What Are The Medicinal Uses Of Tillandsia Usneoides Medicinal

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Source: After Benzing (1990).

Source: After Benzing (1990).

local bromeliads and epiphytic orchids (Table 6.11). Conversely, Ficus aurea failed to nurture even one of the hundreds of seeds glued to its smooth, stable bark over the four-year survey, perhaps for the same reason that extracts of this tree inhibited germination of the orchid Encyclia tam-pensis in another study (Frei and Dodson 1972). Bursera simaruba, at best an occasional substrate for Florida Bromeliaceae, and then only in cracks and knotholes, regularly shed bark in small fragments, often with test subjects attached (Fig. 7.7F). Both Bursera and Ficus retain considerable foliage most winters in Florida, rendering their crowns darker and therefore even less suitable for heliophilic Tillandsiapaucifolia than those of fully deciduous cypress. Controls affixed to cedar lathe and maintained under a daily greenhouse mist regimen germinated at >90% during each of the four years.

Tillandsia paucifolia seeds performed much as they had in situ while attached to 6 9 cmX 0.5 m sections of limbs following the technique utilized for securement to trees in Florida. Examined supports included Taxodium, two occasional phorophytes (Rhizophora mangle and Conocarpus erecta) and Bursera simaruba. Timers activated a misting system for 30 min every 1,2,4 and 6 days, after which bark surfaces bearing seeds air-dried within 3 4 h and even sooner on sunny days. Between 6 and 35% of the 100 seeds representing each treatment germinated within 14 days (Table 6.12). Except for those on Rhizophora, which experienced fairly consistent success, seeds performed best under the three wettest regimens.

Growth following germination also measures performance, and dryness depressed epiphyte vigor on all four of the tested phorophytes. Subjects irrigated just once every sixth day grew to only 10 20% the size of those

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Figure 6.9. Survivorship among four cohorts of Tillandsiapaucifolia seedlings that had germinated while glued to the bark of Taxodium distichum in south Florida (after Benzing 1990).

individuals subjected to the two wettest treatments. Seedlings misted every fourth day grew somewhat faster, but only at about half the rate exhibited by subjects moistened each or every other day. Persistent seed coats and intertwining coma hairs precluded more precise quanti cation of seedling size (Fig. 6.5G).

Survivorship

Two techniques served to document the life history of T. paucifolia in Florida: continued surveillance of the year-old survivors of the seed germination exercise, and censuses of naturally established colonies occupying other Taxodium distichum specimens in the same region (Benzing 1978b, 1981a). Results from one site in the Big Cypress National Preserve exemplify those for the entire sample (Fig. 6.9). Each spring from 1978 through 1981, 480 seeds had been sown on the trunks or large limbs of the same 10 trees. Revisits the following year revealed survivors in every cohort, although 1979 brought the greatest success (Fig. 6.5E). Here, as at all the other sites that witnessed some germinations, survival increased dramatically following heavy mortality during the rst few years of life. Dried remains de ed determinations of causes, which were probably drought, frost or pathogens. Other seedlings simply vanished. No plants owered during the experiment, although several eight-year-olds appeared close to maturity on the last visit. Uneven growth, presumably related to site quality and competition among survivors in the same test patch, caused the sizes of equal-aged plants to differ several fold.

Tillandsia paucifolia anchored on randomly felled, 85 200-year-old dwarfed cypress trees in a single, mixed Pinus/Taxodium forest provided the life table data illustrated in Fig. 6.8. Values recorded for each year represent plants distributed among 10 15 cypress crowns harvested during each of three consecutive winters. Mean numbers of residents per tree differed among years in part because epiphyte density varied systematically across the sampled forest. However, apportionments among the age/size classes remained fairly constant. Phorophyte age determined by growth rings failed to predict the demographic structures of the resident colonies of bro-meliads.

Categories A (de nite rst-year seedlings) and H I (adults), more age-diverse groups, usually contained fewer individuals than those between A and H (Fig. 6.8). When numbers exceeded 10 per phorophyte (Table 6.13; tree number 6), most young of the year clustered within a meter or so of a putative maternal parent a plant that had fruited the previous season. However, the presence of a plant (or plants) with a spent infructescence in a crown one winter did not assure the occurrence of yearlings there the next. During the 1979/80 and 1980/81 seasons, 99 of 116 new recruits on 20 trees possibly originated from one or more post-fruiting adults sharing the same support. Those 17 others must have been fugitives, up to ve on a single tree, that arrived from parents in other crowns.

Two trees that harbored fruiting individuals in 1978 or 1979 supported no one-year-old seedlings the next season, whereas other trees with the same history bore 1 36 such juveniles. Plant structure that indicates how many fruits had been produced on an infructescence deteriorates too quickly to estimate the size of a seed source, which in the area studied could be just one capsule per plant to about 20. The largest specimens harvested for the survey were ripening up to 12 capsules, with less than three as the average. During 1981, the only year that seeds were counted, 11 fruiting specimens yielded 15 capsules containing in all about 1500 seeds.

Category B juveniles, second-season young perhaps augmented by the occasional slow-growing third-year seedling, remained aggregated and numerically diminished compared with those of category A. Little clustering remained among specimens large enough to qualify for category C. Here, larger numbers and more uniform occurrences among hosting crowns re ected additional convergence by plant size involving parts of four to ve, perhaps even more, successive cohorts. Reduced numbers of

Table 6.13. Age structure of colonies of Tillandsia paucifolia on 10 dwarfed Taxodium distichum trees determined in

January 1980

Host number

Table 6.13. Age structure of colonies of Tillandsia paucifolia on 10 dwarfed Taxodium distichum trees determined in

January 1980

Host number

category (mm)

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