Geranium bicknellii
 
Bicknell's Geranium

Early Schizocarp Cut Open

Hudson Bay Airport Road
08-July-2024

As the fruit develops, the central portion of the receptacle elongates into a long, narrow cylinder called the columella. In addition, the styles of the five carpels elongate into five long beaks called rostra. The rostra are initially attached lengthwise to the columella. When the fruit is mature, each carpel (now known as a mericarp) and the proximal portion of the rostrum detach and coil away from the columella. During this process, the seed is ejected from the mericarp. The entire structure is called a schizocarp.

Three of the five sepals have been removed form this specimen. The rostra are still attached to the columella.

Bicknellii: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species.  

plant annual or biennial; NOT [plant perennial, with rootstocks or caudices]

inflorescence loose; NOT [inflorescence compact]

fruiting pedicels much longer than the calyx; NOT [fruiting pedicels shorter than to slightly longer than the calyx] 

flowers NOT over 12 mm across

sepals broadly lanceolate to oblong-ovate; NOT [sepals broadly ovate]

sepals bristle-tipped

petals scarcely longer than sepals; NOT [petals much longer than sepals]

petals 2-8 mm long; NOT [petals 1-2 cm long]

beak of mature style column 3-5 mm long; NOT [beak 1-1.5 mm long]

seeds rough; NOT smooth

 

Geranium: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.

leaves palmately lobed or divided; NOT [leaves pinnately lobed or dissected]

leaves palmately veined; NOT [leaves pinnately veined]

anthers 10; NOT [anthers 5]

stylar parts merely recoiled at dehiscence and glabrous within; NOT [stylar parts spirally twisted at dehiscence and bearded within]

capsule (mericarp) round; NOT [capsule spindle-shaped]

 

Geraniaceae: Answers to key questions in Budd's Flora leading to this family.

herbs; NOT [shrubs or trees]

plants terrestrial or semiaquatic; NOT [plants aquatic with leaves submerged or floating]

plants NOT with colored milky juice

plants with more than one normal leaf

leaves with stipules

leaves palmately divided; NOT [leaves with 3 leaflets]

flowers with two floral rings

flowers, including calyx, regular in shape

each petal distinct from the others

stamens usually separate or partly so; NOT [stamens in a column]

stamens 5 or 10; NOT [stamens usually numerous]

ovary of 5 united carpels; NOT [ovary of one or more carpels, either separate or enclosed by a fleshy receptacle]

fruit with a long beak