Leaves

Aconitum delphinifolium is a deciduous perennial plant that grows rapidly in the spring using the nutrition stored in its roots, this allows it to fully develop its leaves before many other plants. Its leaves are palmately divided into usually 5 segments with each segment being again divided into multiple segments giving it a needlelike appearance. 

http://www.flora.dempstercountry.org/V.B.08.Ranunculaceae/Aco.delphi/Aco.delphi.pic4.jpg

The deeply divided leaf shape is a common characteristic of many plants growing in cold and arid environments. Possible adaptation to improve hydraulic efficiency?  They are alternately arranged with the lowest leaves being the largest (25 cm), and extend from the stem by long petioles. Upper leaves tend to be smaller (5cm) and are often attached directly to the stem lacking a petiole (CYSIP). 

http://analogicalplanet.com/Pages/ContentPages/Vascular%20plants2/AconitumDelphinifolium.html

This adaptation likely allows the plant to capture the most sunlight with the fewest amounts of leaves. All of the leaves tend to be hypostomatic with the majority of their stomates located on the bottom (Stanescu et al, 2009). The alkaloid aconitine is found in the leaves which may aid as a deterrent to herbivory. 

References

CYSIP. "Aconitum Delphinifolium : Northern Monkshood." Flora.dempstercountry.org. Central                     Yukon Species Inventory Project, n.d. Web. 5 Feb 2014.

Stanescu, I., C. Mardari, and C. Tanase. "Notes on the morpho-anatomy of Aconitum degenii gayer." Biologie Vegetala, 2009: 55-63.