Bonamia grandiflora - (Gray) Hallier f.
Florida Lady's-nightcap
Other English Common Names: Florida Bonamia, Large-flowered Bonamia
Other Common Names: Florida lady's nightcap
Taxonomic Status: Accepted
Related ITIS Name(s): Bonamia grandiflora (Gray) Hallier f. (TSN 30826)
Unique Identifier: ELEMENT_GLOBAL.2.160676
Element Code: PDCON03010
Informal Taxonomy: Plants, Vascular - Flowering Plants - Morning-Glory Family
Image 10399

© Alfred R. Schotz

Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Dicotyledoneae Solanales Convolvulaceae Bonamia
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Concept Reference
Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Bonamia grandiflora
Taxonomic Comments: Distinct species, one of three in this genus.
Conservation Status

NatureServe Status

Global Status: G3
Global Status Last Reviewed: 25Jun2015
Global Status Last Changed: 12Jul1983
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G3 - Vulnerable
Reasons: A Florida endemic that is sometimes locally abundant; however, development, conversion to citrus, and the lack of fire are substantially reducing the species' natural habitat. The Florida Natural Areas Inventory's database currently contains 99 occurrence records for this species.
Nation: United States
National Status: N3

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Florida (S3)

Other Statuses

U.S. Endangered Species Act (USESA): LT: Listed threatened (02Nov1987)
Comments on USESA: Federally listed as threatened by the USFWS on November 2, 1987.
U.S. Fish & Wildlife Service Lead Region: R4 - Southeast

NatureServe Global Conservation Status Factors

Range Extent Comments: Bonamia grandiflora is a Florida endemic restricted to the xeric, white sand scrub (or its edges) in the center of the peninsula. Florida Natural Area Inventory data reports it from Hardee, Highlands, Lake, Marion, Orange and Polk Counties and it was collected in Manatee (1916), Osceola (1938), Sarasota (1878) and Volusia (1900) Counties years ago (Myint, Ward, 1968).

Number of Occurrences: 81 - 300
Number of Occurrences Comments: There are 110 occurrences in the Florida Natural Areas Inventory's database, as of August 2013.

Population Size Comments: Some populations are large where successional conditions are good. "Abundant along roadsides and rights-of-way" in the Ocala National Forest, where it occurs throughout an area about 18 miles long and 5 miles wide (USFWS 1989).

Number of Occurrences with Good Viability/Integrity: Some (13-40)
Viability/Integrity Comments: 24 populations with good viability as of 2013.

Overall Threat Impact Comments: Urbanization and citrus grove development continue to replace much of the scrub habitat in Central Florida. In the Ocala National Forest, the former management practices of clear cutting, soil tilling and close-spaced replanting of Pinus clausa seem to eliminate Bonamia (Ward, 1979). [Management practices in the ONF have been changed to favor this species, and it is now regarded as secure here (USFWS 1989).] The long-term exclusion of fire may cause a decline in the number of clearings preferred by this species. The trampling hooves of grazing cattle may also reduce the numbers of Bonamia by chopping up or uprooting the plants (Schultz, pers. obs.).

Short-term Trend: Decline of 10-30%
Short-term Trend Comments: Species has been declining primarily due to development. It has disappeared from Archbold Biological Station (USFWS 1989).

Intrinsic Vulnerability Comments: Although it invades disturbed sites, will not endure soil disturbance (e.g. grazing, soil tilling) once it is in place; requires occasional fire.

Other NatureServe Conservation Status Information

Global Range: Bonamia grandiflora is a Florida endemic restricted to the xeric, white sand scrub (or its edges) in the center of the peninsula. Florida Natural Area Inventory data reports it from Hardee, Highlands, Lake, Marion, Orange and Polk Counties and it was collected in Manatee (1916), Osceola (1938), Sarasota (1878) and Volusia (1900) Counties years ago (Myint, Ward, 1968).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map

U.S. & Canada State/Province Distribution
United States FL

Range Map
No map available.

U.S. Distribution by County Help
State County Name (FIPS Code)
FL Hardee (12049)*, Highlands (12055), Hillsborough (12057), Lake (12069), Manatee (12081), Marion (12083), Orange (12095), Osceola (12097), Polk (12105)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
03 Upper St. Johns (03080101)+, Oklawaha (03080102)+, Kissimmee (03090101)+, Western Okeechobee Inflow (03090103)+, Peace (03100101)+, Myakka (03100102)+, Little Manatee (03100203)+, Withlacoochee (03100208)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Basic Description: A perennial, trailing, herbaceous vine. Stems are prostrate, reaching 1 m or more in length. Leaves are alternate, 2.5-5 cm long. Flowers are axillary and solitary, 7-10 cm long, deep blue to purplish-blue in color.
Technical Description: "A sprawling perennial herb. Stems to 3 m long extending outward flat over the sand from a central semi-woody deep rootstock, round in cross section, short and appressed-hairy with fine, silky hairs. Leaves numerous, the blades erect or spreading firm, ovate, broadly oblong or obovate, the largest 4-5 cm long, rounded or emarginate, usually short-mucronate, the margins entire, the base usually broadly rounded or cordate, the surfaces appressed-silky-short-hairy, the petioles short, about 3 mm long, densely short-hairy. Smallest stem leaves toward stem base, the largest at about mid-stem, these grading into bracteal leaves which are along the distal 1/2-1/3 of the shoot. Inflorescence flowers solitary in the bract axils, erect on stiffish, appressed-hairy stalks mostly 1.0-2.5 cm long, these midway with a pair of erect, lanceolate, puberulent bracts around 5 mm long. Flowers with sepals 5, unequal, in 2 series, oblong, narrowly ovate or lanceolate, stiffish, erect, the apex acuminate, the margins entire, the backs pale green and covered with appressed silky hairs, the whole calyx up to 2.0-2.5 cm long. Corolla opening in early morning, closing by early afternoon, funnelform, 7-10 cm long, fully 7-8 cm across the limb, a pale but vivid blue with a paler center. Stamens 5, alternating with petal midribs, up to 5 cm long, the slender filaments with bases glandular-hairy, the anthers narrowly oblong, yellowish, about 5 mm long. Ovary superior, the style about 4 cm long, branched into 2 slender branches about midway up, each branch terminating in a small, buttonlike stigma. Fruit a capsule broadly ovoid, 1.3-1.5 cm long, with 4 valves, the walls firm but thin. Seeds smoothish, pale brown or greenish brown, 508 mm long, oblong, the outer face convex, the inner 2 flat, forming an angle" (Kral, 1983).
Diagnostic Characteristics: Bonamia grandiflora is characterized by its gray-green erect leaves, large, bluish, morning glory flowers produced from May to August, and its habit of sprawling over the scrub sand. It is the only member of its family in the scrub with large blue flowers.
Reproduction Comments: The life history of B. grandiflora has not been reported in the literature. Many seeds and some young seedlings were observed on sites with vigorous populations in August, 1983, by Gary Schultz. At one site, Bonamia was vigorously growing in a recently cleared area along a fence.

Plants grown in cultivation were observed to produce several below-ground stems from the taproot, and to spread into full sun from the partially shaded area where they had been planted (USFWS 1989).

Forms large seed banks of dormant seeds; flowering and seed production of mature plants and germination of seeds is stimulated by fire (USFWS 1989).

Ecology Comments: Florida bonamia grows in natural clearings of bare ground and invades disturbed areas of open sand. Although not common, it is often locally abundant where there is little or no shade from trees or shrubs. Allelopathy may play a part in maintaining these clearings needed by Bonamia (Richardson, 1984). The population trend of Bonamia seems to be downward as many of its previously reported sites (including Archbold Biological Station-ABS) were recently searched without finding any plants (Ward,1979). This could be due to the long term exclusion of fire allowing the woody plants to grow over natural openings (Kral,1983). David Chasteen (unpublished report on land adjacent to TNC's Tiger Creek Preserve, dated June 9, 1982) reported that Bonamia can tolerate the filtered light of a nearly closed tree canopy as long as an open shrub layer is maintained. He noted that flowering may not be as prolific, however.
Terrestrial Habitat(s): Shrubland/chaparral
Habitat Comments: Locally abundant on deep, white, dry sands of ancient dunes and sandy ridges in clearings or openings of scrub habitat on the Central Ridge of Florida.
Economic Attributes Not yet assessed
Management Summary
Stewardship Overview: 1. Manage scrub for natural canopy openings, natural canopy regeneration and minimal soil disturbance. 2. Preservation of the best existing populations of Bonamia grandiflora known in Florida.

3. Implement a program of different prescribed burning schedules at Tiger Creek Preserve.

4. Monitor results of 2.

5. Research the life history and propagation of B. grandiflora.

6. Monitor Bonamia populations existing in Florida by yearly field surveys.

Restoration Potential: Bonamia readily invades disturbed areas, provided seed sources are nearby.
Preserve Selection & Design Considerations: Consult with USFS and Fl. Div. of Forestry about management practices on ONF and Lake Arbuckle, resp.; acquire additional sites. Forty acres should be considered the minimum size for a scrub preserve but a smaller site with an exemplary population of Bonamia could be considered (Cooper, FNAI, pers. comm.). The site should have an open canopy, bare ground, and be large or secure enough to allow fire as a management tool.
Management Requirements: Active management is needed to prevent woody plant growth from shading or crowding out Bonamia. This could be accomplished by prescribed burning or thinning of the overstory (Kral, 1983).

Most of Florida's natural fires occur from June to September when lightning from thunderstorms is most abundant (Abrahamson, 1984a). Dr. Ron Myers (ABS, pers. comm. on June 20, 1984) wrote that scrub naturally burned every 20-80 years in a high intensity canopy fire that opens areas for understory species. He recommended managing for the habitat system until more is learned about individual species' requirements. He suggested varying fires both temporally and spatially rather than sticking to one set fire frequency for a particular site, as natural burning occurred whenever sufficient fuel coincided with optimum weather conditions and an ignition source. Dr. Jack Stout (UCF, pers. comm. on July 31, 1984) wrote that he thought scrub historically burned in late spring or during the winter when conditions were most dry. He felt scrub would be hard to burn during the summer rainy season. He advised having many 25 to 100 acre units of scrub at different stages in which the various scrub plants and animals could populate and reproduce.

Monitoring Requirements: Reinventory of known populations. B. grandiflora needs to be monitored wherever it occurs, as its population seems to be on the decline.

Periodic field surveys of known habitats performed on a yearly cycle.

Monitoring Programs: The FNAI should be contacted for further information. Gary Schultz searched for Bonamia in Polk and Highlands Cos. for the FNAI in August and September, 1983, and David Chasteen searched areas adjoining Tiger Creek Preserve in the spring of 1982.
Management Research Programs: Ann Johnson (1982) found (in studies at Archbold Biological Station) that Ceratiola scrub (an associated community) can be difficult to burn because Ceratiola itself is not very flammable and there is little fuel between the shrubs to carry a fire. Apparently, rosemary stands (or at least their centers) experience less frequent fires than the surrounding scrubby flatwoods. Johnson concluded that Certiola appears to be adapted to a fire cycle of (at least 10) 30 to 40 years. Warren Abrahamson (1984a) recently published some data on the results of fire on Lake Wales Ridge vegetation at ABS. He found that ridge species' populations are revitalized by fire but do not require fire in the sense of maintaining a fire subclimax. He gives data on the recovery of dominant species of 4 major vegetation associations but was unable to successfully burn sand pine or rosemary scrub (Abrahamson, 1984b).

Other knowledgeable individuals on scrub and sandhill vegetation include Dr. Jack Stout, Dr. Ron Myers, and Don Richardson. Stout is working on scrub preservation strategies in east-central Florida. Myers is studying the ecological effects of fire on Florida's sand ridges. Richardson is currently a graduate student at USF in Tampa exploring the effects of allelopathy in the Florida scrub. (FNAI is the most informed on occurrences and distribution of rare plant species in Florida.)

Management Research Needs: Need to monitor the results of different prescribed burning schedules varied both spatially and temporally on the growth and reproduction of Florida bonamia. Also, its life history and propagation should be investigated.
Population/Occurrence Delineation Not yet assessed
Population/Occurrence Viability
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
NatureServe Conservation Status Factors Edition Date: 15Aug2013
NatureServe Conservation Status Factors Author: GARY SCHULTZ, FLFO (1986); rev. M.E. Stover, TNC-HO (2/95), rev. Amy Jenkins (2013)
Management Information Edition Date: 17Feb1986
Management Information Edition Author: GARY SCHULTZ, FLFO
Element Ecology & Life History Edition Date: 17Feb1986
Element Ecology & Life History Author(s): GARY SCHULTZ, FLFO; REV. M.E. STOVER, TNC-HO (2/95).

Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

  • Abrahamson, W.G. 1984a. Post-fire recovery of Florida Lake Wales Ridge vegetation. American J. Botany 71(1): 9-21.

  • Abrahamson, W.G. 1984b. Species response to fire on the Florida Lake Wales Ridge. American J. Botany 71(1): 35-43.


  • Clewell, A.F. 1985. Guide to vascular plants of the Florida panhandle. Florida State Univ. Press, Tallahassee, Florida. 605 pp.

  • Duever, L.C. 1983. Natural communities of Florida's inland sand ridges. Palmetto 3(3): 1-3.

  • Hall, D.W. 1993. Illustrated plants of Florida and the Coastal Plain. Maupin House, Gainesville, Florida. 431 pp.

  • Hall, David W. 1993. Illustrated plants of Florida and the coastal plain. Maupin House, Gainesville, FL. pp. 431.

  • Johnson, A.F. 1982. Some demographic characteristics of the Florida rosemary, Ceratiola ericoides. American Midland Naturalist 108:170-174.

  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Kral, R. 1983c. A report on some rare, threatened, or endangered forest-related vascular plants of the South. U.S. Dept. of Agriculture Forest Service Technical Publication R8-TP2, Athens, GA. 1305 pp.

  • Myint, T., and D.B. Ward. 1968. A taxonomic revision of the genus Bonamia (Convolvulaceae). Phytologia 17(3): 121-239.

  • Prance, G.T., ed. 1977. Extinction is forever. New York Botanical Garden, New York.

  • Richardson, D.R. 1984. Allelopathy in the Florida scrub. Paper presented at Florida Native Plant Society's Fourth Annual Conference, Fl. Atlantic University, Boca Raton, May 4, 1984.

  • Small, J.K. 1933. Manual of the southeastern flora. Two volumes. Hafner Publishing Company, New York.

  • Taylor, W.K. 1992. The guide to Florida wildflowers. Taylor Publishing, Dallas, Texas. 320 pp.

  • Taylor, Walter Kingsley. 1992. The Guide to Florida Wildflowers. Taylor Publishing Company, Dallas, Texas. 320 pp.

  • U.S. Fish and Wildlife Service. 1989. Recovery plan for eleven central Florida scrub plants. U.S. Fish and Wildlife Service, Atlanta, Georgia. 64pp.

  • Ward, D.B., ed. 1979. Rare and endangered biota of Florida. Vol. 5: Plants. Univ. Presses of Florida, Gainesville.

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