Perennial herb, 10 – 40 cm in height, erect; bulb c. 2.5 × 1.5 cm, ovoid, tunics papery, brown to dark brown, neck 18 – 66 mm long, comprising narrowly linear projections of the tunics. Leaves basal and cauline, linear, acuminate, parallel-veined and longitudinally plicate, scabrid on the veins and margins, plant otherwise glabrous; basal leaves 1 or 2, 11.5 – 32.5 × 0.1 – 0.3 cm; stem leaves 1 – 3, 8.0 – 30.2 × 0.15 – 0.25 cm. Inflorescences cymose, 2 – 4 flowered; peduncles 1.5 – 20.3 cm long, sulcate; bracts 2 – 5, 30 – 52 × 4 – 6 mm long, lanceolate to narrowly elliptic or oblanceolate, concolorous with leaves to purple-hued, turning russet-brown and drying out from the tips in fruit, clasping each other at base for up to 12 mm, apex acuminate, margins translucent; pedicels 31 – 34 mm long, terete, ±erect so flowers are held erect; tepals free; outer 27 – 42 × 12 – 21 mm, obovate-spathulate, the ventral surface blue, the centre with white lines and dark blue irregular patches, the dorsal surface sky-blue, base an ascending (8 –) 10 – 12 mm long claw, blade 19 – 34mmlong, obovate to oblong-obovate, spreading to recurved, more recurved towards obtuse apex; inner 5 – 7 × 1 – 2 mm, oblanceolate, erect, blue, acuminate; filaments fused to form a 10 – 13 mm long, erect column, anthers 9 – 11 mm long, narrowly oblong, flat and appressed to each of the 3 style branches; style branches 9 – 16 mm long, lorate in outline with a longitudinal central furrow, apically bifid for 3 – 5.5 mm and divided into 2 – 7 concolorous lobed crests which are apically stigmatic; ovary 5 – 8 × 2 – 2.5 mm oblongoid-claviform, glabrous. Fruit a dry capsule, seeds numerous, subspheroidal, angled, surface smooth, yellowish.
Although very restricted in distribution, this species is well adapted to disturbance, which possibly favours its spread, so it is considered to be Least Concern (LC) at present. However, since it is horticulturally attractive, it might be vulnerable to uprooting for cultivation in gardens so careful monitoring of its populations is desirable.
Mastigostyla cardenasii is distinguished from M. chuquisacensis and other species by its long, 2 – 7- crested style branches, 9 – 16 mm in length, acuminate inner tepals and the obovate-spathulate, 27 – 42 × 12 – 21 mm outer tepals which have a (8 –) 10 – 12 mm long, narrow basal claw and a 19 – 34 mm long blade.
In the inter-Andean valleys and subpuna vegetation of Cochabamba Department in Bolivia
A plant of bare open, stony banks and field borders (occasionally growing as a weed of cultivation); 2500 – 3900 m.
Flowers towards the end of the rainy season from February to April.
Mastigostyla cardenasii is frequent but scattered in occurrence in Cochabamba Department in Bolivia but has never been found anywhere else except for the type collection at Cusco in Peru. This is a highly improbable natural distribution and we cannot trace any other species with a similar disjunct distribution. It seems likely that Cárdenas made some error in labelling the specimen especially as the Cusco area is quite well known botanically. At least one other case of mislabelling of a type collection by Cárdenas is known. Hippeastrum incachacanum (Amaryllidaceae) was supposedly collected at Incachaca in Cochabamba Department (Cárdenas 1965) but actually comes from the Río Surutu in Santa Cruz Department (Vásquez 2001). Furthermore, we have been informed by Mr Raul Lara, who knew Cárdenas personally and has studied his itineraries and collection numbers, that Cárdenas 2337 dates from 1933 (not 1943) when Cárdenas was collecting mainly in Potosi Department. There is no evidence that he went to Cusco at this time or indeed in 1943. For these reasons we think Brako & Zarucchi (1993) were correct to exclude it from their Catalogue of flowering plants of Peru and that it should be considered an endemic species of the Bolivian inter-Andean valleys. Foster (1962) gives the outer tepal dimensions of Mastigostyla gracilis as to 3 cm × 8 mm. However, his measurements were taken from one poorly preserved type collection in which there has been damage to and shrinkage of the tepals; it clearly falls within the variation of M. cardenasii.