Demography and habitat of Corydalis flavula (Raf.) DC. (Fumariaceae) in south-western Michigan (U. S. A.)1

Nuzzo V (Natural Area Consultants, 1 West Hill institute Road, Richford, NY 13835). Demography and habitat of Corydalis flavula (Raf.) DC (Fumariaceae) in south-western Michigan (U s A.). J. Torrey Bot. Soc 132: 16-23 2005.-Corydalis flavula (Raf.) DC is a rare winter annual in Michigan, restricted to sum of two units counties in the southwestern portion of the state. Corydalis flavula density, capsule and se production, and composition and configuration of the associated groundlayer and overstory, were recorded 18-26 May 1998 in six 5600 m^sup 2^ piece of grounds Corydalis flavula plants were sparsely dispersed, averaging 14 plants/m^sup 2^ and 11% overlay in all plots. Over 95% of C flavula plants produc flowers, and 89% produc semens Flowering plants produced an average of 40 capsules, each with an average of 38 sperms and seed production averaged 151 seeds/flowering plant, and 199 seeds/m^sup 2^ above 11% of plants were brows by the agency of deer, foliage on 3.4% of plants showed insect feeding damage, and 37% of capsules showed external attack. Inside capsules, insect attack was more oft-repeated averaging 11%. The six stands where C flavula was monitored were relatively similar: young, next to the first growth, disturbed forests, dominated through black locust (Robinia pseudoacacia L) and subdominated by the agency of black cherry (Prunus serotina Ehrh) Tree density ranged from approximately 750-1250 trees/ha, and dead tree were for the use of all accounting for an additional 28% of all tree > 10 cm dbh Corydalis flavula vicinity was associated with shorter groundlayer vegetation (25 cm v 29 cm) and lower groundlayer overspread (96% vs 107%), and abundance was significantly higher in one as well as the other quadrats and plots with depressed graminoid cover and high annual and biennial overspread Corydalis flavula, like other woodland annuals, is disturbance adapted, and conditions that favor growing of woodland annuals also favor the extension of C. flavula.

Key words: Corydalis flavula, Robinia pseudoacacia, forest understory, winter annual

Corydalis flavula (Raf.) DC (Fumariaceae) is a winter annual that be met withs from New York and Ontario west to southerly Dakota, and south to North Carolina and Oklahoma. While public within the center of this range, C flavula is rare along the northern perimeter. A threatened species in Michigan, C flavula is known from solitary two locations: the Fort Custer Training Center (FCTC) and the adjacent Fort Custer Recreation Area and Veteran's National graveyard (Higman 1996), both located in southwestern Michigan.

Corydalis flavula is a thin semi-succulent winter annual with a nine month life span. sperms germinate in late summer (Baskin and Baskin 1994) and plants overwinter as seedlings and be exposed to rapid growth in early spring, reaching an average height of 10-30 cm Foliage is virid to glaucous and finely pinnatisect (Hill 1992) Plants bring forward 10 mm long yellow flowers in racemes in April and early May, and plant seeds in 1.5-2 cm lengthy capsules in late May and early June and then senesce (Hill 1992) The majority of semens are presumed to germinate within three month on the other hand buried seeds can remain viable for up to 5 years (Baskin and Baskin 1994) The Corydalis genus, which consists of 10 species in the United States and > 400 species world-wide (Wu et al. 1996) has been extensively studied. Related species are insect pollinated (Ohara and Higashi 1994 Olesen 1996 Maloof 2000) and ant dispersed (Nakanishi 1994 Ohkawara et al. 1997) In the absence of pollinators, C flavula self-pollinates (Macior 1978) on the other hand little else is known about C flavula life history or habitat requirements. Like many of the annual Corydalis, this species appears to be intolerant of intense competition from other species, and is presum disturbance adapted (Swink and Wilhelm 1994) Corydalis flavula typically present itselfs in moist forest (flood plain, moist thickets, groveed riverbanks, swampy ground) and infrequently in drier locations (Vos 1985 Gleason and Cronquist 1991 Hill 1992) This close attention was conducted to obtain baseline demographic and habitat data about C flavula in Michigan.

Method and Materials. SITE. Fort Custer Training Center (FCTC) is a 3063 ha National Guard training facility located upon federal land in Kalamazoo and Calhoun Counties, lower Michigan. The site is located upon a rolling, coarse textured extreme point moraine, with glacial outwash sand and gravel deposits upon the northern boundary. The majority of the site has been altered by dint of historic landuse, including farming and logging, and by the agency of contemporary military training uses, including tank maneuvers, large and small arms target practice, missile training, and bivouac and compass course training.

STUDY piece of ground LOCATIONS. Thirteen populations of C flavula were recorded during a two-year floristic view (Legge et al. 1995) and tread on the heels of up study (Higman 1996) of FCTC All populations occurr upon Oshtemo sandy loam soil (Fort Custer Soil Inventory 1997) near unpaved roads, and twelve were in second-growth Robinia pseudoacacia L (black locust)-Prunus serotina Ehrh (black cherry) stands. All populations were inspected 18 May 1998 and six were pick outed for monitoring based on spatial distribution within FCTC (select sites were ?‰? 10 km apart) and within the local area (select populations overlayed > 500 m^sup 2^).