Abstract Detail

Developmental and Structural Section

Borgardt, Sandra Jean [1].

Pistillate Floral and Fruit Development in Quercus palmeri, an intermediate oak (Fagaceae).

The first anatomical study of pistillate flowers and fruits of subgenus Quercus section Protobalanus is presented. A developmental series was collected over a single growing year from two wild trees of Quercus palmeri Engelm. and thin sectioned using glycol methacrylate embedding and glass knife techniques. Pistillate flowers of a current growing year, each consisting of a pistil with three short, broad styles, six basally fused tepals in two alternating cycles, and an inconspicuous ovary subtended by a few cycles of cupule scales, emerged in early May. Pollination occurred by mid-May followed by quiescence for the remainder of the current growing year, with three locules delimited by septa discernible in the ovary at the end of the year. Flowers from the previous growing year resumed growth in early May, each forming two bitegmic, epitropous ovules in each locule. Mature embryo sacs were present by mid-June of the second growing year, with embryos observed thereafter. Fruit maturation was complete by early August. New features for section Protobalanus and/or subgenus Quercus that may have phylogenetic implications include: stigmatic surfaces restricted to apex of styles, a perianth flange, presence of staminodia, persistent septal remnants at maturity, and no cupule scale primorida produced during second growing year. A comparison of flower and fruit developmental features in Q. palmeri with sections Quercus s. s., Cerris, and Lobatae reveal a mosaic of shared features among the four sections of Quercus subgenus Quercus.

Broader Impacts:

1 - Cornell University, Plant Biology, 105 Woods Edge Dr, Painted Post, NY, 14870, USA

Keywords:
aborted ovules
acorn
Protobalanus
Quercus
flower
fruit
seed.

Presentation Type: Oral Paper:Papers for Sections
Session: 26
Location: Jasperwood/Riverside Hilton
Date: Tuesday, July 30th, 2013
Time: 11:00 AM
Number: 26004
Abstract ID:821
Candidate for Awards:None