Echinocereus relictus

Plants unbranched when young, ultimately producing 1–45 branches, forming a compact or somewhat open clump. Stems mostly erect or somewhat decumbent, cylindric or tapering apically, (6)10–30(33) cm tall, stem diameter apex (2.1)2.9–5.2(6.5) cm, average 4 cm, stem diameter at midpoint (3)3.4–6.2(7.6) cm, average 4.9 cm, stem diameter base (3.3)3.8–6.6(9.2), average 5.2 cm; ribs (10)11–14(16), average 12.5 ribs, crests slightly undulate, horizontal distance between ribs (5)5.5–15(19) mm, average 10.5 mm; areole (4)5–15.5(18) mm apart along the same rib, average 10.4 mm, height of rib to base of areole (1)3.6–5.8(9) mm, average 4.8 mm, areole diameter (2.7)3.4–5.4(6.5) mm long × (2.2)2.9–4.7(5.5) mm wide, average 4.4 mm long × 3.8 mm wide. Spines 16–22 per areole, straight or curved to twisted with polymorphic spine color of whitish to gray, yellowgold or dull yellow, reddish-brown, or dark blackish-purple spines; spine angle (negative < 90° < positive) radial spines (80°)85°–120°(160°), average 101°, central spines (85°)100°–180°(185°), average 133°; radial spine curvature 0–3 mm, average 0.25 mm, central spine curvature 0–4 (10) mm, average 1.3 mm; radial spines 10–16 per areole, length (5)5.8–11.25(14) mm, average 8.5 mm, proximal radial spine diameter (0.13)0.23–0.58(0.77) mm wide × (0.15)0.2–0.51(.67) mm thick, average 0.42 mm wide × 0.36 mm thick; central spines 3–7 per areole, length (1.2)1.5–4.5(6.1) cm, average 3.1 cm, proximal abaxial spine diameter (0.41)0.63–1.3(1.82) mm wide × (0.31)0.53–1.02(1.24) mm thick, average 1.02 mm wide × 0.78 mm thick; divergent-porrect or rarely recurved, abaxial central spine generally whitish, rarely colored, often flattened or sharply angled, sometimes terete-subterete. Flowers 5–9 cm long × 3–9 cm wide, average 7.3 × 5.8 cm; flower tube 10–20 × 10–32 mm; hypanthium 9–20 × 12–32 mm; tepals bright rose-pink to magenta, darker proximally, 30–52 × 5–20 mm, average 40.4 × 11.4 mm, apices rounded, attenuate or somewhat fimbriate or incised; stamen 18–24 mm long, anthers yellow, filaments yellowish-whitish, not motile; ovary 7–28 × 9–20 mm, nectar chamber 3–11 mm wide; style 19–28 × 1.5–4 mm; stigma 9–13 lobes. Fruits ovoid-spherical, 20–40 mm long × 20–40 mm wide, red-orangish and often splitting at maturity, pulp white-reddish-white, fruit spines detach at maturity. Seeds 1–1.5 mm, black, pitted. Ploidy chromosome count 2n = 22.

Echinocereus relictus B. Wellard, sp. nov. (Figs. 3, 4). Type: UTAH: “Limestone Road” S of Sun River Community, 1.25 mi N of  Utah/Arizona border, 1 mi W of Port of Entry, 795 m, 37.018198°, -113.632523°, 14 Apr 2016, B. Wellard 578 with K. Wellard (holotype: UT; isotype: ASU).

Echinocereus relictus possesses several characters that distinguish the species morphologically from its closest relative E. engelmannii. Some of the most notable include: greater number of ribs, shorter spacing between ribs, shorter spacing between areoles, shorter radial spines,shorter abaxial central spine, smaller radial and central spine diameters, shallower rib height to the base of the areole, and narrower stem diameter.