Malvastrum aurantiacum

(Scheele) Walpers

Ann. Bot. Syst. 2: 153. 1851.

Common names: Texas false mallow
Endemic
Basionym: Malva aurantiaca Scheele Linnaea 21: 469. 1848
Synonyms: Malvastrum wrightii A. Gray
Treatment appears in FNA Volume 6. Treatment on page 295. Mentioned on page 294.

Subshrubs, 0.4–1 m, sparsely branched in proximal 1/2. Stems usually procumbent and ascending, hairs appressed, (6–) 8–10-rayed, sublepidote. Leaves: stipules persistent, lanceolate, subfalcate, 4–6 × 1–1.5 mm, apex acute; petiole 10–25 mm; Inflorescences axillary solitary flowers; floral bracts absent. Pedicels 3–5 (–10) mm in flower, to 2 mm in fruit; involucellar bractlets basally adnate to calyx for 2–3 mm, deltate-cordiform in distal 4–6 mm, abruptly narrowed, 8–10 × 3–5 mm, shorter than calyx lobes, apex acute. Flowers: calyx connate 1/3–1/2 its length, broadly campanulate, lobes slightly auriculate at base, 11–12 mm, to 13–17 mm in fruit, surface hairy, hairs scattered, appressed, stellate-lepidote; corolla widespreading, golden yellow to pale orange-yellow, 30 mm diam., petals obovate, conspicuously asymmetrically lobed, 12–16 × 10–15 mm, exceeding calyx by 7–8 mm; staminal column 4 mm, glabrous; style 12–16-branched. Schizocarps 9–10 mm diam.; mericarps readily shed from calyx, 12–16, 4–6 × 4–6 × 1–1.5 mm, widely-notched, with 1 conspicuous, distally-directed, medial-apical cusp 1.5–2.3 mm and 2 distal-apical, contiguous, flattened, obtuse cusps 1 mm, surface sparsely hairy, hairs both erect and appressed, rigid, simple on apex and minute, stellate on dorsal 1/3, sides smooth. Seeds 2–3 mm. 2n = 36.


Phenology: Flowering spring–summer, into fall when sufficiently wet and warm.
Habitat: Restricted to heavy clay soil of river floodplains in prairies, especially in the Texas Coastal Bend
Elevation: 0–300 m

Discussion

Malvastrum aurantiacum is easily distinguished from the other species of the genus in the flora area by its wide, auriculate involucellar bractlets and its raspberry-red fruits when fresh, these later drying brown.

Selected References

None.

Lower Taxa

None.

"/3" is not declared as a valid unit of measurement for this property.

... more about "Malvastrum aurantiacum"
acute;acute +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
Steven R. Hill +
(Scheele) Walpers +
nearly truncate +  and cuneate +
Malva aurantiaca +
asymmetric +  and symmetric +
3-lobed +, unlobed +, wide-ovate +  and lanceolate +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
narrowed +  and deltate-cordiform +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
campanulate +
accrescent +
indehiscent +  and loculicidal +
Texas false mallow +
golden yellow +  and pale orange-yellow +
30 cm300 mm <br />0.3 m <br /> (?) +
widespreading +
campanulate +
0–300 m +
sparse;copious +
pistillate +  and staminate +
unisexual +  and bisexual +
depressed +  and not inflated +
Restricted to heavy clay soil of river floodplains in prairies, especially in the Texas Coastal Bend +
stellate-lepidote +
minute +
axillary +  and terminal +
tough-fibrous +
connate +  and distinct +
simple +, stipulate +, sessile +, subsessile +  and petiolate +
distichous +  and alternate +
auriculate +
denticulate;dentate-serrate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
brown +, tan +  and drying +
dehiscent +  and indehiscent +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
distal-apical +
glabrous +  and hairy +
flattened +  and widely-notched +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
(5-)8-18-carpellate +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0 cm0 mm <br />0 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
adnate +  and distinct +
12mm;16mm +
lobed;obovate +
1 cm10 mm <br />0.01 m <br /> (?) +  and 1.5 cm15 mm <br />0.015 m <br /> (?) +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Flowering spring–summer, into fall when sufficiently wet and warm. +
Ann. Bot. Syst. +
9mm +  and 10mm +
reniform +
0.2 cm2 mm <br />0.002 m <br /> (?) +  and 0.3 cm3 mm <br />0.003 m <br /> (?) +
persistent +
sessile +  and subsessile +
4 cm40 mm <br />0.04 m <br /> (?) +
filiform +, linear +  and capitate +
1-2 times number of carpels +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
subfalcate +  and lanceolate +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
12-16-branched +
Malvastrum wrightii +
Malvastrum aurantiacum +
Malvastrum +
species +
perennial +  and annual +
monoecious +, dioecious +  and hermaphroditic +