Aster laevis

      
Smooth Aster

Basal Leaf Bottom

5 Miles East of McLean
26-Aug-2005

Note that the leaf does NOT have a cordate base.

The characteristics of the leaves and petioles are important in distinguishing between the Aster species of the Canadian prairies.  The key to the species in Budd's Flora requires the following of A. laevis:

bullet

leaves clasping

bullet

basal and lower stem leaves sessile or subsessile; NOT [basal and lower stem leaves petioled or narrowed to a petiolar base]

The key to the species in Flora of Alberta requires:

bullet

lower leaves linear, lanceolate or oblanceolate, mostly sessile or nearly so; NOT [lower leaves long-petioled, blades ovate to lanceolate, often cordate at base, serrate to serrulate]

bullet

lower leaves wing-petioled, the upper auriculate-clasping

In fact, the leaf and petiole characteristics vary depending upon the leaf location.  The basal leaves (if present) and lowest stem leaves are petioled but not cordate.  Further up the stem, the leaves narrow to a winged petiole.  The upper stem leaves are sessile and often auriculate-clasping.  The rest of the key answers are listed below.

bullet

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

plants perennial, with rootstocks or root crowns; NOT [plants annual, with fibrous roots]

bullet

NOT [plants 50 cm tall, or more; stem stout, usually crimson-purple, hispid; leaves oblong to lanceolate, auriculate-clasping, entire or distantly serrulate]

bullet

plants glabrous, except sometimes in the inflorescence; NOT [plants pubescent on the stem and branches in lines decurrent from the leaf bases]

bullet

leaves glaucous

bullet

involucres and peduncles NOT glandular

bullet

heads few to many on a stem; NOT [heads solitary or 1-3 on a stem]

bullet

involucral bracts generally herbaceous, at least above, usually not keeled; NOT [involucral bracts chartaceous, keeled, often crimson-edged]

bullet

NONE of the outer bracts foliaceous

bullet

outer bracts NOT surpassing the inner; NOT [equaling or surpassing the inner]

bullet

bracts linear, lanceolate or oblong, all acute; NOT [bracts oblanceolate, the outer obtuse, appressed, well imbricate]

bullet

bracts mostly glabrous except the ciliate margins; NOT [bracts densely pubescent]

bullet

rays conspicuous

bullet

rays mostly more than 15; NOT [rays 8-15, mostly 13, about 2 cm long, white or pinkish]

bullet

pappus single; NOT [pappus double, the inner series of long bristles, the outer of bristles about 1 mm long]

 

bullet

Aster: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus. The answers do not match all species of Aster found in the Canadian prairies, but they do match this species.
bullet

taproot absent

bullet

juice watery; NOT milky

bullet

plants usually with leafy stems; NOT [ plants low, stemless, tufted]

bullet

plant is NOT as follows: [basal leaves mostly 1-6 cm long, linear to oblanceolate or spatulate, forming a dense rosette; plants with a well-developed taproot; and either densely caespitose, seldom more than 5 cm tall, the heads sessile among the leaves, or with stout, simple stems, 5-15 (25) cm tall, heads solitary, involucres 2-4 cm wide, bracts ciliate to pectinate or fimbriate, rays blue and achenes densely pubescent, obovate to triangular]

bullet

leaves appearing BEFORE the flowers

bullet

leaves NOT extending beyond flowers

bullet

leaves alternate or basal; NOT opposite

bullet

basal leaves NOT cordate, NOT sagittate

bullet

involucral bracts either subequal and the outer leafy, or more commonly evidently imbricate, with chartaceous base and evident green tip, sometimes chartaceous throughout; NOT [involucral bracts subequal or more or less imbricate, often green in part, but neither definitely leafy nor with chartaceous base and herbaceous green tip]

bullet

bracts in several series; NOT [in 1 or 2 series]

bullet

receptacle naked

bullet

flower heads with florets both tubular and ray

bullet

ligulate flowers pistillate or neuter; NOT perfect

bullet

ray florets conspicuous

bullet

ray florets 10-50; NOT 50 or more

bullet

ray florets usually blue, purple, pink, or white; NOT yellow, NOT orange

bullet

stamens united to form a tube around the pistil

bullet

style branches ordinarily more than 0.5 mm long; NOT [style branches 0.5 mm long or less, or obsolete]

bullet

style branches lanceolate or narrower, acute or acuminate; NOT [style branches lanceolate or broader, acute to obtuse, or obsolete]

bullet

pappus of capillary bristles, at least in part; NOT [pappus of 1 or 2 short awns, a mere crown or none] 

bullet

pappus composed of numerous hairs; NOT [composed of only a few hairs]