RESULTS - MONTANA 



Asclepias ovalifolia Dene. 

 Asclepiadaceae 

 Ovalleaf milkweed 

 A. Description 



1. General description: Herbaceous perennial, stems mostly 

 single or paired; simple or branched, upright and 2-6 dm (7.9- 

 2 3.6 in) tall. Leaves mostly opposite; blades lanceolate to 

 broadly ovate. Flowers creamy white, stamens evolved into a 

 column to which are attached sac-like "hoods", each hood with 

 an incurved "horn" appendage. Approached peak flowering on 2 

 July 1994, with a few plant in very early stages of fruit 

 formation. 



2. Technical description: Perennial herb from a shallow, 

 slender rhizhome. Upright stems mostly solitary or paired 

 from a simple to branched and somewhat thickened base, simple, 

 slender (1)2-6 cm tall, sparsely to densely villous. Leaves 

 mostly opposite or subopposite, blade lanceolate to broadly 

 ovate, erect to spreading, (2)4-8 cm long, (1)1.8-4.5 cm wide, 

 firmly membranaceous, sparsely to moderately villous, 

 especially beneath, apex broadly acute to rounded, 

 occasionally mucronate, margins flat to slightly revolute, 

 base obtuse to rounded; petiole 0.1-1 cm long. Inf loresences 

 1-3, terminal or subterminal, (4) 8-20 flowered; peduncles 0.5-3 

 cm long or infloresence sometimes sessile; pedicels filiform, 

 15-20 mm long, puberulent. Flowers 8-10 mm tall; calyx lobes 

 green to purple, lanceolate to ovate, 2.3-3.5 mm long, 

 villous. Corolla lobes greenish-white, often purple-tinged 

 dorsally, elliptic-lanceolate, reflexed, 5-6 mm long, sparsely 

 to moderately puberulent dorsally; gynostegium greenish-white 

 to cream or yellow, briefly stipitate, glabrous; column 

 obconic, 0.4-0.6 mm tall, 1.2-1.8 mm wide. Hoods elliptic- 

 oblong, attached near base, spreading, 3.8-5 mm long, not 

 fleshy, freely open above, the apex rounded, plane, ca 2 mm 

 higher than the anther head, the margins with a pair of 

 triangular lobes below the midpoint, the base not saccate. 

 Horns falciform, adnate to lower 1/3 of hood, arching over the 

 anther head, 0.7-0.8 X longer than the hood; fleshy pads 

 obscure, narrowly bilobed. Anther truncate-conic, 1.6-2.5 mm 

 tall, 2.2-3 mm wide; anther appendages ca 1.1 mm long; anther 

 wings abruptly rounded at base, not notched, scarcely spurred, 

 ca 1.8 mm long. Follicles fusiform, erect on deflexed 

 pedicels, 6-8 cm long, 0.8-1.3 cm thick, without tubercles, 

 densely puberulent; seeds ovate, 5.5-7 mm long; coma tan, 1.8- 

 35 cm long (from Great Plains Flora Association 1986) . 



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