Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Valdes, Imena [1], Acevedo, Christian [2], Hawthrone, Tawny [3], Finch, Jessamine [4], Havens, Kayri [5].

When is a native not a native? Preliminary results of pollinator support of native plants and their cultivated varieties in Penstemon digitalis.

Native plants are being brought into cultivation at an increasing rate and are getting modified for better horticultural performance and appearance. The cultivated varieties of natives, also termed ‘nativars’, are now common sites in nurseries and the garden section of home improvement stores as they are being used broadly in horticulture and sometimes in restoration. As a result, vast numbers of nativars are spreading across many ecosystem types and may outnumber their wild relatives. This is particularly true in urban areas which may serve as important refugia for pollinator species. In selecting for horticulturally desirable traits (e.g. novel floral form, color, phenology), the floral attractants and rewards may have been altered or diminished. It is important to examine the relative support of these nativars as compared to their wild relatives.
In the summer of 2019, Penstemon digitalis and a representative selection of their nativars (‘Husker Red’, ‘Pocahontas’, Blackbeard’) were studied. The floral trait variation and pollinator support was compared and preferences of different groups of floral visitors was determined through monitoring of phenology, pollinator observations, and floral trait measurements. The next step is to evaluate the impact of floral trait differences and pollinator visitation on reproductive fitness will be evaluated.
We found that all Penstemon have roughly the same first and end flower times, and peak between 180 to 185 days. When there is a larger number of flowers, there is a corresponding peak in pollinator visitation. Both wild type and ‘Pocahontas’ have more open flowers and receive a higher average of pollinator visits per minute compared to the other species. Floral morphology is a distinct factor in pollinator diversity. Smaller flowers, such as ‘Blackbeard’ and ‘Husker Red’, attract small bees and flies whereas the larger flowers, wild type and ‘Pocahontas’, attract more bumblebees, large bees, and wasps due to a pronounced size difference. These results suggest that pollinator visitation varies between Penstemon digitalis and its nativars as a result of flower size. The nativar ‘Pocahontas’ attracted roughly the same number of pollinators as the wild type, while ‘Husker Red’ and ‘Blackbeard’ received roughly half as many visits.

1 - Northwestern University , Plant Biology and Conservation, 2205 Tech Drive, O.T. Hogan Hall, Room 6-140B, Evanston, IL, 60208, USA
2 - Miami Dade College, School of Science, 11380 NW 27th Ave, Miami, FL, 33167, USA
3 - Alcott College Prep High School , 2957 N. Hoyne Avenue, Chicago, IL, 60618, USA
4 - Native Plant Trust, Conservation, 180 Hemenway Road, Framingham, MA, 01701, USA
5 - Chicago Botanic Garden, CONS SCI DEPT, 1000 Lake Cook Road, Glencoe, IL, 60022, United States


Presentation Type: Poster
Session: P, Symbioses: Plant, Animal, and Microbe Interactions Posters
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 5:00 PM Time and date to be determined
Number: PSM003
Abstract ID:136
Candidate for Awards:None

Copyright © 2000-2020, Botanical Society of America. All rights reserved