt.) was included for comparison. Clethra alnifolia generally had the highest mineral contents (percentage of dry weight) and the highest water loss in transpiration. During several 24-h monitoring periods, the lowest observed shoot water potentials (L. lucida, -10.1 bars; C. alnifolia, -12.5 bars; L. ferruginea, -17.2 bars) did not suggest "physiological drought" in the swamp species. Only L. lucida showed any evidence of midday stomatal closure. In this warm-temperate swamp, evergreen species have the potential for greater efficiency of mineral use and productivity, largely due to their leaf longevity. In addition, sclerophyllous tissue is probably useful in defense against herbivores.

The Floral Morphology of Clethra alnifolia with some Notes on C. acuminata and C. arborea. Contributions from the Hull Botanical Laboratory 632

1. Descriptions of the organography, floral development, vascular anatomy of the flower, anatomy of the floral organs, microsporogenesis, and megasporogenesis in Clethra alnifolia and notes on the organography, vascular anatomy, and anatomy of floral organs in C. acuminata and C. arborea are presented. 2. The Clethraceae, in common with most of the Ericales, are pentacyclic (the outer whorl of stamens opposite the petals), pentamerous in most floral whorls, actinomorphic, hypogynous, and hermaphroditic. Characteristics peculiar to the family are a fully developed endothecium in the anther and a three-branched style. Other features found in the Clethraceae and in only a few other species in the Ericales are choripetaly, absence of a disk, "stellate" pubescence, extrorse position of the anthers during development, single pollen grains, and a tricarpellate ovary. 3. In the receptacle the vascular cylinder is considerably compacted in the region where the traces originate. The first whorl, consisting of five bundles, forms the median sepal supply. The lateral traces of adjacent sepals arise as common bundles from the large strands of vascular tissue left between the median sepal gaps. Immediately above these common bundles the traces to the petals and petalad stamens arise together. Traces to the sepalad stamens arise from one side of the median sepal gap as do also the dorsal carpel bundles. The latter form the stylar vascular supply; the septal traces, independent in origin, fade out without reaching the style, and the ventral carpel bundles supply the placentae and ovules. 4. Inversion of the extrorsely developed anther occurs at anthesis. The pattern of microsporogenesis is as in most angiosperms. Pollen grains are single and probably two celled at the time of shedding. 5. In the ovule a single archesporial cell gives rise to the megaspore mother cell which, following meiosis, divides to form a linear tetrad. Usually the chalazal spore functions. The seven-celled, eight-nucleate, megagametophyte develops according to the Normal-(Polygonum-) type. Disintegration of the nucellus and development of an "epithelial"-like layer of the single integument begins prior to gametophyte development. Fusion of the polar nuclei occurs before fertilization. 6. C. acuminata and, to a lesser extent, C. arborea differ from C. alnifolia in the vascular supply of the sepals. Some variation in the type of pubescence occurs in C. acuminata as compared with the two other species. In C. arborea branches of the ventral carpel bundles as well as of the dorsal carpel bundles traverse the style. 7. A comparison of the characteristics of the Clethraceae, as exemplified by the three species studied, with those of other groups in the Ericales shows that the family is not so primitive with respect to the vascular anatomy of the flower as it is with respect to certain of its other morphological features. 8. Drude's separation of the three species studied into two sections appears to be justifiable on the basis of organography. Observed anatomical variations in the three species, however, neither support nor refute his classification.

DESCRIPTION OF TWO LEPIDOPTEROUS LARVÆ

Botis magistralis, Grote.Head pale brown, smooth, shining; mouth parts dark brown; cervical shield brown, divided in the middle by the color of the body, which is translucent greenish-white; along the dorsal region two rows of shining pale brown piliferous spots, four on each segment, those on the first segment darker in color. All the spots bear a short light brown hair. Thoracic feet, abdominal and anal legs concolorous with the body. Length 30 mm. Lives singly on Clethra alnifolia, in a number of leaves fastened together with silken threads. Pupated July 6th. Imagos emerged July 17th and 18th.