| | |
 |
|
| 
| ||
 |
|
|
|
 |
|
Wildlife, Animals, and Plants |
|
|||
|
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
GENERAL BOTANICAL CHARACTERISTICS:Soaptree yucca has woody, succulent stems often 9-12 feet (3-4 m) high (occasionally up to 30 feet (9 m) [24]. Utah yucca is smaller, with stems up to approximately 4.5 feet (1.3 m) [49]. Growth form of soaptree yucca varies from a single, erect, trunklike stem to several stems in clumps of 1.6 to 8.2 feet (0.5-2.5 m) in diameter [48]. Like all yucca species with dehiscent fruits, soaptree yucca is rhizomatous. The species is unique in that the rhizome develops downward and later begins lateral root extensions. The "vertical rhizome" as described by Webber [48] commonly grows to 3-5 feet (1-1.5 m) deep, and 3-6 inches (8-15 cm) in diameter. Lateral roots are 6-10 inches (15-20 cm) long and 1-3 inches (2.5-8 cm) in diameter [48]. Leaves are slender, sharply pointed, 2-3 feet (0.6-1 m) in length, and grow in variably loose to densely crowded clumps [8]. Stems are often clumped because they are derived from common rhizome systems [48]. Leaves grow in a tuft at the top of the stem [24]. The stem can be either upright or procumbent [25]. The inflorescence is an open, branching panicle [8], producing a capsular, fleshy, and dehiscent fruit. The fruit commonly contains about 150 viable ovoid seeds [2].
RAUNKIAER [37] LIFE FORM:Stem succulent
REGENERATION PROCESSES:Soaptree yucca produces from seed and by sprouting. Soaptree yucca has an obligate mutualistic relation to its pollinator the yucca moth (Tegeticula yuccsella) [21]. The yucca moth pollinates its flowers and moth larvae feed on the developing fruit, decreasing viable seed production by up to 20% [1,25]. Soaptree yucca aborts many fruits, killing larvae therein; this process is thought to help maintain the mutualistic relationship [22]. Fruits produce many small, windblown seeds [1,25]. Little information is published regarding seed longevity and seed banking. In most cases, reproduction is primarily clonal [8,8,35,42,43]. Sprouts originate from meristems on rhizomes and the root crown. Soaptree yucca may also resume growth from unburned portions of the stem [40,43,48,48]. Seedling establishment is not thought to be a reliable means of regeneration for soaptree yucca, primarily because germination and seedling establishment are controlled by a number of factors including, most importantly, adequate soil moisture and facilitation by other shrubs [42,43].
SITE CHARACTERISTICS:Soaptree yucca grows on a wide range of sites but prefers coarse soils [8,9,17]. In the Guadalupe Mountains of New Mexico, soaptree yucca is most prevalent on gypsum dunes, but also present on sandhills derived from quartz [9]. In the Davis Mountains of Texas and Coahuila, Mexico, soaptree yucca is common on gentle to moderate slopes with coarse soils derived from igneous materials [17]. In the Chisos Mountains of the Rio Grande area of Texas, soaptree yucca "reached best development" on eroded rocky slopes [30]. The climate of the Jornada Experimental Range is typical of the semidesert grassland communities where soaptree yucca is prevalent. At this site there is an average of 8.33 inches (215 mm) precipitation per year, with 64% occurring in May through September. Mean annual temperature is 59 degrees Fahrenheit (15 oC) [6]. In southwestern Texas and central and southern Arizona soaptree yucca grows between 1,500 and 6,000 feet (450- 1,220 m) in elevation, Verdi yucca grows in central Arizona between 3,000 and 6,000 feet (910-1,220 m) in elevation [24].
SUCCESSIONAL STATUS:Soaptree yucca occurs in both early and later succession. Early descriptions of honey mesquite (Prosopis glandulosa) dunes list soaptree yucca as a secondary colonizer [7]. Honey mesquite was dominant on unprotected areas with frequent wind erosion or sand aggradation, while soaptree yucca established after several years of favorable conditions on sites where topography or honey mesquite had stabilized soils [7]. A more recent source cites soaptree yucca as a major component of dune vegetation in the Mesilla Basin of New Mexico. The author reported that mounds of sand formed around soaptree yucca, implying that it did not require other shrubs to stabilize sand and advance succession [29].
SEASONAL DEVELOPMENT:In Arizona, New Mexico, and Texas soaptree yucca flowers between May 15 and July 15; fruit ripens between August 1 and October 1; and seed is dispersed in September and October [2]. On the Jornada Experimental Range soaptree yucca initiated new leaf growth in May and June and continued producing new leaves throughout the summer [8]. Leaf elongation occurred until early fall. The period of most rapid growth was at the end of July, when average length of new leaves doubled in 1 week [8]. During their 1st year leaves grow parallel to the stem. In subsequent years they are oriented outward, providing some protection for the apical meristem [8]. Leaves remain green for 3-5 years. Dry leaves remain on the stem [8].
Related categories for SPECIES: Yucca elata | Soaptree Yucca |
 |
 | |
| |
| |
| Content on this web site is provided for informational purposes only. We accept no responsibility for any loss, injury or inconvenience sustained by any person resulting from information published on this site. We encourage you to verify any critical information with the relevant authorities. | |
| |
|
About Us | Contact Us | Terms of Use | Privacy | Links Directory |
| 1Up Info All Rights reserved. Site best viewed in 800 x 600 resolution. |
