FDACS DPI Tri-ology March - April 2010: Botany Section

	Mar/ Apr	Year to Date
Samples submitted by other DPI sections	1,076	2,058
Samples submitted for botanical identification only	100	194
Total Samples Submitted	1,176	2,252
Specimens added to the herbarium	27	37

Botany Section

Compiled by Richard E. Weaver, Jr., Ph.D., and Patti J. Anderson, Ph.D.

This section identifies plants for the Division of Plant Industry, as well as for other governmental agencies and private individuals. The Botany Section maintains a reference herbarium with over 10,000 plants and nearly 1,400 vials of seeds.

Abutilon chittendenii Standl. (canary tree), a genus of approximately 100 species widely distributed in tropical and subtropical regions, with a few weedy annuals in more northern areas. Malvaceae. This native of Guatemala and Honduras is rare in cultivation and is sometimes listed as Bakeridesia integerrima (Hook.) D.M. Bates. It is a showy and handsome tree growing about 3 m tall, with evergreen, broadly heart-shaped, entire-margined leaves that are 8-15 cm long and about as wide. They are pubescent with stellate hairs and are rough to the touch on the upper surface. The flowers are 5-8 cm across and resemble those of a hibiscus. The five petals are bright yellow, each with a reddish blotch at the base. The stamens are fused into a tube by their filaments, as is typical of the Mallow Family. The distinctive, rough-hairy fruits are made up of 14 or so segments which radiate like the spokes of a wheel. These fruits become papery as they mature and dehisce along their upper edge. This evergreen, ever-blooming plant is unfortunately rarely offered for sale here in Florida. It is an excellent tree for container culture or for a small garden, doing best with full sun and good drainage. In Florida, it should be root-hardy as far north as Ocala. (Pinellas County; B2010-164; Gabriela M. Bernard, 8 April 2010.) (Mabberley 1997; Standley and Steyermark 1949.)

Physalis philadelphica Lam. (Mexican groundcherry, tomatillo), a cosmopolitan genus of 80 species. Solanaceae. This species, native to Mexico, is an annual to 60 cm tall. The alternate, ovate leaves have entire to dentate margins, acute to slightly acuminate apices, and are about 4x10 cm in size. Flowers are borne singly with a five-lobed calyx that becomes papery and inflated as the fruit develops. The yellow, 8–15 mm wide corolla has dark maroon to purple splotches in the throat. Anthers are blue-green and twisted at maturity. The fruit is a globose, pale green to purplish berry 2.5-6 cm across. Although this species is in the same family as the garden tomato, Lycopersicon esculentum, and is sometimes called “green tomato,” it is not a tomato. The plant can be weedy, but it is also planted as a food crop, popular in Mexican cuisine as the basis for salsa verde, usually in combination with green chili peppers. (St. Lucie County; B2010- 146; Dagne A. Vasquez; 30 March 2010.) (Huxley 1992; Morton 1987.)

Polygala myrtifolia L. (sweet-pea shrub, African milkwort), a cosmopolitan genus of nearly 100 species. Polygalaceae. This unusual shrub is adapted to a wide range of climatic conditions in its native South Africa, growing in both summer-rainfall and winter-rainfall areas. Not surprisingly, it is quite variable. It can be an evergreen shrub to 2 m tall, or a small tree to 4 m tall; the leaves can be thick and oval or thin and needle-like; and the color of the flowers varies from mauve or purple to pink, scarlet or white. In cultivation, it grows best in Mediterranean-type climates, with rainfall in the winter, and it has escaped and become invasive in such climates in southern Europe and southwestern Australia. Plants of the genus Polygala are often known as milkworts, since ingesting them reputedly increases lactation in cows. These plants have unusual and showy flowers that resemble those of legumes, with two wing petals and a keel; Polygala flowers, however, lack a standard (or banner) petal, and the tip of the keel is ornamented with a distinctive, brush-like tuft of fleshy hairs. Despite the floral similarities, the Polygalaceae and the Leguminosae are not closely related. The sweet-pea shrub is an attractive plant, with its neat, evergreen foliage somewhat resembling that of the myrtle (Myrtus communis), but with alternate leaves. The flowers are about 2 cm across, usually pink or purplish in our plants, with a strong superficial resemblance to those of the sweet pea (Lathyrus odoratus). The plant is rare in cultivation in Florida, and there is no evidence that it has escaped and naturalized, but since it is invasive elsewhere, it should be carefully monitored. (Miami-Dade County; B2010-183; Olga Garcia, 20 April 2010.) (http://www.plantzafrica.com [accessed 12 May 2010].)

Selaginella kraussiana (Kunze) A. Braun. (Krauss’ spikemoss), a genus of more than 700 species, mostly native to the tropics and subtropics, with a few species in the temperate zones. Selaginellaceae. Spikemosses are primitive land plants that have vascular tissue and reproduce by means of spores rather than seeds. They are most closely related to clubmosses (Lycopodium) and quillworts (Isoetes) and more distantly to ferns. They are entirely herbaceous, mostly small in stature, and generally minor components of the vegetation types in which they occur. The spore-bearing organs are borne in the axils of specialized leaves, and these are arranged in conelike structures termed strobili (singular strobilus) at the tips of the branches. Spikemosses superficially resemble true mosses, but the groups are not closely related. Mosses are much more ancient, they lack vascular tissue and their spores are borne in (simplistically speaking) capsule-like structures on long stalks from the tips of the shoots. Selaginella kraussiana is native to southern Africa, but it has naturalized in various areas around the world, including the British Isles and New Zealand. It is reported to be invasive in the latter country. In the United States, it has been reported from several areas in the Southeast (not Florida, yet), and from California. It is a creeping, mat-forming plant usually less than 10 cm tall. The tiny leaves are arranged in four rows on the prostrate stems, covering them like shingles, much like those of junipers and related conifers. It is cultivated as a house plant, or in a shady garden in milder climates. Several cultivars are popular, including ‘Aurea’ and ‘Chartreuse’ with yellowish foliage, and ‘Brownii,’ a compact form which grows into ball-like clumps. (Orange County; B2010-181; Lance A. Brown, 19 April 2010.) (Valdespino 1993.)

Soliva sessilis Ruiz & Pav. (field burrweed, lawn burrweed), a genus of eight species from South America. Compositae/Asteraceae. This weedy species is widely distributed in North America, in the Southeast from Virginia to Texas and in the Southwest from Arizona along the Pacific coast to British Columbia. In Florida, it is found mainly in the Panhandle and in a scattering of peninsular counties north of Lake Okeechobee. This lawn weed is a low-growing annual with fibrous roots; purplish, prostrate or ascending stems to 10 cm tall, often rooting at nodes; and pinnately dissected, alternate leaves. The inflorescence is a sessile head composed of small, inconspicuous greenish flowers with disc, but not ray, florets. The fruit is a spiny, 2-3 mm long achene which inspires the common name, burrweed. Each achene has lateral wings that become spine-like at the tips on either side of the persistent style which forms a larger central spine. This species grows in disturbed sites and on lawns and roadsides, often out competing lawn grass and perhaps being easier to identify with bare feet than by sight. The plants survive mowing and grazing, but might be controlled with herbicides. (Jefferson County; B2010-185; Michael A. Bentley; 15 April 2010.) (Wunderlin and Hansen 2003; http://www.ipm.ucdavis.edu [accessed 25 May 2010]; http://plants.usda.gov [accessed 25 May 2010].)

Tillandsia recurvata (L.)L. (ball moss), a genus of about 380 tropical American species. Bromeliaceae. This epiphytic species is found in Florida and Georgia and from Louisiana to Arizona as well as Mexico, the West Indies, Central America and South America. In Florida, it has been reported throughout the peninsula, but in only a scattering of counties in the Panhandle. The plant grows in dense clusters, not hanging down from its support like the related Spanish moss (Tillandsia usneoides). The stems are very short, without the pseudobulb or tank found in some bromeliads, and there are no true roots. The grayish, succulent leaves are alternate, 5-15 cm long, recurved and densely covered with silvery trichomes. The inflorescences are erect spikes holding one to several tubular flowers with pale blue to violet petals. The fruit is a three-parted capsule containing numerous wind-dispersed seeds. Although the common name of this species suggests otherwise, this plant is not a moss, but an unusual flowering plant with the ability to survive not only growing on other plants, but also festooning power lines and bare rocks in arid areas. The trichomes that cover its leaves are attached at a central point, with overlapping margins covering the entire leaf surface. These silvery scales absorb water and provide habitat for micro-organisms. The microflora found living upon this epiphytic bromeliad includes several species of nitrogen-fixing bacteria. The plant (or wire) on which the ball moss cluster rests provides only physical support, not water or nutrients. Still, a massive cluster of T. recurvata could cause harm to a supporting plant by blocking sunlight or breaking branches. This species has been investigated for medicinal properties, especially anti-tumor and anti-inflammatory activity. (Palm Beach County; B2010-186; Antonio I. Perez; 19 April 2010.) (Brighigna et al. 1992; Puente and Bashan 1994; http://www.efloras.org [accessed 25 May 2010]; http://www.patents.com/Anti-tumor-anti-inflammatory-extracts-plant-biomass-uses-7713556.html [accessed 25 May 2010].)

References

Brighigna, L. P. Montaini, F. Favilli and A. C. Trejo. 1992. Role of the nitrogen-fixing bacterial microflora in the epiphytism of Tillandsia (Bromeliaceae). American Journal of Botany 79: 723-727.

Huxley, A.J. (editor). 1992. The new Royal Horticultural Society dictionary of gardening. 4 volumes. Macmillan Press, London, England. 3,240 p.

Mabberley, D.J. 1997. The plant-book, 2nd edition. Cambridge University Press, Cambridge, England. 858 p.

Morton, J.F. 1987. Fruits of warm climates. Julia F. Morton, Miami, Florida. Distributed by Creative Resources Systems, Winterville, North Carolina. 505 p. Text available on-line at http://www.hort.purdue.edu/newcrop/morton/index.html [accessed 25 May 2010].

Puente, Maria-Esther and Yoav Bashan. 1994.The desert epiphyte Tillandsia recurvata harbours the nitrogen-fixing bacterium Pseudomonas stutzeri. Canadian Journal of Botany 72: 406–8.

Standley, P. C. and J.A. Steyermark. 1949. Abutilon, in Flora of Guatemala, Fieldiana: Botany 24: 326-335.

Valdespino, I.A. 1993. Selaginellaceae, in Flora of North America 2: 38-63.

Wunderlin, R. P. and B. F. Hansen. 2003. Guide to the vascular plants of Florida, 2nd edition. University Press of Florida, Gainesville, Florida. 787 p.

Sample Submissions

Botany Section

References