Polytaenia nuttallii DC. (incl. P. nuttallii var. texana), texas parsley, prairie parsley. Perennial herb, thick–taprooted, rosetted, 1–stemmed at base, erect with ascending branches along principal axes from successive nodes, in range 35—102 cm tall; shoot with ± 6 basal leaves (present at flowering) and cauline leaves diverging upward, basal leaves to 430 mm long, leaves lobed and coarsely dissected, aromatic when crushed, appearing glabrous; taproot of large plant 300+ mm long and to 15 mm thick.
Stems ridged, to 15 mm diameter, with 2 principal ridges descending from each leaf or bract, tough; solid.
Leaves helically alternate, odd–2–pinnately compound with opposite pairs of lateral primary and secondary leaflets widely spaced and having several orders of lobing and dissection, with 5 pairs of lateral primary leaflets but the upper ones sessile, terminal primary and secondary leaflet 3–lobed, pairs of lateral secondary leaflets to 3, petiolate, without stipules; petiole sheathing to midpoint with membranous margins and cylindric above, to 100 mm long, tough, sheath white changing to green or purple–tinged, upper portion to 7 mm diameter and low–ridged with tannish midstripe, soft–hairy and puberulent except on membranous margins; blade of basal leaves to 350 mm long and wide, bilateral with halves mirrow images; rachis rounded on lower side and 2 flattish upper sides forming a median ridge; primary leaflets spreading at 45—60� from rachis, to 240 mm long and secondary leaflets to 80 mm long, each decreasing from leaf base to tip and basal leaves to the uppermost cauline leaves, rachilla rhombate in ×–section, low–ridged, puberulent, smaller axes ridged and sometimes channeled, short–hairy and along channeled appearing short–ciliate; terminal and ultimate lobes mostly obovate or oblong, to 40 mm long, with shallow to deep sinuses and a mixture of sublobes and serrate to crenate margins, lobes tapered to long–tapered at base, with obtuse tooth at tip, pinnately veined with veins raised on lower surfaces and ending in teeth.
Inflorescence compound umbel, terminal, in clusters having 3—5 compound umbels with 1 terminal umbel and a pseudowhorl of usually 3 or 4 lateral branchlets with smaller compound umbels, umbel domed, to 40 mm across increasing somewhat in fruit, to 11—20+ umbellets, umbellet to 25–flowered, hemispheroid, 10—14+ mm across, with bisexual and staminate flowers, on initial compound umbel having peripheral umbellets with mostly bisexual flowers and central umbellets having mostly staminate flowers, on small compound umbel having mostly bisexual flowers throughout, bracteate, glabrous; peduncle ridged, 20—90 mm long; bract subtending lateral branchlet leaflike with sheathing petiole to 11 mm long, parallel–veined, green with wide membranous margins, blade 3–palmately divided, the terminal lobe obovate and ± symmetric with sublobes above midpoint, lateral lobes < terminal, asymmetric, and with fewer sublobes or laking sublobes and having membranous extension of sheath; on lateral axis having subopposite pair of bracts subtending future cyme and vegetative shoot; bracts decreasing upward = sheath + 3–lobed at tip; peduncle of terminal compound cyme to 25 × 2 mm, ridged and ± papillate or puberulent along ridges; involucre of bracts subtending primary rays absent; primary rays 11—15 × 1 mm, outer rays the longest and spreading; involucel of bractlets subtending pedicels of bractlets subtending pedicel acuminate–linear, < 1—6 mm long, the longest < pedicel, green, 1–veined, glabrous; pedicel ridged, at anthesis 2—4 mm long increasing in fruit, of staminate flower persistent (appearing like fruit aborted).
Flowers bisexual and staminate, ± bilateral, 2 mm across (petals not spreading); sepals 5, unequal, triangular to deltate, 0.5—1 mm long (1 larger than others), light green with whitish margins; petals 5, not spreading, heart–shaped in outline, ca. 1.6 × 1 mm, light yellow–green, with high midridge on upper surface, broadly tonguelike with whitish flap at tip (not tail–like) and tip permanently incurved, papillate near base; stamens 5, free; filaments ca. 2 mm long, yellowish (staminate flower) or cream–colored (bisexual flower); anthers dorsifixed, dithecal, 0.7—0.8 mm long, light yellow–cream, in bud hooked later spreading, longitudinally dehiscent; pollen cream–colored; pistil (bisexual flower) 1; ovary inferior with domelike, nectar–producing platform (stylopodium) on top, cupcake–shaped to wedge–shaped, ca. 1.5 × 1 × 1.5 mm, light green, 2–chambered, each chamber with 1 ovule; stylopodium amphitheatrelike, 1 × 0.6 × 0.4 mm and ca. 0.4 mm tall, green–yellow, scalloped on margins; styles 2, ascending between incurved petals, slender, ca. 2 mm long, yellowish; stigmas terminal, minute.
Fruit schizocarp, of 2 dry, 1–seeded halves (mericarps), strongly compressed front–to–back, before splitting broadly elliptic to obovate in outline, 6.5—9.2 × 3.7—5.2 mm, with slightly bulging seed chamber, tapered at base, with tan, winged margins; outer surface elliptic centrally with 3 ribs, wall brown and ribs tan, wing 1—2 mm wide.
A. C. Gibson