Erodium texanum A. Gray, texas filaree, heronbill. Annual, taprooted, rosetted, 1—several–stemmed at base, with decumbent branches axillary to basal leaves = inflorescences, in range 7—25 cm tall; shoots with alternate basal leaves but opposite bracts (cauline leaves) on flowering lateral branches, short–hairy, foliage lacking glandular hairs and not scented.
Stems cylindric (also inflorescence axis), at base of plant.
Leaves helically alternate, ± pinnately 3–lobed with 2 basal lobes (“palmately”), long–petiolate, with stipules; stipules 2, = wings at the base of petiole, fused 2—3 mm, narrowly triangular, 7—9 × 1.5—2 mm, opaque white or with some green and rose, short–ciliate on margins, acuminate at tip, 1–veined; petiole cylindric above compressed white portion with stipules, < 30—75 mm long, green or reddish on exposed side, short–hirsute with downward–pointing hairs; blade symmetric ovate to triangular in outline, 14—40 × 10—31 mm, often with a pair of basal lobes having sinus to midpoint from midrib, basal lobes often with 2 sublobes, the lower sublobe often overlapping and concealing petiole, other lobes of margin more weakly defined and having shorter sinuses, cordate to truncate or subtruncate at base, crenate on lobe margins, ± obtuse at tip, pinnately veined with principal veins sunken on upper surface and raised on lower surface, upper surface dull green or with purplish principal veins, lower surface paler, short–strigose with denser hairs along veins.
Inflorescence cymelike array with umbel, axillary shoot from a basal leaf, umbel 2—4–flowered, flowers erect at anthesis nodding by nightfall, bracteate, stiff–hairy and lacking glandular hairs; axes cylindric, internodes to 90 mm long; flowering shoot with 1—several nodes having opposite bracts (cauline leaves) with stipules fused between petioles into 2 triangular, = 2 2–lobed stipules 6—7 mm long, stipules colorless except each with 2 green veins, surfaces short–hairy; peduncle axillary to bract, cylindric, at anthesis to 30 mm long increasing in fruit, densely short–strigose; involucre of bractlets subtending pedicels of an umbel, bractlets 4, somewhat fused at base, lanceolate to narrowly ovate stipules, ca. 4 × 1.2—2 mm, scarious and colorless except for green veins, each stipule 1–veined; pedicel with pulvinus at base, initially ascending with hook at tip, at anthesis 5—5.5 mm long, becoming strongly bent > 90° in fruit, green aging purple–red just before maturity, densely short–hairy.
Flower bisexual, radial, 19—28 mm across; sepals 5, at anthesis spreading, outer 2 sepals overlapping inner 3 sepals, with short points at tip (apiculate); outer sepals ovate, 7—9 × 3.2—4 mm increasing to 12 mm long and erect in fruit, green with 5 darker stripes from base (veins) and colorless margins 0.3—0.4 mm wide, short–ciliate on margins, having 5 raised veins on outer (lower) surface and densely white short–strigose with upward–pointing hairs, inner surfaces sparsely short–strigose; inner sepals ± elliptic, slightly smaller than outer sepals, with 3 raised veins on lower surface and 1 or 2 wide membranous margins; petals 5, ovate, 13.8—15.5 × 8.5—11.8 mm, purple with white at narrowed base, having 7—9 veins raised on lower surface, between white and purple having hirsute hairs on upper surface; nectaries 5, appressed to bases of stamens (alternate with petals), small domes, green, nectar–producing forming droplets; stamens 5 fertile opposite sepals, staminodes 5 opposite petals, free; filaments erect, 5—6 mm long, with colorless wings to midpoint, ca. 0.5 mm wide lobed at top, cylindric above wings ± 2.5 mm long, greenish; anthers dorsifixed, dithecal, 1.5—1.7 mm long, orangish strawberry–colored, longitudinally dehiscent; pollen yellow–range; staminodes fused in ring at base, 2.5—3.5 mm long; pistil 1, at anthesis 4—7 mm long; ovary superior, 5–lobed, ca. 2 mm diameter, lobes hemispheroid, green but covered with dense, upward–pointing, whitish hairs (appearing sericeous), 5–chambered, each chamber with 1 ovule attached to center; style a column with 5 free, suberect to ascending tips, column short–hairy with upward–pointing hairs, the branches stigmatic, 0.7—0.9 mm long, purple–red, short–papillate.
Fruit schizocarp, of 5 dry, 1–seeded mericarps, before dehiscence erect to ascending, needlelike (= beaks of style column) with swollen base (= seed bodies) and style column 5–sided with channels, mericarps separating from base initially by coiling downward (= awn) from the persistent portion of style column, 53—73 mm long before splitting; seed body oblanceoloid, 7—9 × 1.5 mm, sharply pointed and curved at base, brown, narrowly open on inner edge, densely appressed hirsute with upward–pointing hairs, with deep concavity at top forming a diagonal collar above a series of other indentations, surface of seed body hairs with circular depressions, brown, becoming tightly helically twisted forming an erect shaft with ca. 5—6 gyres to below midpoint and having a long, horizontally curved terminal portion, brown, short–strigose on outer surface and with long, straight fibers to 4 mm long on inner side; filaments and staminodes erect in immature fruit; peduncle in fruit to 50 mm long and ascending.
Seed tightly fitting within seed chamber, oblanceoloid, ca. 4 × 1 mm, dark orange, seed coat thin, hilum slender line ca. 1.5 long on narrow portion.
A. C. Gibson