Curtiss' Loosestrife

Description

Perennial herb, sometimes shrub-like due to overwintering prostrate stems. Lythrum curtissii is a slender, multi-branched plant to 1 m tall, capable of producing stems from a persistent woody base at ground level. The leaves are opposite below, mostly alternate above, lanceolate to oblong to elliptic, the largest to about 5 cm long and 0.5 cm wide, those on the branches abruptly reduced and well-spaced. The small flowers are produced in the axils of the leaves on the secondary branches. The flowers of an individual plant have either the stamens prolonged ( -thrum- flowers) or the style prolonged ( -pin- flowers), as depicted in the illustration. The calyx is composed of six sepals, the lobes about 0.5 mm long and pointed, alternating with similarly shaped appendages. Both calyx lobes and appendages arise from a strongly ribbed, cylindrical, floral tube that is 3-4 mm long and somewhat purplish-tinged. The six petals are deep purple, up to 3 mm long, borne singly on the floral tube, and quickly withering. The fruit is a capsule. Flowering period: June to August; fruiting period: September to October. Best search time: during flowering, since lower stem leaves tend to fall off later in the season