Desert Plants, Volume 25, Number 2 (December 2009)
ABOUT THE COLLECTION
Desert Plants is a unique botanical journal published by The University of Arizona for Boyce Thompson Southwestern Arboretum. This journal is devoted to encouraging the appreciation of indigenous and adapted arid land plants. Desert Plants publishes a variety of manuscripts intended for amateur and professional desert plant enthusiasts. A few of the diverse topics covered include desert horticulture, landscape architecture, desert ecology, and history. First published in 1979, Desert Plants is currently published biannually with issues in June and December.
Digital access to this material is made possible by the College of Agriculture and Life Sciences, Boyce Thompson Southwestern Arboretum, and the University Libraries at the University of Arizona.
Contact Desert Plants at DesertPlants@cals.arizona.edu.
- How the Use of Mesquite Impacts Grass Availability, Wild Ass Sanctuary, India
- The Double-Cut Techniques for Grafting Cacti to Trichocereus pachanoi Rootstock
- Note from the Director
- Dedication of Boyce Thompson Arboretum April 1929
- World Vegetation in Relation to the Boyce Thompson Southwest Arboretum
- Effect of Pre-germination Treatments on Seed Germination of Helianthemum lippii (L.) Dum.Cours.
- Lonesome Valley: Rio Huasco, River of the Atacama
Effect of Pre-germination Treatments on Seed Germination of Helianthemum lippii (L.) Dum.Cours.Helianthemum lippii (L.) Dum. Cours. is a perennial shrubby plant 10-45 cm tall that belongs to the family Cistaceae. The effects of pretreatments on germination of Helianthemum lippii provide information regarding germination requirements of this species, which could be used for conservation studies. Five different pretreatment were applied to enhance seed germination. Scarification followed by germination at 6 different constant temperatures (10, 15, 20, 25, 30 and 35°C) with continuous light or dark, Scarification followed by GA3 soaking (100, 250,500,750 and 1000 ppm), Heat and moist stratification (only intact seeds), KNO₃ and H₃BO₃ soaking (only intact seeds). The results obtained from this study indicate that germination in H. lippii was promoted by scarification. Scarification of seeds resulted in high germination while increasing germination temperature (35°C) decreased the germination of scarified seeds. Exposure to light and dark had no effect on germination. Heat stratification, cold stratification, KNO₃ and H₃BO₃ treatments were ineffective in increasing germination of H.lippii seeds. Scarification yielded maximum germination without soaking in GA₃ It increased the germination of Helianthemum lippii seeds from 1 to 99%. Increase in GA₃ concentration decreased the germination of this species. Scarification succeeded in breaking dormancy of H.lippii seeds suggesting that this species exhibits seed coat dormancy and in nature it may happen due to the abrasion of seed coat by sand particles or other biotic and abiotic factors.
How the Use of Mesquite Impacts Grass Availability, Wild Ass Sanctuary, IndiaWe examined the impact of an exotic mesquite (Prosopis juliflora) on grass availability in the Wild Ass Sanctuary (WAS), Western India, which is the only habitat for the endangered Indian wild ass (Equus hemionus khur). These data are necessary for the management of endangered species in desert ecosystems where resources fluctuate widely. We collected information on the size of mesquite branches used by people for fuelwood and the impact of branches that were left on the ground on grass cover and biomass during 1989-1990. People preferred fuelwood branches of mesquite 5-15cm in diameter; the remaining thorny branches are left in the field, which reduces the availability of grass for foraging. Most grasses that grow under the discarded mesquite branches are protected whereas grasses without this protection are grazed. We correlated the percent grass cover with the number of twigs left on the ground (r = 0.74). Grasses protected due to the thorny branches leftover after mesquite collection, provide sources of seeds but reduce overall availability of forage leading to increased crop depredation by wild ass. Managing mesquite branches in WAS is important to provide more grazing areas for minimizing crop predation by wild