Cactaceae (Cactus Family)

Succulent perennials, with fleshy stems that are columnar, globose, or flattened, commonly jointed. They are leafless except for small, narrow leaves on young Opuntia stems. Flowers have numerous petal-like segments, the outer sepals intergrading with the inner petals. The pistil is surrounded by many stamens. The ovary is inferior, that is, below the petals. The fruit is commonly dry, but in some species it is fleshy enough to be used as a food.

Echinocactus polycephalusEngelm. & Bigelow. Cottontop Cactus. (Plate 6.54) Usually clumps of a few to many large cylindrical or spheroid stems, 6–20 in (1.5–5 dm) long, 8–12 in (2–3 dm) thick, gray-green in color. Spines are rigid and sturdy, the central ones 1 1/2–2 1/2 in (3.8–6.4 cm) long. Flowers are at the apex of the stem, each bloom about 2 in (5 cm) across, surrounded with white, cottony growth. Few see them, however, because they appear in midsummer. Fruit is dry, partially buried in the "cotton." Flower: Yellow.

Distribution. Dry, rocky slopes; Inyo Mountains; Desert Scrub, below 5,000 ft (1,524 m).

Echinocereus engelmannii(Parry) Lemàine var.chrysocentrus(Engelm. & Bigelow) Engelm. Engelmann Cactus, Torch Cactus. (Plate 6.55) Usually 3 to 10 cylindrical stems, 5–12 in (12–30 cm) high, 2–2 1/2 in (5–6.4 cm) in diameter, ribbed. Spines vary in color, with the lower central one white, 1–3 in (2.5–8 cm) long. Flowers are borne laterally rather than terminally, each 2–3 in (5–8 cm) across. Fruit is green, turning red when mature, 3/4–1 1/4 in (2–3 cm) long. It is edible and nutritious. Flower: Purple to magenta or lavender.

Distribution. Rocky and gravelly places; Desert Scrub and Pinyon-juniper Woodland, below 7,000 ft (2,134 m).

Echinocereus triglochidiatusEngelm. var.mojavensis(Engelm. & Bigelow) L. Benson. Mojave Mound Cactus. (Plate 6.56) Stems in dense mounds up to 1 ft (3 dm) high and 1–4 ft (3–12 dm) in diameter. They are ovoid to oblong, 2–6 in (5–15 cm) long, mostly 2–3 in (5–8 cm) in diameter, ribbed, and slightly nippled. Spines vary in color. Flowers are 1 1/2–2 in (4–5 cm) across. Fruit is red, 1/2–1 in (1.3–2.5 cm) long. Flower: Bright red.

Distribution. Limestone outcrops; Desert Scrub to Subalpine Zone, 5,000–10,000 ft (1,524–3,049 m).

Opuntia basilarisEngelm. & Bigelow. Beavertail. (Plate 6.57) Clumps 6–12 in (15–30 cm) high of flat, jointed stems. Joints are blue-green to purplish, mostly obovate or round, and 2–6 in (5–15 cm) long. There are no spines, but fine, barbed glochids are troublesome. Flowers are about 2–3 in (5–7.7 cm) across. Fruit is green, becoming tan or gray, dry, and 1–1 1/4 in (2.5–3 cm) long. Flower: Cerise or rose to orchid.

Distribution. Widespread; dry gravelly and rocky places; Desert Scrub and Pinyon-juniper Woodland, up to 6,000 ft (1,829 m).

Opuntia erinaceaEngelm. & Bigelow var.erinacea.Mojave Prickly Pear. (Plate 6.58) Growth habit similar to Beavertail, but joints are more elongated and are spiny throughout, the spines somewhat flexuous. Flowers are 1 3/4–3 1/2 in (4.5–9 cm) across. Fruit is dry and densely spiny. Flower: Yellow.

Distribution. Sandy or gravelly places; mostly in Joshua Tree and Pinyon-juniper Woodland, Desert Scrub and Pinyon-juniper Woodland, below 9,000 ft (2,743 m).

Var.ursina(A. Weber) Parish. Old Man Cactus, Grizzly Bear Cactus. Growth habit similar to var. erinacea . Joints with long, flexuous, white or gray spines throughout. Flower: Yellow.

Distribution. Rocky places, such as Joshua Flats; Inyo Mountains; Desert Scrub and Pinyon-juniper Woodland, 5,500–7,500 ft (1,677–2,287 m).

Var.utahensis(Engelm.) L. Benson. Utah Prickly Pear. Joints mostly 2–3 1/2 in (5–9 cm) long. Spines flexuous only on upper portion of stem. Flower: Yellow.

Distribution. Desert Scrub and Pinyon-juniper Woodland, much the same as Old Man Cactus, and they seem to intergrade.

Sclerocactus polyancistrus(Engelm. & Bigelow) Britton & Rose. Mojave Fishhook Cactus, Pineapple Cactus. (Plate 6.59) A small barrel-like cactus with stems usually solitary, pineapple-shaped, 4–10 in (10–25 cm) long, ribbed, and with low nipples. The spines, which almost obscure the stem, include red hooked ones spreading outward and white radial ones close to the stem. Flowers, about 2 in (5 cm) across, are in a ring on the summit. Fruit is dry, about 1 in long. This is an endangered species because it appeals to collectors, but it does not survive when transplanted. Flower: Rose-purple to magenta.

Distribution. Rocky places, mostly on limestone; Desert Scrub and Pinyon-juniper Woodland, 6,000–7,700 ft (1,829–2,348 m).