Fl. Bor.-Amer. 1: 207. 1803.
Plants perennial, cespitose or arborescent, acaulescent to short-caulescent, scapose, from branched, woody caudices or bulblike structures; usually forming colonies with few to many rosettes. Stems to 25 dm. Leaves forming rosettes; blade linear, not rigid or fibrous, bases broadly expanding, margins serrulate or entire. Scape 0.5–25 dm. Inflorescences paniculate, rarely racemose, 3–18 dm; bracts caducous or occasionally persistent. Flowers 2–5 per node, functionally unisexual, pistillate flowers with staminodes, staminate flowers with reduced pistils; tepals white to cream or tan, 1.3–5 mm, apex glandular; ovary superior; pedicel jointed near middle. Fruits capsular, 3-locular, 3-lobed, thin-walled or sometimes firm-walled, often inflated, mostly notched at base and apex or rounded distally; dehiscent, often splitting irregularly. Seeds closely or loosely invested in capsules, globose, turgid. x = 19.
North America (se and sw United States), n and nc Mexico.
Species ca. 30 (14 in the flora).
In areas of west Texas, New Mexico, and Arizona, the species of Nolina are not always well defined. There is variation in the presence or absence of marginal teeth on the leaves and placement of the inflorescences within or beyond the leaves. Collectors should take good notes about the plant habit and morphology and include these with their collections. Further study is needed on Nolina throughout its range. Some species of Nolina are extremely infrequent. Some are on federal and/or state rare and endangered species lists, and possibly some of those listed with a state should be listed federally.
J. C. Dice (1988) studied section Arborescens of Nolina in the United States, and presented extensive descriptions and discussion of N. bigelovii, N. parryi, N. cismontana, and N. interrata.
|1||Plants caulescent.||> 2|
|1||Plants acaulescent.||> 5|
|2||Leaf margins entire, filiferous.||Nolina bigelovii|
|2||Leaf margins serrulate, not filiferous.||> 3|
|3||Inflorescence bracts caducous; Texas.||Nolina erumpens|
|3||Inflorescence bracts persistent; California.||> 4|
|4||Stems to 4 dm, occasionally to 15 dm; leaf blades 12–30 mm wide; scape 14–35 mm diam. at base.||Nolina cismontana|
|4||Stems 5–21 dm; leaf blades 20–40 mm wide; scape 26–90 mm diam. at base.||Nolina parryi|
|5||Subterranean caudices horizontal; leaf blades glaucous, 1.2–3.5 cm wide; California.||Nolina interrata|
|5||Subterranean caudices vertical; leaf blades not glaucous, or if glaucous then no more than 8 mm wide; Arizona, Colorado, Florida, Georgia, New Mexico, Oklahoma, South Carolina, Texas.||> 6|
|6||Leaf margins entire or only slightly roughened, with widely separated, noncartilaginous teeth.||> 7|
|6||Leaf margins serrulate, with close-set, cartilaginous teeth, or occasionally entire.||> 9|
|7||Inflorescences usually conspicuously tinged purple, main rachis and divisions slender, flexible; fruiting pedicels slender distal to joint, typically to 2.5 mm, articulate near middle, not noticeably dilated; tepals 1.9–3.2 mm; se New Mexico, w Texas.||Nolina micrantha|
|7||Inflorescences not purple or rarely so, main rachis and divisions thick, rigid; fruiting pedicels thick distal to joint, (1–)4–7 mm, articulate near base, noticeably dilated into perianths; tepals 2–3.5 mm; s New Mexico, Texas.||> 8|
|8||Leaf blades slightly concavo-convex toward base, triangular, 2–4(–7) mm wide; inflorescences 25–70 cm, lateral branches ascending; seeds 2.6–3.4 mm diam.; rocky habitats of limestone; s New Mexico, Texas.||Nolina texana|
|8||Leaf blades flat or concavo-convex, 5–10 mm wide; inflorescences 40–70 cm, lateral branches spreading; seeds 4.3 mm diam.; sandy soils or dunes; w Texas.||Nolina arenicola|
|9||Leaf blades flattened.||> 10|
|9||Leaf blades concavo-convex.||> 12|
|10||Capsules 6–11 mm diam.||Nolina lindheimeriana|
|10||Capsules 3.5–7 mm diam.||> 11|
|11||Capsules asymmetrical, up to 5.5 mm diam.; seeds closely invested in capsules; Florida.||Nolina atopocarpa|
|11||Capsules symmetrical, 5–7 mm diam.; seeds loosely invested in capsules; Georgia, South Carolina.||Nolina georgiana|
|12||Capsules 8–12 mm diam.||Nolina brittoniana|
|12||Capsules 3.5–6.4 mm diam.||> 13|
|13||Bracts persistent; capsules distinctly notched distally; se Colorado, e New Mexico, w Oklahoma.||Nolina greenei|
|13||Bracts caducous; capsules indistinctly notched apically; Arizona, New Mexico, Texas.||> 14|
|14||Fruiting pedicels distal to joint to 2.5 mm; inflorescences not surpassing leaves; seeds 1.5–2.5 mm; w Texas.||Nolina erumpens|
|14||Fruiting pedicels distal to joint 3–6 mm; inflorescences surpassing leaves; seeds 2.2–3.4 mm; Arizona, New Mexico.||Nolina microcarpa|