Agoseris grandiflora, commonly known as bigflower agoseris, grassland agoseris, or sometimes California dandelion, is a flowering plant in the Asteracae family.
- Agoseris laciniata
- Stylopappus grandiflorus
- Agoseris cinerea
- Agoseris grandiflora (Nutt.) Greene var. intermedia
- Agoseris grandiflora (Nutt.) Greene var. plebeia
- Agoseris intermedia
- Agoseris laciniata
- Agoseris marshallii
- Agoseris obtusifolia
- Agoseris plebeia
- Stylopappus grandiflorus Nutt.
- Kingdom Plantae – Plants
- Subkingdom Tracheobionta – Vascular plants
- Superdivision Spermatophyta – Seed plants
- Division Magnoliophyta – Flowering plants
- Class Magnoliopsida – Dicotyledons
- Subclass Asteridae
- Order Asterales
- Family Asteraceae – Aster family
- Genus Agoseris Raf. – agoseris
- Species Agoseris grandiflora (Nutt.) Greene – bigflower agoseris
Scapose, stout perennial, 2-7 dm. tall, somewhat hairy when young, the juice milky, with basal, oblanceolate to broadly linear pinnatifid leaves (10-25 cm. long and 1-3 cm. wide. Large flower head with many yellow flowers, involucre 1.5-4 cm. high, its outer bracts broad and short, the inner narrower and elongate; corollas all ligulate. Produces fruits with achene body 4-7 mm. long, tapering to a slender beak 2-4 times as long. 
West of the Rocky Mountains 
Meadows and other open places in the lowlands and at moderate elevations in the mountains, often in dry areas. 
Seed sample from: 2010
Average Measurement: 5.2 x 0.7 x 0.7
Measurement Range: L: 4.6 - 6, W: 0.5 - 0.9, D: 0.5 - 0.9
Shape: Seeds tapering to a beak 2-3 times as long as the body of the seed.
Color: Seeds pale brown with white, glossy hilum.
Additional Structures: Pappus white, and downy.
Surface: Seed body deeply longitudinally grooved. Ridges are finely toothed. Seed slightly glossy.
Basic Explanations and Assumptions:
The dimensions for the seeds are length x width x depth. The location of the hilum is used as the base of the seed, and the length is measured from hilum to the opposite apex. Where a style is present, the length is measured from the hilum to the bottom of the style. Width is measured at a right angle to the length at the widest part. Depth is measured at a right angle to the intersection of height and width lines.
Measurements included are the mean average for each measurement of ten separate seeds.
All measurements in millimeters unless otherwise noted.