Castilleja rhexiifolia Rydb.

 

Castilleja rhexiifolia, commonly called rosy paintbrush, subalpine paintbrush, or rhexia-leaved paintbrush, is a species of plant in Orobanchaceae, commonly known as the broomrape family. They are a common flower found in moist habitats near or above timberline in the Rocky Mountains and the Pacific Northwest. Like most members of the Castilleja genus, they are partially parasitic plants.

Description

Castilleja rhexiifolia is a perennial plant that may be 10–80 centimeters tall when full grown, but is more often 25–60 centimeters. They have a taproot which has a woody structure at its top where the herbaceous stems regrow each year (a caudex).

Each plant may have a few or several stems that will either grow up straight from the base of the plant or grow outwards slightly before curving and growing upwards (erect or ascending). Most stems are unbranched, but occasionally they will branch. Towards the base the stems are smooth or almost smooth and hair free (glabrous to glabrate) and sparsely covered in long, soft hairs towards their ends, sometimes with gland tipped hairs (stipitate-glandular).

The leaves of Castilleja rhexiifolia may be green or somewhat tinted purple. They are variable in shape, narrow like the leaves of grass (linear leaves), a narrow or broad spear head shape wider in the middle and tapered towards the ends (lanceolate leaves), as somewhat rounded rectangle (oblong leaves), or shaped like an egg (ovate leaves) and are usually 3–6 centimeters long, occasionally reaching seven centimeters. The leaves are thin, not fleshy, with three quite visible veins, and are flat or slightly rolled inward (involute). The ends of the leaves may have three lobes or no lobes, usually with narrow points, and when present the side lobes are narrower than the central one. The bracts may be covered sparsely or densely with hairs with a slightly sticky texture (viscid-pilose).

Castilleja rhexiifolia has relatively large showy inflorescences, 2.5–15 centimeters long and 1.5–4.5 centimeters wide, with large brightly colored modified leaves (bracts) surrounding the flower that may be pink-purple, red-purple, purple, or crimson. More rarely they may be a pale reddish, yellowish, or white. Usually the bracts are the same color from base to tip, but occasionally they will be greenish, a dull brown-purple, or deep purple near the base with any of the other colors on the rest of the bract. The modified leaves have a similar shape to the photosynthetic leaves, broad spear head shaped, egg shaped, or with a teardrop shape with the broadest part towards the end (obovate). They may have no lobes at the end of the bracts or as many as seven, but most commonly 3–5 lobes that form past the mid-point of the bract. The central lobe will have a blunt and broad point, while the ones to the side will be more sharply rounded and only sometimes rounded.

The sepals are united into a tube (a calyx) which almost entirely conceals the flower and has the same bright color as the bracts with green, purplish, or whitish coloration at the base. The sepals are 15–25 millimeters in length with divisions towards the ends that are 40–50% of the length at the top and bottom (abaxial and adaxial) and 15–30% of the length at the sides. The lobes formed by these clefts are oblong to triangular in shape, usually with blunt or rounded ends. The petals (corolla) of Castilleja rhexiifolia are united into a tube for much of their length, but they are almost entirely concealed within the sepals. The corolla is straight and 15–36 millimeters long, though usually shorter than 30 millimeters. The tube portion can range from 11 to 24 millimeters in length, though more often is 12–24 millimeters. The top of the corolla splits into a beak that protrudes from the sepals and is about 7–12 millimeters long, about 1/3 the length of the corolla. The lower lip of the corolla is deep green and smaller, 1–3 millimeters. The lower lip has three small lobes commonly called "teeth" 0.5–2 millimeters long that curve inwards. Overall the petals are green, yellow, or slightly red colored.

In its native range it flowers from May through September, with occasional blooms as early as March. The fruit is a capsule around 12 millimeters long.

Castilleja rhexiifolia is most often confused with Castilleja miniata, another similarly colored paintbrush flower that somewhat overlaps in habitat and range with it. It may also be confused with Hayden's paintbrush (Castilleja haydenii), another similarly colored high altitude species, but C. rehexiifolia is typically taller and the majority of the leaves are without lobes or have three lobes at most, while C. haydenii has typically has three or more.

Castilleja rhexiifolia - Wikipedia

Pink & Red Wildflowers - Rocky Mountain National Park (U.S. National Park Service) (nps.gov)